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1. Agricultural Impact on Groundwater QurlityThere has been an increasing awareness within Iowa of the impact of agriculture on groundwater quality. The data of Iowa Geologic Survey scientists from studies in northeast Iowa have focused attention on the Big Spring Basin area. A project to intensively study groundwater in the Big Spring Basin is underway. The project includes the active cooperation and participation of the following agencies: ISU Agricultural Experiment Station, Clayton County Soil Conservancy District ISU Cooperative Exten... |
2. Application of the Ceres-maize Model to Maximum Yield ResearchMaximum yields are obtained when as much assimilate as possible is partitioned into the grains of corn. The amount partitioned into the grains depends on several major factors. Grains per unit area is probably the most important of these factors. Other important considerations for grain filling in- clude the duration of the grain filling period, the amount that can be repartitioned from stem storage to the grains, the photo- synthesis rate, and the temperature. Several factors influence the numb... |
3. Bandded Phosphorus Applications to Winter Wheat - 1985-86While many producers recognize the importance of a sound P fertilization program for profitable wheat production? there are many potentially responsive wheat acres not receiving any fertilizer P - resulting in reduced grain yields and farmer profitability. over the years there have been many research studies conducted by land grant Universities throughout the Great Plains indicating the importance of fertilizer P applications for wheat production on low P testing soils. In the mid to late 1970's... |
4. Educational Applications of Digitized Soil SurveysThe North Dakota Agricultural Experiment Station Soil Survey of McHenry County Organized Irrigation Districts is approaching publication and represents a first for soil survey in North Dakota. The decision was made to digitize the soil maps to facilitate acreage tabulations and improve methods of generating soil interpretations. While the digitization procedure is costly in terms of start-up labor (programming) and data entry, the benefits allow more flexibility than conventional soil surveys. T... |
5. The Effect of Sulfur Fertilization of Yield and Quality of Corn and AlfalfaThe importance of sulfur (S) fertilizers for crop production in Minnesota has been recognized for several years. Inpast research, the use of S had increased crop production only on the sandy soils. Since the soil organic matter is a major reservoir of S for plant use, there is always some question about the need for S in a fertilizer program where soils are not sandy but, yet, have a low organic matter content. It is well known that S is an important component of some amino acids in wlants and t... |
6. The Effects of Rate and Timing of Nitrogen Applications on the Yield and Nitrogen Recovery of Irrigated CornHigh crop yields require that adequate amounts o f N be present and available to the root at the times it i s needed to support growth. However, for a production system to be efficient in the use of the nitrogen and to minimize any potential adverse environmental effects, care must be used to minimize loss during the growing season and minimize amounts of residual N remaining in the soil at the end of the cropping season. This requires that proper N rates be applied and that the N be applied in ... |
7. Fertilizer Use Vs. Crop ProfitsGrowing crops in farming is a complex that large investments in land and equipment, as well as considerable borrowing of money for capital. With these costs and low commodity most keenly of continuing difficulty in rnaintaining in operations. Usually farmers do not have much control over their fixed costs i n crop production. Variable costs. however-, can sometimes be adjusted. some of adjustments can reduce if the has not based his cost on wise judgement, backed with technical expertise. If one... |
8. How Fertilizer Dealers Use Research InformationThere i s not a great deal o f resource information t o draw from i n reference t o the t i t l e so most o f my comments are based on observations made and personal opinions formed during some 26 years of experience in the fertilizer industry, covering a majority of the principal agricultural states. Fertilizer dealers as a whole tend t o translate research information into dollars. They use it as a business tool. It provides support t o the sale of existing products and services and identifies... |
9. Influence of Tillage Systems on Corn Yields and Soil Test ValuesA long term tillage study was initiated at the Greenley Memorial Research Center (Novelty, MO) in 1976 to look at the effects of 4 tillage systemsoncornproduction. Thestudywasinitiatedandconductedby researchers in the Agricultural Engineering Department. Agronomy has become involved in the study beginning in 1985 to assess the effects of tillage systems on soil chemical and physical properties. The upland soils at this site are poorly drained and are generally refered to as "claypan" soils. The ... |
10. New Techniques and Methods of Disseminating Information in View of Budgetary Constraints by the University of IllinoisThe Cooperative Extension Service a t the University faces increased demands for educational services. This increaase is in an environment marked by increasing costs, and stable to decreased financial support--especially from the Federal partner. The situation we face in Illinois is similar to that faced by many other State Cooperative Extension Services. We are better o f f than some states--worse o f f than others. What of the future? Will we be able to deliver viable programs to farmers and a... |
11. Potassuim Chloride Fertilization and Common Root Rot of BarleyCommon root rot (CRR, incited by Cochliobulus sativus) is one of the most widespread diseases of wheat and barley in the Great Plains and Prairie Provinces. Average yield losses, based on extensive surveys in the Prairie Provinces, average around 5% for wheat and 10% for barley, althoughinindividualfieldslossescanbemuchhigher. Potassium chloride fertilization has been effective in reducing CRR of barley in North Dakota, and I believe we are close to understanding why CRR is reduced by KC1 fertil... |
12. Presenting Key Issues in a Rational Manner to the Non-Ag CommunityA quick scan of the program for your workshop might lead one to believe my subject is out of place here. In terms of agricultural credentials, I could certainly be consideredoutofplace: Iconsidermyselfajournalist gone straight; I was educated as a journalist and was a reporter for The Kansas City Star before entering public relations work and then joining Monsanto nearly 20 years ago. But I don't believe either the subject or the speaker is out of place for this gathering. And I think perhaps mo... |
13. Residual Effects of P Fertiliration Lessons for the EightiesSeveral states in the North Central Region have established long-term phosphorus studies. These experiments were designed to evaluate the residual effects of P fertilizer and also generate P soil test calibration data in a situation where a range of soil test levels exist on one soil. These data are extremely useful for evaluating year-to-year fluctuations in crop response to soil test P and establishing response probabilities at a given soil test level. Valuable lessons can also be learned from... |
14. Rye Cover Crops in No-till Corn ProductionField studies have been conducted for several years in Ohio to determine the effects of including a ry.e cover crop in no-till production situations. These studies were conducted at two locations, on a moderately well drained Canfield silt loam at Wooster, and a very poorly drained, but tiled, Hoytville silty clay at Hoytville. At Wooster, no-till corn was planted into corn or soybean residue, with or without a fall-seeded rye cover crop (2 bu/A seeding rate). Individual plots received 200 lb N/... |
15. Using Sufficiency and Recommendation Information to Calculate Fertilizer Response Curve and Profitability Estimates.The importance of sound fertility programs in efficient, profitable farming operations is well known - especially in times of low crop prices. Likewise, the importance of a sound soil testing program - and recommendation guidelines that relate these soil test values to credible, long-term research results - is recognized as the best way of obtaining maximum economic returns from fertilizer dollars. Unfortunatly, there are few tools available for evaluating the profitabi1it.y of a specific fertil... |
16. Basic Considerations of Soil Compaction, Tillage, and Crop ProblemsSoil compaction is one of the mosc challenging variables in crop production in the Midwest. It affects early crop growth and can lead to yield reductions. The most unusual aspect of soil compaction is the variety of crop symptoms that can develop. Few absolute answers are available on the topic of soil coapac- tion. Our research is lixited to the effects of different soil conditions on yields and some early synptoms that can be caused by soil compact ion. We have developed three principles th... G.C. Steinhardt |
17. Effect of Nitrogen Fertilizer Placement and Sources on No-till CornNo-tillage production of corn can lead to a number of savings for growers including costs of time, machinery, labor, and energy. However, savings of soil and water are perhaps the most important attributes of no-tillage production on the sloping, erosion-prone soils found in southern Illinois, Indiana, Missouri, and Kentucky. Producer acceptance of no-tillage has not been overwhelming. Prob- lems in achieving acceptable stands, difficulties in adequately con- trolling pests of all types, especia... |
18. Effect of Residual Profile Nitrate on Corn Response to N Fertilization in WisconsinResearch in several Great Plains and Western states has shown that crop yield response to fertilizer N is closely related to the amounts of residual nitrate in soil profiles. Based on this work, nitrogen fertilizer recommendations in these low-rainfall areas are adjusted to reflect the contribution of residual nitrate to the total crop nitrogen requirement. Use of residual profile nitrate data in development of N fertilizer recommendations has received much less research attention in the higher ... |
19. FS Green Plan Lender's Review- Introducing Local Lenders to FS Green Plan Crop ProductionGeneral 1. Increase communications between local lending agency Objectives: personnel and member company staff. 2. Introduce the FS GREEN PLAN crop production program to lenders. Familarize them with what FS has to offer their farmer cl ients. 3. Show lenders how FS GREEN PLAN programs recommend optimum production inputs to maximize crop profits for farmers. 4. Emphasize the availability of economic and net income projections to the farmer and his banker through use of the GREEN PLAN program. 5.... |
20. High Yield Corn ResearchThe objective of this study was to evaluate four corn hybrids at 15 and 30 inch row spacing and at plant densities of 28,000 and 34,000 plants per acre. The irrigated study was conducted at East Lansing on a Metea loamy sand soil. The 15 inch row spacing was obtained by back-planting in between 30 inch rows. Other cultural and management inputs are described at the bottom of Table 1. The first obviously noticeable difference in 1984 was the uneven stand in the 15 inch row spacing particularly fo... |
21. Influence of Phosphorus and Potassium Fertilization on Alfalfa Yields Under Intensive HarvestIn the northern part of the North Central (NC) states cutting management schedule and adequate fertilizer are important factors in maintaining alfalfa stands. Recent work in Minnesota by Sheaffer indicates that fall cutting poses some risks to lon-term stand persistance but should be considered as a management alternative to allow greater harvest flexibility. He further states that stand loss can be greatly reduced by high levels of fertilizer (particularly potassium). The study I am reporting o... |
22. Managing UAN Solutions in No-tillage CornStudies in many states over the past several years have indicated some type of inefficiency associated with broacasting N (nitrogen) as UAN (urea-anmnium nitrate) solution in no-tillage corn production situa- tions. Broadcasting UAN has often given lower yields when ccmpared to injected anhydrous amnonia or broadcast amnonium nitrate. Several theories have been proposed to account for this inefficiency, including volatilization of the urea canponent of the UAN, inmobilization of N during breakdo... |
23. P and K Fertilizer on Bottomland SoilsP and K Fertility on Bottomland Soils 1 William 0. Thom 2 Most of the bottomland soils of western Kentucky are important areas for corn and soybean production. They consist of the Belknap, Karnak, Melvin, Sadler, Stendal and Waverly soil series that are somewhat poorl y to poorl y drained. A phosphorus and potassium study was initiated on the Belknap soil in Webster County. Soybeans and corn were alternated during the 4 year study. The P study consisted of 5 rates (0, 50, 100, 150 and 200 Ibs P ... |
24. Small Grain Response to Potassium and Chloride AdditionsStudies have been conducted over a three-year period to determine the frequency and the cause of small grain response to KC1 additions on high K soils. During the first two years responsiveness of hard red spring wheat, spring barley, and oats were compared at six locations in eastern South Dakota. Broadcast applications of 167 lbs/A of KC1 caused grain yield increases significant at the 0.05 probability level at four sites for wheat and two sites for barley while no oat yield increases were mea... |
25. Some Effects of Soil Compaction on Root GrowthRoot growth and nutrient uptake are obviously related, and yet not well unders tood under field conditions . An oversimplified premise is that plant roots must grow to the site in the soil where the nutrients are retained, or that the nutrient must move to the absorbing root sur-face (or both). Relationships developed under well controlled uniform laboratory conditions of ten do not extrapolate to field conditions. In this respect, progress is often hindered by the fact that root growth measurem... |
26. Soybean Chlorosis Management ProgramChlorosis in soybeans is a problem wherever soybeans are grown on high pH soils. In Nebraska, most of the soybeans are grown in the southeastern half of the state. Here the upland soils are neutral to moderately acid; however, many of the river valley soils are alkaline. Thus, chlorosis is a problem in the Platte and Elkhorn River Valleys and to a lesser extent, in the Republican and Loup River Valleys. Not all soils in the river valleys are prone to chlorosis OF soybeans even though many are al... |
27. Tolerance to Low pH- Soluable Aluminum by Winter Wheat Grown in KansasThe majority of Kansas soils are relatively young ic terms of geologic development. Low pHs and the need for liming are not common in other than the eastern third of Kansas. In South Central Kansas, isolated very low pK's have been reported in fields predo~inantly cropped to continuous wheat since the late 1970s. However, in the past three to four years, an increasing number of low pH soils have been reported. A summary of the soil test results from the KSU Soil Testing Lab by year shows a dram... |
28. Ammonium Thiosulfate as a Urease Inhibitor- A suggested MechanismA great deal of interest, ard sca~ controversy, has been generaw by my observations (Goos, 1985a; Goos, 1985b; Fairlie and Goos, 1986) that ammonium thiosulfate (ATS, 12-0-0-265) can inhibit soil urease activity when mixed with fertilizers such as urea-ammonium nitrate (UAN) . Preliminary field research (Gascho and Burton, 1987; Fox and Piekielek, 1987; Lamond et al. 1986) has shown some increase in crop yields or N uptah by adding ATS to surface-applied UAN. However, the use of ATS as a urease ... |
29. Can we Afford Not to Ridge Till?A typical farmer response to ridge till is that it is just another method of tillage. My contention is that it is much, much more than that. In my career in this I have had three cbjectives. One is to attapt to create as much balance between famkq ad the enviroment as possible. ?he second is to rrake farming profitable. The third is to make farming easier and fun. I believe with the proper approaches in regards to fertility, chemicals and water management along with the ridge till technique the... |
30. Compaction - K Fertility Interactions in Corn ProductionSoil compaction is recognized as a significant factor affecting yield in crop production today. The pressure to produce crops profitably has often led gruwers to farm greater acreages, with larger equipment under soil conditions which favor compaction. Effects of compaction are not limited to the surface lay- of a soil but often may be apparent cut much of the root zone. With the interest in soil compaction and its effects on crop growth, a research project was initiated to accomplish the fol lo... |
31. Corn Stem Nitrate N Content-Grain Yield Relationships and Their use as a Basis for Sidedress N Rate RecommendationsThe objectives of this study were to confirm the relationship between nitrate nitrogen (NO3-N) content of basal corn steras and grain yield in Iowa, to establish crltical levels of stem NO3-N content for dtaining various levels of mximum yield, and to perform preliminary calibration of yield responses to sidedressed nitrogen (N) at various levels of st-Rm NO3-N content. Six sites across Iowa with a wide range of physical and environmental conditions were selected. N fertilizer was applied prepla... |
32. Do Hybrids Differ in Response to Differential Levels of Nitrogen Fertilizer?In the absence of other limiting factors, maize yield increases with nitrogen fertilizer application to very high levels. In fact, researchers attempting to maximize maize production have reported a yield -rise at levels of N greater than 300 lbs/acre. Because there are many limiting factors in addition to nitrogen, nitrogen fertilizer must be mged to minimize costs and maximize response. In addition to mging the crup's proctuctivity, recent concerns about high levels of nitrates and other farm... |
33. Effect of Ammonia Knife Spacing on Corn YieldExperiments were conducted at DeKalb on a Drummer sicl, Dixon Springs on a Alford silt loam and Elwood on a Blaunt sicl to evaluate the effect of ammonia knife spacing at varying N rates and on different tillage systems on the yield of corn Nitrogen was awlied at 180 1bs N/acre at bath DeKalb and El& and at 210 lbs N/acre at Dixon Springs in the knife spacing by tillage study. In the rate by knife spacing by time of application study at DeKalb, the preplant nitrogen was placed under where the ro... |
34. Effect of Ammonium to Nitrate Rations of Fertilizers Applied at Various Times Throughout the Growing Season on Yield and Nitrogen Concentrationof CornA number of recent investigations have produced evidenm that the ionic form of N taken up by roots affects the growth of plants. While soil- plants generally take up rest of their N as nitrate, there is evidence that increasing the relative proportion of ammonium in the culture (or soil) solution can enhance growth and yield. Owing to difficulties in prevent* the rapid miaxbial conversion of ammonium to nitrate in soil, this response has nat been well demnstrated in a field situation. The object... |
35. Effect of Intensive Management Practices on Wheat Yields and ProfitabilityConsiderable interest in improving wheat yields and profitability has been shown throughout the U.S. over the past ten years. Much of this interest has resulted from the dramatic yield increases achieved by English producers during that time - an annual increase of 5.0 bushellacre per year (Figure 1). During that same time period, wheat producers in the U.S. have shown a much lower rate of increase in wheat yields - 1.02 bushellacre per year (Figure 2). Missouri growers have been no exception to... |
36. Effect of Three Tillage Systems on Soil Bulk Density and Porespace DistributionMany grain producers in Kentucky use a 3 crop in 2 year rotation of corn fol lowed by small grain-soybeans, and commonly no-ti1 1 the soybeans and corn in order to intensively use sloping land for continuous grain production. Because of the intensity of machinery traffic in this system, grtwxs. are concerned that continuw no-till management may cause compaction, and that such fields may need occasional primary tillage. In order to obtain information regarding this situation, we conducted a test ... |
37. The Growth of MEY in Spring Wheat CountryAny ag orientated news source looked at in recent weeks in North Dakota or western Minnesota has had some kind of a MEY related story. The MEY usually has been identified as 19naximum economic yield," but recently some use of I1most efficient yield" has been seen. Yes, spring wheat country has a new buzz acronym - MEY. How did such a buzz term for tbis amount of press/news coverage develop in the spring wheat region? The kickoff for MEY club deve1-t ocaured on November 25, 1986. Before that was ... |
38. Improved N Use Efficiency for Wheat in Southwest IndianaAbout one-third of the wheat acreage in Indiana is grown in southwest Indiana. During most years this area of Indiana receives exoessive precipitation during the late winter and spring gruwth period for wheat. This presents problems with losses of available soil nitrogen (N) through leaching and/or denitrification and law uptake of N by the crop even on fields which have been well-fertilized. These experiments were condtucted in 1986 and 1987 to evaluate fall, mid-winter and late-winter topdress... |
39. Influence of Soil Nitrate Nitrogen and Fertilizer Nitrogen on Wheat Grain Yield and ProteinWheat producers have recently shown a great deal of interest in grain protein levels. 'Ikis interest has developed prkily because of the relatively lqe protein premium available the last several years (Table 1). Nitrogen is a primary component of protein and needs to be added for most soils to produce high yielding, high protein wheat. The objectives of this study were to detennhe the effects of soil nitrate nitrogen and fertilizer nitrogen on wheat grain yields and protein levels. ... |
40. Interaction of Potassium Fertilization and Row Width for SoybeansIn the past several years the row width of soybeans has decreased substantially. As row width decreases the amount of soil between rows for soybean roots to explore and from which to extract nutrients has decreased. Also many acres in the Midwest have little or no fertilizer added in the soybean year but rely on residual nutrients left from the previous crop. In this study the effect of row width and method of potassium fertilization for soybeans was investigated. ... |
41. Nitrogen Management for no-till Grain SorghumField experiments evaluating the effects of nitrogen management for no-till dryland grain sorghum were coacted in 1985 and 1986. Nitrogen rates (0, 50, 100 lbs N/A and placement methods for urea ammonium nitrate solution (UAN) have been evaluated in eastern Kansas. Placement methods have included surface broadcast, surface banded, pressure injected, and knifed. Results to date shm that nitrogen consistently increases yields and tissue and grain N contents, and that method of UAN placement produc... |
42. No-till Corn Response to N Fertilizer Sources and Placement Methods- A Summary of Southern Illinois ResultsExperiments were conducted in southern Illinois from 1984-1986 to evaluate the placement efficiency of several N fertilizers used in no-till corn production. Such information has become of meaningful importance as producers strive to obtain the greatest possible returns from their N fertilizer investment and to obtain yields and a level of profitability equal to that of more conventionally produced corn. Also, in the near future, no-tillage will become an important tool for many farmers in south... |
43. Optimum N Rates for Corn Production as Influenced by Crop RotataionFertilizer N efficiency in corn production has become a'hot' research topic in the 1980's. Increased concerns of nitrate-N entering the groundwater and the potential for improving the profitability of corn producers are the impetus for fine-tuning fertilizer N recarmnendations. Crop production factors such as improved diagnostic techniques, full utilization of symbiotic N fixation, and crop rotation have been gaining widespread research support throughout the United States. The adoption of crop ... |
44. Predicting Fertilizer Nitrogen Requirements for Corn in OntarioThe nitrogen fertilizer requirement of a crop under field conditions is influenced by numeraus factors including soil, climate and managanent variables. Most of these factors are very difficult, if not impossible to predict in advance. The major factors influencing nitrogen fertilizer nquhment are (Gch and Haynes, 1986); 1. the requirement of the crop for N as determined by its yield (or yield patential) , 2. the availability of fertilizer N or the fertilizer use - efficiency, and 3. the amount ... |
45. Preplant vs. Weekly Applications of N-P-K FertilizersMany studies have compared time of fertilizer application to corn, but few have looked at weekly applications of complete N-P-K fertilizers. Often only one nutrient is looked at individually making sure that the other nutrients of concern are adequately supplied. In some instances the ratio between the nutrient in question and other nutrients may be greatly out of proportion, thus resulting in an imbalance ard less than maximum response. Is it possible to add N-P-K nutrients in a certain ratio o... |
46. Water Quality Issues and Activities in MinnesotaWithin the last few years there has been considerable public concern over the occunrence of nitrates (NO;) in bath ground and surface waters. ?his is especially significant since 50% of drinking water for the U.S. tames fm g-muthter supplies and this increases to 85% in the rural areas (CAST, 1985). The issue has at tirrres becaw emotioml and fingers have been pointed regarding the cause of nitrates in our water supply. Consequently, steps are being taken to establish the relationship between N... |
47. Water Quality Issues in NebraskaThe primary water quality issue in Nebraska at this the is related to groundwater as opposed to surface water. Groundwater provides irrigation for over 7 million acres of land in Nebraska and is the drinking water source for almost a1 1 of Nebraska's domestic and municipal water users. In rural areas groundwater provides about 85% of the drinking water (Cast, 1985). Numerous reports of groundwater contamination led to its emeqence as a major environmental issue for the 1980,s. Govenrment agenci... |
48. 1989 Agronomic Implications of the 1988 DroughtHistorical Perspective Grain marketing analysts have a rule of thumb that says, "A short crop has a long tail". From the agronomist's point of view, a similar statement could be made for the agronomic implications of the 1988 drought. And coming on the heals of several years of depressed prices, there are some psychological effects that must be considered in working out management plans for farmers for the 1989 growing season. Since the 1988 season broke all previous records for extent and durat... |
49. An Evaluation of Nitrogen Application Methods for Ridge-Planted CornRidge planting is a conservation tillage method receiving some attention in the Midwest at the present time. In this system the crop is planted atop a ridge which was formed by cultivation of the previous year's crop. There is generally no tillage performed between ridge building and the next year's planting. The system is similar to no-till in that large quantities of residue are often present on the soil surface in the spring, most being concentrated in the ridge furrows. Research initiated in... |
50. Credibility in Soil Testing- Analytical ResultsIn Illinois, soil testing to help farmers plan line and fertilizer programs are done by cumrnercial testing services. The Agronoiny Department, University of Illinois participates in the State Soil Testing Program in research and coordinating rules. Kecognizing that sources of error in the program may occur in FIELD SAMPLING, ANALYTICAL TESTING, INTERPRETATION OF TEST RESULTS, or FORUMLATION OF RECOMMENDATIONS this paper focuses on ANALYTICAL TESTING. Two quality assurarlce programs in ANALYTlC... |
51. Credibility of soil Testing- Results os the Iowa Task ForceSeveral factors led to the convening of the Iowa Soil Testing Task Force: (1) The Iowa legislature passed the 1987 Groundwater Protection Act; (2) The Big Spring study in northeast Iowa in a Karst topography region revealed presence of pesticides and nitrates in groundwater; (3) Public awareness of contaminants in public water supplies was enhanced by influential newspapers and other publications; (4) Influential publications did major stories on the results of soil test comparison studies of se... |
52. Cropping System Effects on Phosphorus Response of CornToday's corn producer performs less tillage than in the past and predictions indicate that even less will be done in the future. Changes in management practices involving different tillage and residue incorporation practices alter the dynamics of organic matter turnover in soil and may influence the supply of plant nutrients. To maximize efficiency, it is critical that information be available to guide fertilizer management adjustments for specific tillage and rotation systems. A tremendous amou... |
53. Effect of Climatic Variability on Grain YieldsThere are three cycles in climate and weather that affect the north central part of the United States. They are (1) a long term cycle of global temperature changes; (2) an 18.5 year wet and dry cycle; and (3) the El Ni�o cycle. ... |
54. Effect of Application N timing and Plant Growth Regulator use in WheatWinter wheat is an important cash crop grown in the Midwestern states. However, progress in yield advancement has been slow compared to advances in other major wheat producing regions, notably Euro~e. This has lead to a competitive disadvantage of USA-produced wheat on the world market. In an effort to enhance wheat productivity and profitability a series of experiments were established in the fall of 1985 to assess the impact of more intensified management practices including the use of multipl... |
55. Effect of Nitrogen Rate and time of Application on Mefluidide Treated Smooth BromeLivestock producers who graze beef cattle or dairy animals usually have an abundance of pasture during spring when cool-season grasses grow rapidly. As hot, summer weather arrives, cool-season grasses cease vegetative growth and produce seed. Forage quality decreases as the grasses become dormant. Without alternative pastures or forages, cool season pastures become over-grazed and cattle performance is reduced. Using pastures composed of warm-season grasses that produce maximum dry matter during... |
56. Effect of Time of N fertilizer Application on Corn Grain Yield in IowaThe current concern about the impact of nitrogen (N) fertilizer use on the environment has caused a shift in the thinking about N management. Crop producers are interested in techniques (application methods) that will maximize the amount of N fertilizer harvested in the crop, and conversely minimize the amount remaining in the soil after harvest. Split applications or sidedress applications are common approaches currently being studied as a way to increase the efficiency of N fertilizer manageme... |
57. Effects of Chloride Rates and Sources on Winter Wheat in KansasOn wheat, and some other cereal grains, chloride has been reported to have an effect on plant diseases, either suppressing the disease organism or causing the plant to be able to withstand infection. It is hypothesized that yield increases are due to these effects. Researchers from several states have been able to show yield increases from chloride containing fertilizers. The most common source is potassium chloride, KC1. In many cases, soil test potassium levels are high, and most soil test re... |
58. Environmental Sulfur Sources as Inputs for Predicting Sulfur NeedsCrop responses to sulfur fertilization have been damstrated in mt states in the midwest, but the frequency of these responses is relatively lm. Sulfur deficiencies are usually confined to areas where one or mre of the follcrwing conditions exist: (1) Sandy or shallow soils; (2) Low soil organic matter content; (3) No recent manure applications; (4) Low atmospheric sulfur deposition; (5) High crop sulfur requirement. Although diagnostic tests to predict crop response to applied sulfur are an cbvi... |
59. High Yield Wheat Management StudiesInterest in high yield wheat management (i.e. intensive wheat management) has increased in Kentucky during the last few years. This interest has been created because of the improved yield potential of newer soft red winter wheat varieties, high yields obtained in inten- sive wheat management research in other states, and the high yields being obtained in Europe with their intensive management inputs. In several of the European countries, average winter wheat yields of 70 bu/acre or higher are co... |
60. Influence of Tillage and Placement on the Location of Phosphorus in the Root ZoneIn recent years, the ridge-till planting operation and the use of the chisel plow have developed into the most widely accepted planting systems for conservation tillage in Minnesota. While there is opportunity to incorporate plant nutrients in the chisel plow system, previous studies have shown that this incorporation is shallow when compared to the moldboard plow system. The ridge-till system, on the other hand, offers only limited possibilities for fertilizer incorporation. Typical broadcast a... |
61. Intensive Wheat Managent in the Corn BeltIntensive wheat management (ICX) is based on European cropping systems including narrow row spacing, precise seeding rates, multiple nitrogen (N) fertilizer application, fungicide application for disease control, and plant growth regulator (PGR) application for lodging control. Components of this cropping system were compared to current recommended management (CRM) practices with 12 varieties during 1986-87. The purpose for the experiment was to determine the responsiveness of soft winter wheat ... |
62. Nitrogen Fertilizer Requirements for No-till cornConservation tillage is associated with higher surface crop residue levels, larger more stable soil aggregates, and generally higher surface soil water contents compared to conventional tillage. The changes in residue management and overall soil water regime under conservation tillage may result in different spatial distributions (laterally and with depth) of nutrients. In general, nitrogen fertilizer applied as broadcast urea is not recommended for no-till systems because of the possibility of ... |
63. Perspective on Sustainable Agriculture- Sustaining Agribusiness in a Changing Rural EnvironmentAgriculture is an evolving industry -- it responds to market forces, tc improvements in technology, to government programs. LlJe also see changes as 3 result of new technologies, improved information about how to efficiently raise crops and livestock, and more integration with other sectors of society. In agriculture, as in arty business, to stand still is to fall behind the rest of the industry. !!le nnoed to be ready to adapt to change, to face ned rl-zli- ties, and even to initiate cnange in ... |
64. Probability of Success for Practices to Minimize Water Quality ProblemsI would like to spend my time this morning reviewing with you some of the practices and appraoches research has suggested as being useful in controlling quality of both surface water and groundwater. Given the limited time available, I will highlight only a few of the study findings, and confine my remarks primarily to the problems of nitrogen pollution of groundwater and phosphorus contamination of surface waters. This limited review is prompted more by what I perceive to be the major interests... |
65. Quantitative Risk AssessmentThank you for giving me the opportunity to speak to you today about carcinogens in drinking water and water quality standards. In the United States today, many if not most public water supplies contain chemicals that cause cancer in animals when, in laboratory tests, the animals are exposed to high levels of the chemical. Elost of these chemicals are man-made, but there are exceptions, such as the chlorinated methanes and, probably, related compounds. These chemicals are the byproducts of chlori... |
66. Soil Nitrate Testing- A Guide for Adjusting Michigan Nitrogen Recommendations for CornPrevious attempts to use soil nitrate tests in Michigan for adjusting N fertilizer recommendations for corn have been less than satisfactory. Soil tests were typically performed on fall or spring samples taken weeks or months prior to planting. The use of residual nitrate to adjust N fertilizer recommendations in the semi humid regions of the U. S. has never been considered very re1 iable because of the large fluctuation in soil nitrate from the time of sampling to the time of maximum uptake. So... |
67. Soybean Response to Potassium Rates and PlacementSoils of northeast Missouri in heavy soybean producing counties have generally become depleted of available potassium. Reason for depletion can largely be pointed to soybean production and a general perception that soybeans do not respond to direct fertilizer application. With a significant portion of the soybean acres in east and northeast Missouri being tenant farmed, efficiency and utilization of direct fertilizer application by the current crop is even more important to the grower. Band appl... |
68. Sustainable Agriculture- A PerspectiveThere is little evidence tos uggest that agriculture as practices in a variety of ways is not sustainable. We think of sustainable agriculture as a management system that uses inputs ... both those available as natural resources on the farm and those purchases externally ... in the most eficient manner possible to obain productivity and profitabilty from a farming operations, while minizing advers effects on the environment. Several groups have published materials suggesting techniques that shou... |
69. The Components of Sustainable AgricultureSustainable agriculture has become a rallying phrase for many concerned about agricultural profitability and environmental quality in the rural sector. Advocates of sustainable agriculture seem to be convinced that the policies and structure of the agricultural industry are responsible for increasing environmental problems, low farm profitability, declining farm numbers, and reduced quality of life in rural America. The agricultural popular press has published numerous stories about those concer... |
70. Use of Near infrared-NIR- Reflecctance for Improving Nitrogen Management in Spring WheatAdvancements in agricultural technology are providing both producers and researchers with improved tools for farm management d ec is ion making . Reduced profit margins are requiring farm managers to use these advanced tools to optimize input management in order to improve prof it levels. Fertilizer nitrogen (N) is a major input foi spring wheat in the Great Plains. Each year, many farmers fertilize spring wheat with nitrogen to improve seedling vigor and plant developmenl. Nitrogen is a major n... |
71. Yield and N Concentraions of Corn with Different N Sources Applied at Different timesA number of recent investigations have produced evidence that the ionic form of N taken up by roots affects the growth of plants. While soil- grown plants generally take up most of their N as nitrate, there is evidence that increasing the relative proportion of ammonium in the culture (or soil) solution can enhance growth and yield. Owing to difficulties in preventing the rapid microbial conversion of ammonium to nitrate in soil, this response has not been well demonstrated in a field situation... |
72. Combining Nitrification Inhibitor TechnologiesTechniques exist for the partial control of nitrification, but few studies have determined the effectiveness of combining more than one technique. A series of experiments compared the nitrification rate of urea granules as influenced by granule size (0.01, 0.1, and 1.0 g/pellet) and dicyandiamide (DCD) addition (0, 1, 2, 5, and 10% of N) . A second series of experiments measured the interactive effects of DCD and ammonium thiosulfate (ATS) on nitrification of liquid fertilizers. Both experiments... |
73. DAP vs MAP Manufacturing/Marketing ImplicationsOver the past several years, discussions on the suitability of monoammonium phosphate (MAP) and diammonium phosphate (DAP) as P sources for crop production have been common. In addition to agronomic principles, these discussions have often focused on what the future holds on the availability of these two materials in the marketplace. This discussion will deal with manufacturing and marketing influences on future availability/use, while agronomic comparisons will be made elsewhere. To some, phosp... |
74. Effect of Date of Planting on Method of P Performance for Winter WheatSeed and knifed P (dual placement) have usually performed similarly on winter wheat (Triticum aestiviuum L.), but in some years seed applications have been found to be superior to knifed P. Three winter wheat experiments were established on low available P soils in southeast Nebraska to study the effect of date seeding on seed and knifed P (dual placement) performance. Three rates of P (11, 22, and 33 kg P ha-') were seed and knife applied on three seeding dates in 1987. Data indicated that the ... |
75. Fertilizer use in the Future- A University PerspectiveOver the last few years, several agrodc, economic, political, environmental and sociological trends have begun to eruerge which will significantly affect fertilizer use in the next decade and perhaps beyond. The wide-spread use of fertilizers is a relatively recent developmt. Over the past 40 years, farmers repeatedly saw the benefits of fertilizer applications and developed a faith in their need. Hwever, the 1990's are not the 1950's. As point& out by Dean L. M. Walsh in a recent paper in Deale... |
76. Integrated Farm Management Demonstration Program in IowaThe Integrated Farm Management (IFM) Demonstration Program was established by the landmark 1987 Iowa Groundwater Protection Act. The five-year program, funded through 1992, is a cooperative effort involving various state agencies, Iowa State University and Iowa farmers. The program coordinators, many of whom are Iowa State Extension Service staff and scientists, work with farmers to help them implement best available technology that protects the environment and conserves energy. The goal of the ... |
77. Managing Field Soil Fertility VariationsFertilizer and crop production inputs are most often applied as a single blanket application rate across an entire field. Yet variations in field conditions including soil characteristics and measured crop yield are known to exist and often in a systematic, fashion. Grid soil sampling for fertility variations, plant analyses, and color photography were found to be most useful tools for assessing manageable field variations. Increased profit and environmentally sound improvements in fertilizer us... |
78. Nitrate Soil Testing Correlation and Calibration Eastern Corn BeltCurrent economic and environmental concerns have increased the interest in developing methods to help manage nitrogen (N) fertilizers as efficiently as possible. There is a concern that fertilizer N that remains in the soil following harvest may be leaching below the root zone of crops and eventually ending up in groundwater. Agronomists throughout the corn belt are actively evaluating methods to manage N fertilizer as efficiently as possible.... |
79. Nitrate Testing ClinicsThirty-eight nitrate testing clinics were held in 36 Michigan counties in the spring of 1989. A mobile testing van was equipped for nitrate analysis of soil and water samples. Over 2,200 soil samples and 1500 water samples were analyzed for nitrate N using the nitrate ion-specific electrode. More than 50 percent of the soil samples . contained less than 30 lb of nitrate N in the surface two feet. Only 35 percent of the 1,100 fields were given a nitrogen credit based on the residual nitrate test.... |
80. Nitrogen Management for Cool Season Grass ProductionStudies were initiated in 1985 on established smooth bromegrass and tall fescue to evaluate urea granule size effects on forage production and quality. Other work, evaluating N source by previous source effects and UAN placement methods and the addition of ATS, was conducted on established smooth bromegrass. Nitroger1 rates were also evaluated in all these studies, and the addition of N significantly increased forage yields and N concentrations in each study. Use of large (1.0g) urea granules pr... |
81. Nitrogen Management for Winter Wheat in MissouriEight site years of data have been collected to evaluate nitrogen rate and timing for intensively managed winter wheat in Missouri. Variables have included rates up 160 lbs N per acre applied as all fall, all spring, or split in a fall and spring or fall plus two spring applications. Results have pointed to the split applications of rates at 80 to 120 lbs N per acre as providing greatest consistency and economic return to the grower. Maximum yield has generally been obtained with the 3 way split... |
82. Nitrogen Soil Test for Corn in OntarioIt is generally believed that for high yielding crops such as corn. the N requirements are much larger than variations in the N supplying capacity of soil. In Ontario, fertilizer N recommendations are based on the requirements of the crop and, for some crops, the expected yield goal. Nitrogen credits are given for past management such as manure application and legumes in rotation. The credits are deducted from the economic rate of N. In a recent analysis of all existing fertilizer N crop respon... |
83. Nitrogen Source Affects Manganese Nutrition of No Till CornA study evaluating response of no-till continuous corn to different rates of N as injected anhydrous ammonia and broadcasted urea-ammonium nitrate solution (UAN) was conducted on a Canfield silt loam near Wooster, Ohio. Repeated use of anhydrous ammonia on this naturally acid soil resulted in relatively large concentrations of Mn (often > 200 ug/g) in corn plant ear leaves at silking. Ear leaf Mn concentrations were less when UAN was used. For both N source treatments, ear leaf Mn concentrations... |
84. Nitrogen Test Development Soil N Levels in 1989The developnent of a N test that can be used for fertilizer recamrendations of corn in the eastern areas of Minnesota is needed for environmental and econcmic reasons. A multi-site project was initiated in 1989 to extensively examine soil sampling time and depth as well as N forms in the soil. This will then enable statistical models to be develaped using one or mre of the variables. A subset of the entire project is reported--concentrating on the sites allowing the calibration of the soil N tes... |
85. Phosphorous Management for Wheat ProductionProfitable wheat production depends on many factors, including a sound phosphorus (P) management program. Except for sunlight and water, soil fertility generally represents the most limiting factor in crop yields. Even with perfect weather and climatic conditions, a farmer that does everything right except to meet the nutrient needs of the crop will never reach optimum yield potential. Water, N, and P are generally the dominant yield limiting factors for wheat in the United States. Potassium, S,... |
86. Residual Soil NO3 N Variability Sampling Interpretation and Effect on Corn YieldResidual nitrate-N (NO3-N) in the soil profile (crop root zone) is seldom uniformly distributed. There is lateral as well as vertical variability. Numerous factors influence variability. Some of them are: 1) any factor that influences water movement through the soil such as - soil texture, compacted zone, topography and water distribution under irrigation - 2) previous crop, 3) fertilizer history (organic and inorganic sources) and 4) sampling time - caused primarily by factors influencing miner... |
87. Response of No-till Corn to Urease Inhibitors and Placement of N SourcesN(n-buty1)thiophosphoric triamide (NBPT) and ammonium thiosulfate (ATS) were investigated as urease inhibitors when added to urea and urea-containing N sources and applied to no- ill corn. Significant - f yield increases, some in excess of 20 bu ac , were observed with NBPT treatment of the N fertilizers. Lack of a yield response from NBPT, when it occurred, was usually associated with a rain event of major proportions soon after fertilizer application. ATS showed considerably less promise as a ... |
88. The Effect of Tillage and Soil Test and Applied K on Corn and Soybean ProductionThe buildup-maintenance fertility concept for P and K has a strong theoretical basis, but much of the research from which it was derived was not designed to accurately determine the true maintenance requirement. Most of that research was confounded by an annual application at set rates irrespective of yield obtained. Experience in recent years has shown that on some soils the K soil test has not consistently accounted for past additions of fertilizer. In addition, applications equivalent to crop... |
89. The Nitrate Soil Test in South DakotaThe nitrate nitrogen soil test has been used for more than 15 years for making nitrogen fertilizer recommendations in South Dakota. Minimal leaching and denitrification due to a relatively dry climate has helped make this test a good predictor of nitrogen fertilizer needs. The test and nitrogen recommendation system is based on a two foot deep soil sample and a calibrated nitrogen requirement for common crops grown in South Dakota (Table 1). Extensive field plot data shows that the two foot deep... |
90. A Comparison of Point Injected and Knifed Phosphorus for Winter WheatThere are almost 2 million acres of winter wheat grown in South Dakota. Most is produced in the southwest part of the state on residual clay soils in a wheat fallow rotation with only limited, shallow sweep tillage. Very reduced tillage is necessary for wind and water erosion control, and water conservation on the long steep slopes. The continued use of shallow tillage on highly buffered, high pH soils has made broadcast phosphorus fertilizer inefficient in increasing wheat yields, even though p... |
91. Ammonium Thiosulfate Effects on Corn ProductionAmmonium thiosulfate ((NH,),S,O,, ATS) and urea-ammonium nitrate solution (UAN) were applied in different combinations to corn grown in five site-year studies to assess any effects of ATS on corn performance. Ammonium sulfate ((NH4),S04, AS) was included in three of these comparisons as an alternate sulfur (S) treatment. Adding ATS to UAN increased corn yield in one comparison, decreased it in another and had no effect on yield in others. Adding AS had no effect on corn yield. Neither S material... |
92. Banded Potassium for Ridge-till Planting SystemsThe ridge-till planting system is a proven tool for controlling soil erosion and providing maximum efficiency of water use by corn. The use of the ridge-till planting system in the northern Corn Belt has increased substantially in the past several years. Recently, however, potassium (K) deficiency symptoms have been reported in many fields. These observations have occurred even though soil test values for K have been in the high range. As the number of reports of K deficiencies increased, it was... |
93. Corn Yield Response to the Urease Inhibitor N-n-Butyl Thiophosphoric Triamide (NBPT) When Applied with UreaUrease inhibitors are applied to reduce ammonia volatilization and immobilization losses from surface-applied urea or urea-ammonium nitrate solutions (UAN). The urease inhibitor N-(n-buty1)thiophosphoric triamide (NBPT) was evaluated at rates of 0.25 to 1.0 % (w/w) in 78 U.S. trials conducted with corn (Zea mavs L.) during the period 1984 to 1989. When averaged over N rates for all locations and years, NBPT increased grain yields by 4.3 bu/acre when compared to similar rates of unamended urea. A... |
94. Effect of Alfalfa Stand Density or Cutting Management on Nitrogen Supplying CapacityEconomic, energy and environmental considerations are making the efficient use of nitrogen fertilizers increasingly important for Wisconsin crop producers. Excessive nitrogen applications cannot be tolerated environmentally due to the potential for N leaching to groundwater, or economically due to the relatively high cost of N fertilizers. The potential exists for many producers, farming in legume rotation, to unknowingly over-apply N by not fully applying credits for previously grown alfalfa. A... |
95. Effect of Irrigation and Nitrogen on Corn Yield and ProfitAn understanding of the interaction of various inputs on corn yield and profit is important in decision making for corn production. This study was conducted to evaluate 1) the effect of irrigation, hybrid, seeding rate and nitrogen rate on yield of corn and 2) the effect of these inputs on marginal return and cost per bushel for corn production. This study was conducted for three years at two 1 ocations on a Conover 1 oam and a Zi lwaukee clay soi 1 . The three years represented a normal rainfal... |
96. Establishing (and Differentiating) On-farm Research and Demonstration TrialsAs the 1990s begin, funding agencies are looking beyond the traditional definition of who does "research." While university, USDA and private industry have traditionally conducted research in the past, grassroot organizations, local agency personnel and individual farmers are now proposing and implementing research of various types. An overall trend seems to be for research experiments to be evaluated on farmersf fields. Some of this movement may be a political statement against traditional meth... |
97. Fertilizer Recommendations in the Eastern Corn BeltThe purpose of this paper is to discuss fertilizer recommendations for corn and soybeans made by three universities and by three private institutions in the Eastern Corn Belt. For lack of a better term, the six sources of recommendations will be referred as "labs", a commonly-used abbreviation for soil testing laboratories. This term does not accurately describe Countrymark which uses the results from other labs on which to base its recommendations. ABSTRACT Nitrogen (N), phosphorus (P) and pota... |
98. Improving Nitrogen Recommendations in NebraskaSoil nitrate tests offer a unique opportunity to fine tune our nitrogen management into the 90's. Nebraska has had a long history of research and extension programs using soil nitrate levels to modify fertilizer nitrogen recommendations. Because of our climatic regime nitrate tests work well across the whole state. We have a large data base on research plots that shows the tests are very effective. A large number of farmer demonstrations conducted over the last 10 years also show that the techno... |
99. Interpretation and Presentation of Research InformationCrop yields have increased over time as the knowledge base supporting crop production practices has increased. The educational process of transfer of information based on research bears a deep sense of responsibility. Selection of research results on which to base recommendations is a matter of judgement that can be enhanced by proper statistical analysis. Experimental objectives, experimental design, treatment selection, number and years of experiments, environments in which the experimentatio... |
100. Long Term Tillage and Fertility Effects in CornA long term study to evaluate tillage methods and fertilization practices on corn under monoculture was initiated in 1970. Effects on grain yields and soil property changes were evaluated over 20 growing seasons. Four tillages evaluated were continuous conventional, alter- nate till (2 years no-till: 1 year conventional till), continuous chisel till, and continuous no-till. The five fertilizer treatments evaluated were: control, 0-0-0; 175-0-0; 160-0-0 broadcast plus 15-80-120 row banded at plan... |
101. Manure ManagementNutrient management should be looked at as an integrated, continuous process. It starts with an assessment of the overall nutrient balance on the farm If this simple assessment indicates a nutrient imbalance, a more detailed assessment will indicate specific field imbalances that need to be considered in the manure management process. Once an assessment has been accomplished, management options for dealing with the situation can be explored. If there is an overall nutrient imbalance on the farm,... |
102. Nitrate Test Clinics in MichiganNitrate contamination of groundwater in Michigan is becoming an increasing public concern. Fertilizer N, animal manures and rural septic systems have been implicated as possible nonpoint sources of contamination. A state wide program of monitoring nitrate N in soil and well water was initiated. In the spring of 1989 and 1990, 74 nitrate testing clinics were conducted. Over 3,600 soil samples and 1,900 water samples were analyzed for nitrate N using the nitrate ion-specific electrode. More soil n... |
103. Nitrification of Banded Liquid FertilizersField studies were conducted in 1990 at three sites to compare the relative effectiveness of ammonium thiosulfate (ATS, 12-0-0- 26s) , dicyandiamide (DCD) , and nitrapyrin (NP, ' N-Serve 24E' ) as nitrification inhibitors in combination with banded urea-ammonium nitrate (UAN). Applications were banded prior to planting spring wheat, and soil samples taken 2, 4, and 8 weeks after application. ATS, DCD, and NP inhibited nitrification at all three sites. ATS inhibited nitrification at the 4 week sa... |
104. No-till Nitrogen Management Research in MissouriNo-till nitrogen management research on corn in Missouri has focused on the field response of N sources and placement. Results suggest consistent significant response to the use of a non-volatile N source when broadcast on the soil surface compared to N sources that contain urea and potentially can lose ammonia through volatilization. Knifed application of N in no-till has . consistently provided higher yields and N uptake compared to either surface band or broadcast application of potentially v... |
105. Sulfur Fertilization of Smooth BromegrassStudies were initiated in 1987-88 on established smooth bromegrass at two sites in eastern Kansas to evaluate the effects of sulfur fertilization on bromegrass forage production and quality. Sulfur rates (0, 15, 30 lb S/ac) and sources (ammonium sulfate and ammonium thiosulfate) were evaluated. The addition of sulfur consistently and, in most cases, significantly increased bromegrass forage yields and forage S concentrations. Sulfur had little effect on forage protein levels. Ammonium thiosulfa... |
106. The New Wisconsin Soil Test Recommendation ProgramThe modern Wisconsin soil testing program was originally developed in the early 1960's. It was revised rather thoroughly in 1970 and again in 1981. New research advances, additional correla- tion and calibration data, changes in user needs, and shifts in philosophical viewpoint make it necessary to periodically review the soil testing program and the recommendations that emanate from that program. The current revision is an attempt to incorporate additional research, eliminate certain inconsiste... |
107. Trends in Soil Test P and K in IowaThe Iowa State University Soil Testing Laboratory has provided soil test information to Iowa farmers since 1931 when Professor Firkins began the service for no charge. The predecessor of today's lab was initiated in February, 1946 (~ik~) . The lab's records provide us with valuable information on the trends in the plant nutrient status of Iowa's soils (Figure 1). During the period from 1960 to 1981, the consumption of nitrogen (N), phosphate (P), and potash (K) fertilizer materials rose from 7.5... |
108. Aglime for Corn and Soybean ProductionLiming acid agricultural soils has been a long-time proven practice to maintain/improve crop yields, particularly forage legumes, and to favorably affect soil chemical, biological and physical properties. Summaries of soil test results from the Iowa State University Soil Testing Laboratory for the past 35 years have shown a consistent 2 to 3 percent of soil samples with a soil pH below 5.5 and 14 to 16 percent with soil pH between 5.6 and 6.0. There has been an increasing percentage (from 21 to ... |
109. Assessing Crop Nitrogen Needs with Chlorophyll MetersTissue testing of corn leaves for nitrogen (N) concentration is not widely used because it is easier and perhaps more economical to apply sufficient fertilizer than to risk a yield reduction because of an N deficiency. Environmental concerns related to N fertilizer will require producers to improve N management practices to reduce the potential for nitrate leaching. Applying fertilizer N on an "As Needed" basis rather than using a "Lump Sum" approach has both environmental and economic implicati... |
110. Best Management Practices for Nitrogen in MinnesotaAtrention to nirrogen (N) nlanagemerzt and to rhe influence of N on ground- rvarer qzraliry was significanrly enhanced in Minnesota wirh the passage of the Conlprehensive Groundwater Protection Acr in 1989. That legislative act mandated the fonnarion of u Nirrogen Fertilizer Task Force whose duty was ro study the eflecrs and impacrs on water resources fro,n N fenilizer use so rhar besr management practice (BMPs), a fenilizer managenlenr plan, and N fem'l- izer use regulations could be developed... |
111. Economic Perspective on Variable Rate FertilizationSoils form a continuum across every farmer's field, constantly changing in both physical and chemical characteristics. Sometimes these changes are visible; sometimes they are completely masked to the eye. Variables such as organic matter, water-holding capacity, pH, and soil nutrient levels differ, and combined, they affect crop yield goals. In either case, these differences should result in different management practices, including fertilizer applications, being recommended for different soils ... |
112. Evaluation of Soil Profile NO3-N for Prediction of N Fertilizer RequirementsCurrent N recommendation systems based on yield goal with adjustment for previous legume crop or manure applications have worked well in many situations. In the example given in Table 1, multiplying the 8 year average yield times 1.2 lb N/bushel would result in a recommendation within 20 Ibs N/acre of the optimum in 6 of the 8 years. As expected, this system resulted in significant over recommendation in the 1988 and 1989 drought years. While these results provide confidence that the system wor... |
113. Foliar Fertilization of Soybeans in MissouriSoybeans may benefit from foliar fertilization during the reproductive phase of growth. Foliar fertilizers consisting of factorial combinations of boron, calcium, magnesium and phosphorus were applied to soybeans every other week for eight weeks beginning at flowering at three locations. The foliar fertilization treatment containing B+Mg (1.0 lb/acre B + 2.0 lb/acre Mg total) and split into four applications at Mt. Vernon and the Delta Center increased yields by 8 and 4 bulacre, respectively. Th... |
114. Ground Water Quality Research and Demonstration Projects in NebraskaTwo projects were initiated in Nebraska in 1990 to address concern with increasing levels of nitrate in ground water as part of USDA's Water Quality Initiative. The Nebraska Management Systems Evaluation Area (MSEA) Water Quality Project is a joint effort of USDA Agricultural Research Service (ARS) and University of Nebraska-Lincoln scientists. One phase of the project is investigating the direct impact of four management systems on ground water quality. Another phase of the project is evaluatin... |
115. Missouri Grid Soil Sampling ProjectA grid soil sampling project has been conducted over the past three years in S.E. htissouri for creating a database to provide for variable fertilizer application within fields. Results have shown widely varying soil test levels in excess of 100% variation for P and K. Gross returns to variable spreading of P and K are estimated using an expected soil test and nutrient response function. As may be anticipated, returns to variable fertilization application within a field are also highly variable... |
116. Nitrogen and Phosphorus Fertilization of Cool Season GrassStudies were initiated at two locations on cool season grass in central South Dakota to evaluate the effects of nitrogen and phosphorus on forage and seed yields. Nitrogen rates (0,30,60,90,120,1501b Nacre) and phosphorus rates (0,30,60,90,180 Ib P,Odacre) were applied to established crested or intermediate wheatgrass once and harvested for either two or three years depending on location. Nitrogen increased dry matter yield by 48 and 62% at the two locations and seed yield by 166 percent. Phosph... |
117. North Central Regional Nitrate Soil Testing ProjectAlthough preplant soil nitrate (NO -N) tests have a long history of 3 successful use in semi-arid regions of the Western and Great Plains region of the United States (Hergert, 1987), soil NO -N testing in humid 3 regions is currently receiving substantial research attention. One of the most promising approaches to KO testing in the higher rainfall areas 3 of the Midwest and Eastern states is use of the pre-sidedress soil NO test (PSNT) (Magdoff et al., 1984). Research conducted in the humid 3 re... |
118. On-Farm Nitrogen Fertilizer DemonstrationsThe Magdoff Pre-Sidedress Nitrate Test (PSNT) has been successful 1y used in the Northeast and humid parts of Midwest to improve N fertilizer recommendations. A modified version of the Magdoff PSNT was evaluated in 1989 and 1990 in Michigan. Fifty-three large scale on-farm corn N demonstrations were carried out. Two rates of N (a reduced rate and a high rate) were rep1 icated 3 to 6 times in each field. Forty-six sites showed no significant (p=.05) yield reduction due to the reduce N rate. Forty... |
119. Overview of Soil Fertility Research in Ontario, 1991The major areas of focus in soil fertility research at the Department of Land Resource Science, University of Guelph over the past year have concerned increased nuhent use efficiency and environmental impact. These studies have examined the development of nitrogen soil test for corn, nitrate movement to groundwater, the fate of manure N, the placement of phosphorus fertilizer and the role of VA mycorrhizae in plant phosphorus numtion. The following is a summary of the projects being conducted in... |
120. Phosphorus Placement and Tillage Effects on Corn and Soil P LevelsIncreasing crop production costs have producers scrambling to gain the greatest efficiency possible from added fertilizers. A field study was conducted at two locations in southern Illinois is assess the effect of phosphorus (P) rates and placement methods on yield and P uptake by corn under no-till (NT) and conventional (chisel and disk) tillage (CT) systems. Phosphorus rates consisted of 0, 20, and 40 pounds P205/Ac with placement methods of surface broadcast, dribble and 2x2 at planting. Afte... |
121. Predicting Subsoil Nitrate Content from Surface MeasurementsPreplant soil profile nitrate (NO,-N) tests are effective for I predicting corn (Zea mays L.) responsk to applied N. The difficulty of obtaining profile soil samples is one of the main obstacles to more extensive use of preplant tests. One approach to overcoming this barrier is to develop and use models to predict subsoil NO -N contents 3 from surface soil NO -N measurements. Data from 2295 routlne field 3 samples submitted to the University of Wisconsin Soil and Plant Analysis Laboratory from 1... |
122. Reducing the Severity of Phyophthora Root Rot Damage in Soybeans with Selected Management OptionsPhytophthora root rot of soybeans (PRR) is a major concern for soybean growers in south-central and southeastern Minnesota, where it can be responsible for major yield reductions. In these regions, PRR is generally a serious problem when soybeans are grown on poorly drained soils and/or there is a moderate amount of rainfall within 2 to 3 days of planting. Previous research has shown that PRR causes a reduction in the number of harvestable plants per acre and this is the major contributing facto... |
123. Starter N and P Effects on Early Maturing Corn Planted EarlyShort-season corn planted early is a water-use management option being investigated in the central plains states. This study was conducted in an attempt to determine optimum starter N and P fertilizer rates and to compare subsurface banded versus surface applications of P for short-season corn planted early. Each location had a 3x3 factorial arrangement of N and P (0, 20 and 40 lbs N or P205/acre) placed 2 inches below and beside the seed as well as one or both application methods of surface bro... |
124. Studies of Agricultural Effects on Groundwater Quality in KentuckySeveral small watersheds and tiled fields have been selected in Kentucky to assess the influence of agricultural practices on groundwater quality. Sites were selected to represent the dominant agricultural systems used in the most agriculturally important areas of the state. Within each study site, water samples from springs, wells, streams, or tile lines are being sampled monthly to monitor content of N03-N, atrazine. alachlor, and fecal bacteria. Although sampling will continue for at least an... |
125. The Soil Doctor- A Field TrialThe growing environmental concerns of the nation are causing some changes in production agriculture. One of the environmental areas receiving attention is NO,-N in the ground water. A number of universities and private companies have directed attention to this problem. The pre-sidedress nitrate test is the most common approach to reducing excess nitrogen application on corn in the humid eastern U.S. Several researchers have developed systems to use this test. Fields are sampled to a foot depth w... |
126. A Nitrogen Soil Test for CornIn the past decade, many states have started including a soil test when making N recommendations. In order for a soil N test to be useful, it must provide information that is not known or incorporated when making N recommendations without a test. If a test does not provide explainable, qunlltifiable infarmation. the tcs: !cses its usefghess. In Minnesota, a falllspring preplant N test has been used in the western tier of counties, which have lower rainfall than the rest of the state, for many ye... |
127. Alfalfa Responses to PotassiumThe potassium requirement of alfalfa is greater than that for any other nutrient. Potassium influences several systems within alfalfa plants including enzyme activity, carbohydrate production and transport, stornatal activity, photosynthesis through chlorophyll content and C02 exchange rate, and nitrogen fixation. Excellent reviews on the role of K in physiological processes are provided in the most recent potassium monograph (Munson, 1985). Potassium also markedly influences alfalfa agronomical... |
128. An Overview of the Thompson/Baker Farming Systems StudyThere is a general lack of quantitative information, collected from field-scale studies, that can be used to assess long-term effects of alternative farming systems. The objective of an on-going study in central Iowa is to quantitatively evaluate several chemical, physical, biological, and economic parameters on the Richard Thompson (alternative) and Eugene Baker (conventional) farms. This project was initiated in 1989 on adjacent 32-ha tracts of land, that have Clarion loam, Nicollet loam, Cani... |
129. Assessing the Source of Groundwater Nitrates- And You Thought Good Wine Took TimeControversy continues with elevated groundwater nitrate concentrations being attributed to N fertilizer use. Current research defining best management practices in farming system K management seldom addresses the influence these practices have on groundwater. Why? The results of this Missouri research show that the influence of management on groundwater nitrates may last for decades. The study provides support for time requirements when assessing farming system impact on groundwater quality. ... |
130. Certified Crop Adviser (CCA) ProgramThe Certified Crop Adviser (CCA) Program is being developed under the auspices of the American Society of Agronomy (ASA). The ad hoc steering committee is comprised of industry and university agronomists, state dealer associations, independent crop consultants, several organizations (including T.F.1, P.P.I., ARA, TVA) and ASA staff. This is a broad group representing wide geographic parts of the U.S., and has also included USDA officials, representing SCS and Extension. The purpose of the CCA pr... |
131. Economic Optimum Rates of N for Corn Production in IowaProper nitronen (N) fertilizer is essential if crop producers are to maximize profits and minimize environmental contamination. A study to determine 'economic optimum N fertilizer rates was conducted in Iowa from-1987 to 1991. The results show that Iowa crop producers over-applied N during those years primarily due to not considering residual N in the soil. This was especially true following the drought year of 1988.... |
132. Effects of Residue Density Levels on the Response of No-till Corn to N Fertilizers and InhibitorsExperiments were conducted from 1989-91 at tho southern Illinois locatio~ls (~elle\?ille and Car*bcrndale) to evaluate the effect of residue levels un the perfor-mance of N fertilizers, urease inhibitors, and placenient on the response of no-till conl. Levels of 0, 50, 100, and 200 percent of existing (pre-plant) amounts were established in the crop residues of previous corn. Kitrogen fertilizers were urea-ammonium nitrate (UAN) solution (dribble, injection. and split-applied) and urea (broadcas... |
133. Evaluation of Three N Recommendation Systems for Corn Yield and Residual Soil NitrateProper N application rates are required for continued economic and environmental viability of U.S. agriculture. Application at rates below that required for economic optimum will place U.S. farmers at a competitive disadvantage in the world market. On the other hand, excessive rates of N fertilizers may result in contamination of ground water. ... |
134. Importance of Subsoil PotassiumRecent information has emphasized the importance of nutrient distribution by depth in soils. Information from across the Cotton Belt in the U.S. has demonstrated that cotton yields have been affected by accumulation of potassium (K) near the soil surface with subsequent depletion of subsoil K. This condition combined with changes in K demand by new, high-yielding cotton varieties has led to a change in cotton K deficiency symptoms and delayed diagnosis of the actual problem. Recent studies have ... |
135. In-Field Determination of Anhydrous Ammonia Applicator Accuracy in NebraskaLiquid and dry fertilizer applicators have been studied for their application patterns and precision. However, anhydrous ammonia (AA) applicators are generally considered less accurate. Due to the difficulty of calibration, actual application errors have not been documented. In order determine if AA applicators were delivering the intended application rate, a standard AA nurse tank was fitted with load cells, temperature, pressure, travel speed and travel distance sensors. Initial data from 55 f... |
136. In Search of EAN of Spring WheatMany spring wheat varieties respond reliably to enhanced ammoniunl nutrition (EAN) in the greenhouse. Three field studies were established in 1992 to determine if similar responses could be obtained in the field. Butte 86 spring wheat was fertilized (100 Ib N/A) with calcium nitrate, urea, urea + DCD, forestry-grade (0.1 g) urea pellets and forestry-grade urea pellets + DCD. The goal was to provide wheat with a large range of a1nmonium:nitrate ratios and to determine the effect 011 wheat develop... |
137. Influence of Phosphorus Soil Test Level on the Probabaility of Corn Yield ResponseData from a long term residual phosphorus study was analyzed to determine the probability of a corn yield response at low, medium, high and very high soil test levels. Analysis of 55 rate-site years showed a corn yield increase 59, 22, 43 and 17% of the time respectively for low, medium, high and very high soil test categories. The very high soil test category is defined as a Bray P soil test of greater than 20 ppm. The results suggest that the current South Dakota State University recommendatio... |
138. Long-Term Alfalfa Study With K RatesA long-term potassium rate study was conducted on a Maury silt loam as part of the soil test calibration program to develop data for more soils in Kentucky. Beginning soil test K levels were established with initial applications of either 0, 150 or 300 lb of K20 per acre. Annual applications of 0, 120, 240 and 360 lb of K20 per acre were applied about 1 month before fall freezedown. Results indicated (1) there were significant yield responses to annual applications after the first year; (2) the ... |
139. Long Term Phosphorus Research on Corn and Grain SorghumPhosphorus fertilizer is needed for optimum production and economic returns from irrigated corn and grain sorghuni in western Kansas. A long term study shows that the yield benefit from P increases over time from no yield difference initially to over 100 butacre higher corn yields after 30 years. Without fertilizer P, soil P levels declined from 17 pprn Bray- 1 P to less than 10 pprn within five years, where they stabilized for both corn and sorghurn. The addition of fertilizer P at 40 Ib P205la... |
140. Nitrogen Management Systems for Ridge-tilled Corn ProductionThe use of conservation tillage methods, including ridge- tillage, increases crop residue cover which can lead to loss of urea-based fertilizers applied broadcast. ~ield tests were conducted during 1987-1991 at the ~rrigation ~xperiment Field, located near Scandia, Kansas, on a Crete silt loam soil (fine, montmorillionitic, mesic, Panchic, Arguistoll). Treatments included anhydrous ammonia (AA) applied preplant knife-injected; 28% urea-ammonium nitrate solution (UAN) applied preplant knife- inje... |
141. Phosphorus Management on Extremely Acid Soils in South Central KansasResearch was conducted to evaluate the effectiveness of phosphate fertilizer in reducing the toxicity of soluble aluminum (Al) on very acidic soil for production of winter wheat. Banded P fertilizer increased wheat grain yields significantly with the response being greater on unlimed compared to lime conditions. Based on the findings of this research coupled with Oklahoma State University research, banded P is an alternative to liming for wheat production on extremely acidic soils with consider... |
142. Potassium RecommendationsMost soils have relatively large contents of total K but relatively small amounts of plant- available K+. Potassium is found as a component of several minerals that release it to soluble and exchangeable forms by weathering at greatly differing rates. These forms are shown in the adjacent figure. Some of these minerals also have the capacity to reabsorb (fix) added K+ back into their structures in nonexchangeable form. Even the exchangeable K+ is bonded with different strengths depending on the ... |
143. Preplant Soil Nitrogen Test for CornSoil ammonium N and nitrate N were measured at the pre-plant and sidedress stages on 59 Michigan fields in 1992. Total inorganic soil N (ammonium N plus nitrate N) at pre-plant stage averaged to 12.6 ppm, about 50% of which was present in the nitrate form and 50% in the ammonium form. Total inorganic N at sidedress stage was 18.9 ppm, of which the nitrate N component was 12.2 ppm. The NH JNO, ratio decreased from 1.06 at prep1 ant stage to 0.54 at sidedress stage. Multiple correlation analysis ... |
144. Response of Ridge-till Corn to Potash FertilizationIn recent years there has been an increased interest in growing corn with either ridge-till or no-till planting systens. This interest has been stimulated by concern for conservation compliance, farm profitability and the environment. Many problems have surfaced as these tillage systems are adopted by more and more farmers. The appearance of potassiu,~ deficiency symptoms has been a major concern for those who grow corn and soybeans with these tillage systems for the past four or five years. For... |
145. Role of Land Tenure-Other Factors in Soil P InterpretationsSoil test interpretation should recognize the residual value of applied PI the inherent limitations of soil P tests, and utilize an approach that can be easily personalized at the local level. These criteria were used to develop an interpretation approach utilizing a computer spreadsheet to estimate the optimum soil test level for an individual grower. The spreadsheet requires the following inputs: a calibration curve, acceptable marginal return, interest rate, land tenure, soil test buffer pote... |
146. Summary of P Fertilizer use Effects on Soil Test PhosphorusOver the years, much research has centered on the use of various soil P extractants for developing soil fertility programs. While P soil test values are most reliable for estimating the historical probability of obtaining a crop response from fertilizer P application and tracking the effects of past P fertility programs - P soil tests are more commonly used as to estimate future fertilizer P rate requirements. Depending on the objectives of a grower, P soil testing is used to predict future P ra... |
147. Tillage, Fertilizer Placement Equipment and Residue Compliance- Is There a ConflictConservation compliance is no longer a nightmare for crop producers farming highly erodible land. Instead, it is rapidly becoming reality if those crop producers plan to participate in USDA agricultural assistance programs. In Missouri, farmers are adopting conservation and no-till cropping practices at a very rapid rate. Though not verified, it appears that no-till acres in many north Missouri counties more than doubled from 1991 to 1992. The most cost effective means of reducing soil erosion r... |
148. What's Ahead- Soil Conservation Service Nutrient Management PlansFarmers have been going through a major change in their relationship with Government during the past ten years. Many in the agricultural community are anticipating possibly more changes in the future from such Legislation as the Clean Water Act and the Endangered Species Act. Each act has potential of having even more impact on the agricultural community. Immediately following those two acts will be the 1995 Farm Bill. The last two Farm bills have been slanted more to environmental concerns than... |
149. Ammonia Band Spacing Effects on Ammonium Persistence in the BandResults from four field experiments (1991 and 1992) showed that anhydrous ammonia (AA) concentration in the band increased NH4-N persistence in the Hord and Sharpsburg soils in 1992, but not in the Cass and Zook soils in 1991. In 1992, average half-life across both soils was increased from 14 days when applied in a 38 cm spacing to 66 days when applied in a 152 cm spacing (every other row) at the high application rate (224 kg N ha-'). A half-life of 66 days indicates 25% of the applied AA would ... |
150. Crop Residue and Fertilizer Management Effects on Soybean, Wheat, and Grain Sorghum in Eastern KansasRemoval of crop residue is being considered for many non- agricultural uses. The agronomic consequences of these practices are not fully known, especially for different levels of fertilizer management. An experiment was begun in eastern Kansas in 1980 to determine the effects of returning different levels of crop residue on soil properties and crop yields in a soybean-wheat-grain sorghum rotation, fertilized with different amounts of N-P-K fertilizer. Crop residue treatments included residue rem... |
151. Effect of NBPT-Amended Urea and UAN on No-till Corn in Northern IllinoisField evaluations of the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) have been extensively conducted across the USA with encouraging results. Most response data collected to date has been with corn. In this report results from 7 'years of experiments at two southern Illinois locations (Belleville and Carbondale) are presented. NBPT addition to broadcast-placed urea, when evaluated across N rates and locations, gave no- till corn yield increases averaging 8.4 bulac in 13 experimen... |
152. Effects of Residue Management on Fertilizer use Efficiency on Corn in the Western Corn BeltInterest in residue management began in parts of the Great Plains following the "dirty thirties" when the government responded to wind and water erosion problems by creating the Soil Conservation Service. Stubble mulch in winter wheat production areas evolved into no-till as herbicides becan~e available. Interest in limited or no till systems in the Corn Belt began in the 1950's. Higher residue levels are required to reduce erosion while maintaining soil productivity but an additional reason is ... |
153. Field Scale Fertilizer Recommendations and Spatial VariabilityFertilizer is usually applied at a single constant rate across a field. However, soil fertility may vary considerably within a field. Soil test calibrations (ie recommended fertilizer versus soil test ) are usually obtained from sites with low spatial variability of soil test values (ex. small plots ). These calibrations are then assumed to be valid for large fields with variable soil fertility. The effects of variable soil fertility on the relationship between average crop yield response, avera... |
154. Hybrid and Potash Effects on Root Growth in Ridge-till CornPotassium deficiency symptoms often appear in ridge-till and no-till corn even when soil test values for potassium are high. Certain hybrids are morc sensitive to the problem than others. Two techniques were used to assess root activity arid density in a three year experiment at the West Central Experiment Station, Morris, MN. We compared two tillage systems (fall chisel and ridge till). two hybrids (Pioneer 3732 and 3737) and three fertilizer treatments (control and 40 IbIA banded or broadcast ... |
155. Impact of Excess Water on N LossThe impact of excess soil water on N use efficiency by corn was evaluated over several years at four locations in Illinois. At each location, 0, 4, or 6 inches of water was applied in late May to soils that were at field capacity. Prior to the addition of the excess water, potassium nitrate was applied at rates ranging from 0 to 200 Ib Nlacre. On medium to heavy textured soils, the number of days when soil moisture was at saturation provided a good estimate of the magnitude of N loss. Yields we... |
156. Influence of Water Treatment Lime Sludge on Soil pH and Crop YieldsSoil pH levels are decreasing in extreme Eastern South Dakota. To test the effectiveness of water treatment lime sludge in raising soil pH and crop yields, a liming study was established at four locations with pH levels of 5.7 or less. The lime sludge applied at 3 tons per acre raised soil pH to neutral and maintained it at neutral for the 4 year duration of the study. Crops grown at the various sites included soybeans, corn, spring wheat, winter wheat and forage sorghum. Although there was a t... |
157. Manure Brokerage in OhioIn Ohio there are several counties where annual manure production exceeds the requirements of all crops grown in the county. Poor distribution of this manure has created instances where soils have become overloaded with phosphorus, contributing to the phosphorus load of surface waters and creating the potential for long term release of phosphorus into states waters. Nitrogen also becomes an environmental concern as excess nutrient loads are placed on soils, nitrogen is found leaching through til... |
158. Michigan Right-to-Farm- Generally Accepted Agricultural and Management Practices for Nutrient UtilizationThe following is a summary of Michigan's Right-To-Farm nutrient management practices. These practices were adopted by the Michigan Agricultural Con~mission in January of 1993. Crop producers who voluntarily follow these practices are provided protection from public nuisance disputes under Michigan Public Act 93 of 1981 as amended, The Right-To-Farm Act, Michigan Department of Agriculture. A complete copy of the Right-To-Farm document may be obtained by writing to Robert Craig. Michigan Departmen... |
159. Nitrogen Management for Profitability and Groundwater ProtectionSugarbeet production practices have changed drastically in the last two decades in Minnesota and North Dakota. Changes in grower payment systems mandated change to production of high sugar content low impurity level beets. Development, refinement and extensive use of the soil nitrate-N test in concert with the sugar company quality payment program resulted in greatly reduced N fertilizer use while increasing crop yield and quality.... |
160. Nitrogen and Water ManagementIt is difficult to separate N and water management when developing improved management systems for irrigated corn production. This is because adequate supplies of both N and water are critical for crop growth, but excesses of either or both can threaten ground water quality. Several N and water management systems were established at the Nebraska Management Systems Evaluation Area (MSEA) project to evaluate the impact of improved irrigation and N fertilizer management practices on production and... |
161. Pass--An Improved System for Combining Dris and Sufficiency Range Approaches to Plant AnalysisThe University of Wisconsin Soil & Plant Analysis Lab (UW-Lab) includes both the Sufficiency Range (SR) and the Diagnosis and Recommendations Lntegrated System (DRIS) interpretations in plant analysis reports. The UW-Lab added the DRIS to its routine plant analysis program in 1992. Soon after its introduction, the DRIS appeared to be diagnosing Ca as yield-limiting in many cases where the SR interpreted Ca as sufficient. The DRIS diagnosis of Ca as deficient also contradicted previous research w... |
162. Regionalizing Fertilizer Recommendations for North Dakota, South Dakota, and Western MinnesotaFertilizer recommendations have varied between adjacent states. The inconsistencies at state lines made educational efforts in soil fertility more difficult for companies doing business across state lines. In an effort to alleviate these problems, the agronomists working with fertilizer calibration data and recommendations from the three states of North Dakota, South Dakota and Minnesota put together a recommendation system which could be used in a large part of all three states. The basic "core... |
163. Regionalizing Nutrient Recommendations Indiana- Ohio- MichiganWHY THE INTEREST IN REGIONALIZE CROP NUTRIENT RECOMMENDATIONS ? 1) Wide variations in recommendations made to farmers by who makes them. a) by fertilizer dealers or sellers of product b) by llunbiasu consultants c) by soil testing labs d) by Universities e) by other governmental agencies 2) Philosophies are different in "What is best for Mr. Farmeru a) Sufficiency Level of Fertilization - "Feed the Cropw b) Build-up & Maintenance - "Feed the Soilt1 c) Cation Balance Method - "Keep everything in ... |
164. Residue Management Systems in the Northern Corn Beltn the northern corn belt (Michigan, Wisconsin, and Minnesota) it is very important to minimize negative effects of crop residue (stand establishment and phenology). Soil cover in the row by crop residue (corn, small grain, or soybean residues) should be less than 10% in a strip 6 to 8 inches wide for corn. Mineralization of organic N sources such as legume residues, soil organic matter, and manure is reduced with systems that eliminate full width deep tillage such as ridge till, no till, or shal... |
165. Selected Soil Chemical Properties and Corn Grain Yield Under Different Manure SystemsThe Iowa Department of Agriculture and Land Stewardship estimated 1987 farm animal populations to be 4.6 million cattle and calves and 13.8 million hogs and pigs (26% of the nation's hogs). The animals produced about 141,987 tons of plant available N if 50% of the excreted N is available the first year of application. This amounts to 22 lb of N for every corn acre in Iowa. Most of the livestock operations are intensive with high populations of animals on a sniall land area. Nutrients in feed are... |
166. Survey of Corn Response to Fertilizer Sulfur in MissouriAbstract Fertilizer sulfur (S) rate studies were conducted during 1991 and 1992 at 53 sites located throughout Missouri on soils that were primarily silt loam or heavier. Sites were selected on the basis of a high yield potential since a common belief among farmers and fertilizer dealers is that the greater crop S requirement of high yields exceeds the S supply from the soil and incidental sources. Either ammonium sulfate or ammonium thosulfate were applied at planting or wihn four weeks followi... |
167. The State of the Art StartersInterest in reduced tillage has caused a resurgence in the use of starter fertilizer. Starter fertilizer research has been conducted on many crops across the country. The purpose of this paper is to highlight recent research on a variety of crops including corn. cotton, sorghum, soybean, canola, sugar beet, and potato. Increased yields from starter fertilizers are common in low P soils and several factors may lead to increased yields even when soil P and K levels are high. Geographic trends in y... |
168. Update on the Certified Crop Adviser-CCA-ProgramThe Certified Crop Adviser (CCA) program implemented by the American Society of Agronomy (ASA) and the American Registry for Certified Professionals in Agronomy, Crops; and Soils (ARCPACS) through the cooperation of various state and regional boards will soon begin its second year. To date approximately 2100 people have taken the state and/or national exams and are in the process of completing the other requirements for certification. Several new state or multi-state CCA Boards have been organiz... |
169. Use of A Wheat Cover Crop to Trap Residual Soil N for No-till CornIn continued work on long-term no-till plots, wheat was tested as a winter cover crop to determine how much carryover soil N it would accumulate from the preceding no-till corn crop and make available to the successive no-till corn crop. Wheat biomass at time of planting no-till corn was about 1.7 times greater following 240 lbs N/A on the preceding corn than following 80 lbs N/A. However, maximum wheat biomass was only about 1 T/A, and contained only 15 lbs N/A more than wheat grown following c... |
170. Variable-Rate Fertilizer Application- Update and EconomicsThe potential for application of computer-controlled, satellite-guided, variable-rate application systems for fertilizer has opened an interesting new area of research and development. While variable-rate application is not new--and does not require the com- puter or satellite systems to be useful--the technology is definitely helping to convince dealers and farmers that this concept has broader potential. Economic pressures and environmental concerns are leading them to take a closer look at ho... |
171. Calcium Chloride Effects on Nitrogen Uptake by Small GrainsApplying calcium chloride (CaC12) with urea stimulated nitrogen uptake by small grains in six greenhouse studies. The effect was most dramatic for a sandy soil, moderate for a loam soil, and not observed for a clay soil. Allowing the urea to nitrify before plant uptake negated the CaC12 effect. In field studies, these effects were generally not observed, probably because the nitrification of the applied N was too rapid. However, this concept deserves further investigation, for example, when esta... |
172. Chemical and Biological Changes Resulting from Soil SubmergenceFlooding of a soil for rice production results in significant short and long term physical, chemical and biological changes in soil properties. These changes may have significant impact of the availability of nutrients for plant growth both for aquatic plants growing in the flooded soil and upland plants on the soil when not under flooded conditions. Chief among these nutritional effects are accelerated nitrogen (N) losses, conversion of phosphorus (P) to more available forms during flooding the... |
173. Effect of Chlorophyll Meter Readings on Improving Nitrogen use Efficiency in Corn ProductionChlorophyll meters have received widespread publicity as tools to measure nitrogen status of corn. Less information is available on whether the use of chlorophyll meters will decrease total nitrogen use or increased corn grain yield. One question that remains is, "How low chlorophyll readings need to go before additional nitrogen is needed?" To determine the impact of a 2 and 4% reduction in chlorophyll readings impact on yield (as measured by a SPAD 502 meter) zero, 50, 100, 150 and 200 lbs Nta... |
174. Fertilizer Recommendations- Fact or FictionFertilizers are all important and expensive part of the crop production systenl in Indiana. Indiana farmers spend nearly a half billion dollars each year on fertilizer and lime. The question is. is this expense really nccessary? Farmers obtain fertilizer reconlmendations from a number of sources. Soil testing labs. fertilizer dealers. crop consultants and extension all make fertilizer reconunendations. In many cases the reconlmendations are quite different. Is there a valid reason for these diff... |
175. Flooded Soil Syndrom and P Deficiencies on Four Iowa SoilsSeveral million acres of Midwest cropland were inundated during the floods of 1993. The length of inundation was from a few days to several months. In some areas growing crops were drowned out and other fields could never be planted. As the water receded and acres of barren ground were exposed, the reality of the disaster gave way to concerns for the 1994 crop and the development of Flooded Soil Syndrome. Flooded Soil Syndrome produces' symptoms similar to Fallow Syndrome which was originally id... |
176. Grid Sampling- The Worth of InformationSoil sample collection and chemical analysis is a time honored, scientific procedure for providing information used in determining limestone and nutrient needs in crop production fields. Ln fact, without that information one cannot make appropriate limestone and nutrient input decisions. At best they would be educated guesses. and most likely would be incorrect. Inherently then, in the soil testing process is a worth of the information derived. This worth is dependent upon the test results and t... |
177. Grid Soil Sampling for Precision and ProfitSite specific management of plant nutrients for crop production begins with an inventory of soil test levels in a field. Fertilizer recommendations are based on the expected response to addition of fertilizers as a function of soil test levels. Therefore, the accuracy of site specific fertilizer applications depends on the precision of the soil test map from which the fertilizer recommendations are based. Precision usually increases as fields are divided and sampled as smaller areas. Mapping acc... |
178. Horse Manure ManagementIt is common in the United States to find large concentrations of horses being stabled in suburban counties, immediately adjacent to large cities. Wood sawdust is one of the most common bedding materials used for horses. The high CIN ratio present in horse manure and hardwood sawdust mixtures makes this material problematic for use in agronomic or horticultural production. The high CIN ratio can induce a nitrogen deficiency in growing crops, due to the inmobilization of soil nitrogen by micro-or... |
179. Influence of Seed Placed Fertilizer on Corn, Soybean and Sunflower EmergenceSix phosphorous fertilizer materials were placed with corn, soybean and sunflower seed to determine their influence on seed injury and emergence. Fertilizer rates used were 0, 12.5, 25, 50 and 100 Ib/A P,O, as dry TSP (0-46-O), MAP (1 1-55- 0), DAP (18-46-0) or liquid 10-34-0, 7-21-7 and 9-18-9. Seed emergence ranged from 0 to 100% depending on crop, fertilizer rate and materials used. Corn was most tolerant of fertilizer injury while soybean was extremely sensitive with stand reduction with eve... |
180. N Loss Under Excessive Water ConditionsThe impact of excessive soil moisture on N availability was reasonably well understood at the end of the 19th century when Wiley (1896) commented " Even in the case of rainfall. which may carry the soluble plant food below the arable soil, there may not be any notable loss. especially if such a downpour be followed by dry weather. But in case of heavy rains, producing a thorough saturation and leaching of the soil. the losses in a field lying fallow during the summer will be very great and it is... |
181. Nitrogen Management for No-Till Production SystemsNitrogen management practices including rates and sources were evaluated in high residue no-till production systems involving corn and grain sorghum. A urease inhibitor, N-(n-butyl) thiophosphoric triamide (NBPT) was evaluated. This research also assessed the impact of type of previous residue on performance of surface applied N. A chlorophyll meter was evaluated as an in-field N assessment tool. Results to date indicate that NBPT is effective in improving the performance of surface broadcast ur... |
182. Nitrogen Placement in No-till CornPlacement of nitrogen (N) fartilizers on no-till corn was evaluated in various single and multiple N rate experiments at the Belleville and Carbondale Research Centers of Southern Illinois University from 1983 to 1993. In 15 experiments in which granular urea placement was compared, ear leaf N and grain yield were essentially the same whether urea was broadcast or concentrated in surface bands near corn rows. Only a 2 bu/ac average yield advantage was observed for banding versus broadcasting ure... |
183. Nitrogen Recommendations for Wheat using the Chlorophyll MeterThe use of a hand held chlorophyll meter showed good promise in helping to make N recommendations for wheat on a field basis. Using 5 site-years on well drained soils over a 2- year period, a correlation index (R2) of 0.88 was found relating the March (Feekes 5) N needed for optimum yield with a differential chlorophyll reading. Research on this method will be continued and expanded to field trials. Soils in less than a well drained class may require a separate calibration or the method may not ... |
184. Remote Sensing Techniques to Identify N Deficiency in CornNitrogen management remains a primary concern for corn production. Environmental consciousness has increased the need for diagnostic techniques to identify N deficiencies to guide corrective measures or to provide feedback on management practices. This study was designed to evaluate several techniques that measure reflectance from corn plants to detect N stress. The experiment was located in Central Nebraska and involved four hybrids and five N rates. Leaf reflectance, canopy reflectance, and ae... |
185. Soil Carbon and Nitrogen Changes in a Long Term Cropping Systems StudyConserving soil C and N appears to a reasonable objective in the choice of a cropping system. Many long-term studies have been conducted where the effects of rotation or cropping system on soil C, N and other nutrients have been evaluated. A cropping systems study was initiated in 1972 on Michigan's lake bed area to 1) evaluate how often sugar beet and dry bean could be grown in a rotation and 2) determine how much crop residue needed to be returned to the soil to maintain productivity. Soil sam... |
186. Soil Fertility Research- MissouriRather than focus on one item for this years' report I thought an overview of some of the Missouri soil fertility work would be of interest. Our workgroup. though informal and scattered over campus. tries to meet weekly to provide some continuity. Much of the work is driven by grants with specific foci. For example. Newell Kitchen has reported to this group on MSEA a joint agency project to study pesticide and N movenlent into ground and surface water in a central Missouri watershed. ... |
187. Soil Fertility to Ameliorate Plant Stress from Root Feeding InsectsCorn rootworms (Diabrotica spp.) are the most serious insect pests of maize (Zea mays) in the United States. Larval stages ofthese insects feed upon maize root systems causing plant lodging and grain yield reductions. Newly developed area-wide corn rootworm adult suppression methods, which reduce pesticide rates used against this pest complex by greater than 90 percent, do not completely eliminate rootworm populations. If maize producers had the option of using crop production practices that imp... |
188. Soil Nitrate Test Performance on Medium and High-Yield Potential SoilsImproved N recommendation methods for corn (Zea mays L.) are essential for increased profitability and reduction of potential N losses to the environment. A 4-yr study (49 site-yr) was conducted to evaluate the performance of preplant (PPNT) and pre-sidedress soil nitrate tests (PSNT) for predicting optimum N rates for corn at sites with inorganic and organic N inputs. Soil samples were obtained before planting (PPNT) and when corn was 6 to 12 inches tall (PSNT). and analyzed for nitrate-N. Corn... |
189. Spacial Variability of Soil Test Phosphorus in a Northern Corn Belt FieldFor some time, an increasing number of fertilizer dealers, crop consultants, and farmers have reported substantial year-to- year variability in soil test values for phosphorus (P) and potassium (K). Frequently, this variation could be explained by such factors as extremes in soil moisture content at the time of sample collection. In many situations, however, this variation was due to the fact that soil samples were not collected from the same location in the field in two consecutive years. The i... |
190. Starter Effects on Corn Grown on Previously Flooded SoilsThe devastating floods of 1993 prompted a great deal of concern about crop production in those areas the following year. These concerns were prompted both by scientific information (Fixen et al. 1984: Vivekanandan and Fixen, 1991) and by farmer observations from prior flood experience. In response to these concerns. projects, observations. and experiments were undertaken. These included collection of soil samples for chemical analysis in the fall of 1993, observations of corn grown in 1994 on fl... |
191. Survival of Plant Growth Enhancing Root Fungi, Vesicular-Arbuscular Mycorrhizae, After Flooding and Extended FallowIn 1993. large areas of the Midwest and Great Plains were inundated with water. Plant phosphorus (P) deficiency is often a problem after such an event. Soil and plant samples were collected from sites which had been flooded and fallowed in 1993 in Missouri and Iowa. Plants from soil which low levels of starter fertilizer applied were P deficient. The application of 80 Ib P /A as starter fertilizer produced plants which were not P deficient. The flood and fallow problem was associated with the lo... |
192. The Role of Combine Yield Monitors in Nutrient ManagementA grain yield map is one of the key elements of site-specific crop management. Knowledge of spatial yield variations can serve three basic functions. First, a yield map can illuminate problems with drainage, fertility, diseases, or weed infestations that may have gone unnoticed by the producer. Secondly, a yield map is a feedback tool that will encourage a grain producer to compare different fertility treatments, planting rates, or other variations in cultural practices. Third, a yield map can d... |
193. A Systems Approach to High Yields, Efficiency and Profits in Corn, Wheat and Doublecropped Soybean RotationUsing a systems approach friendly to the environment, a three-crop/two-year no-till system has shown significiant yield increases in a three-year research project conducted at the Poplar Hill Research and Education Facility in Quantico, Maryland. In each case, corn, wheat, and doublecropped soybean yields exceeded average yields produced on Maryland's Delmarva Peninsula. Instrumental in producing these superior yields were enhanced fertility, supplemental water, and appropriate variety selection... |
194. Comparing the Performance of Preplant and Presidedress Soil Nitrate Tests for the North-Central RegionSoil nitrate (NO3-N) testing is a recommended best management practice (BMP) for adjusting corn N fertilization rates across the North-Central region. Several approaches to soil NO3-N testing are used and vary in both recommended time and depth of sampling (Hergert, 1987). Nitrate is very mobile in soil and is subject to either loss from leaching and denitrification or gain from net mineralization of crop residue and manure. The processes that govem nitrate accumulation in soils are most active ... |
195. Comparison of Mehlich-3, Olsen, and Bray-P1 Procedures for Phosphorus in Calcareous SoilsFertilizer recommendations for P generally are based on soil testing. Although a variety of soil tests are reliable for evaluating plant available P of neutral or slightly acid soils. there is still uncertainty about appropriate soil tests and soil-test interpretations for calcareous soils. The Bray-P 1 and Olsen methods are the most widely used soil-test P methods in the North Central region. Extensive research has shown that the Bray-P1 test is reliable on neutral or acid soils but that it ten... |
196. Corn Production as Affected by Daily Fertilization with Ammonium, Nitrate, and PhosphorusManipulation of N fertilization to control NH,+/NO,' ratios in the soil can affect corn (Zea mqs L.) growth and yield. Field study of these effects, however, has been difficult to conduct because nitrification of NH,+ andlor NO, leaching often occurs during the growing season. The objectives of this 4-year field experiment, were to investigate the effects of daily fertilization with various N sources and P on corn growth and yield. Pioneer 3343 was fertilized with solutions of urea (U), NH,CI, C... |
197. Effects of Residue Density, Strip Tillage, and Starter K on No-till Corn Grown in Wheat StubbleField studies were conducted in 1992 to 1994 at 2 locations in southern Illinois to evaluate the influence of wheat straw residue density and stl-ip-tillage vs no-tillage on corn growth and yield. Corn growth and resultant yield is frequently reported by producers to Se depressed in the residues of a previous wheat crop. Allelopatliy is thought to be at least partially involved. The objective of the research was to evaluate straw level (removed, remain non-modif ied, and doubled), strip tillage,... |
198. Forage Quality Management- A Key to Successful Cattle Nutrition ProgramsIn 1992, the USDA reported 59.6 million acres were harvested for hay with an average yield per acre of 2.5 ton per acre. These values gave a projected total yield of 149.1 million tons of harvested hay. Using an average market price of $72.10 per ton, total value of hay produced exceeded 10.5 billion dollars. Also in 1992, alfalfa production represented over 50 percent of the forage harvested with 79.6 million tons produced. In addition to stored forage. pasture is also a significant source of f... |
199. Improving PSNT Based Sidedress N Recommendations for Corn with Site Specific FactorsThe pre-sidedress soil nitrate test (PSNT) has been found to be a valuable tool for improving nitrogen recommendations for corn grown in humid regions of the country. The PSNT has been especially useful for nunaging N on fmls where organic sources of N, like animal manures are important. This test was proposed by Magdoff et al. in 1984 and has been studied extensively since then (Magdoff et al., 1990; Roth et al., 1992; Fox et al., 1989; Blackmer et al., 1989; Klausner et a]., 1993, and Meisinge... |
200. Influence of Potassium, Sulfur, and Zinc Fertilizer on Corn and Soybean Grown on High Tetsing SoilThe influence of potassium, sulfur and zinc fertilizer on corn and soybean yields grown on high testing soils was studied at two locations in Eastern South Dakota over a period of six years. Treatments were 50 Ibla K,O, 25 Ibla sulfur and 5 Ib/a zinc. The treatments were applied to the same plots at each location every year. Soil test levels were in the high range for all elements in question and additional nutrients would not have been recommended by the South Dakota State University Soil Testi... |
201. Nutrient Management Following CRP- Concerns and On-Going ProjectsThe future of the Conservation Reserve Program (CRP) is uncertain as this paper is being prepared, however, most agree that at some point a significant acreage currently in CRP will be brought back into production. The peak of contract expirations for the 36 million acres of CRP will occur in the fall of 1996 with the first contracts originally due to expire in 1995 (Figure 1). Many of the Northcentral states have substantial CRP acreage's making post-CRP management an important topic for this r... |
202. Nutrient Management and Starter Fertilizer for No-till CornNo-till corn acreage has steadily increased in Illinois. No-till presents unique problems of nutrient stratification, increased surface residue, and cool, wet soils which may influence nutrient availability. Two experiments were initiated in 1993 at 4 locations to evaluate the response of no-till corn to: 1) primary N applications of anhydrous ammonia preplant, UAN broadcast preplant, and ammonia sidedressed at V6; 2) starter fertilizers with factorial combinations of N, P, and K banded 2 inches... |
203. Planting Equipment for No-tillPlanters or drills have to cut and handle the residue, penetrate the soil to desired seeding depth, and establish proper seed-to-soil contact. Keeping these three items in mind, a producer can evaluate the strengths or weaknesses of any piece of planting equipment and make any adjustments or changes necessary to make no-till planting successful. Fortunately. most currently available planters and drills can be used for no-till with few, if any, modifications. In the early days of no-till, produce... |
204. Preparing for No-till Planting into CRP LandAs CRP contracts expire, many producers are considering bringing the land back into crop production. In order to conserve soil and water, and to keep the soil building benefits of idling the land for ten years, no-till is the best production system to use. Tillage will destroy the soil structure that has built up from the freeze-thaw and wetting-drying cycles. In addition, it will plant surface weed seeds and stimulate seeds which have been buried for the last ten years. Tillage will also fluff ... |
205. Real-Time Soil Nitrate SensingIon-selective field effect transistors (ISFETs) have inherent features such as small dimensions. low output impedance. high signal-to-noise ratio, low sample volumes and the potential for mass production, which are required for a real time soil sensor. However, ISFETs have the disadvantage of long-term drift, which is diminished by the use of a Flow Injection Analysis (FIA) system. In fact, FIA and ISFETs are complementary since the small sample volumes and rapid response of ISFETs allow the mi... |
206. Returning Conservation Reserve Program Land to Crop Production: Weed Management ConsiderationsThe conservation reserve program (CRP) was formulated in the 1985 Food Security Act and established to help prevent soil erosion on more than one third of the crop acres in the United States (USDA, 1986). Soil erosion represents the greatest threat in agriculture to the environment. Nationally, an estimated 750,000,000 tons of soil have been conserved as a result of CRP representing an estimated annual savings of $2 billion in off-farm clearing of eroded soil. Other benefits of CRP wildlife enha... |
207. Seed Inoculations and Nitrogen Fertilizer Trials with SoybeansCurrently there is a lot of interest in soybean seed inoculation. There are some new products on the market that are creating renewed interest in seed inoculation even on fields that have a history of soybean production. Some of the new inoculants have claims for higher potency, new and better strains of Rhizobium. higher numbers of Rlzizobiurn per gram of material, sterilized peat media, seed sticker additions and etc. Many companies are beginning to pay more attention to storage and handling o... |
208. Site-Specific Management Research in MIssouri- Swamped in Spatial DataWith a maturing GPS technology, we have over the past couple of years become very enamored with producing maps on crop production fields. It wasn't long ago that the only map available was the soil map from county soil surveys. Continued sensor development and aerial photography and sensing, along with decreasing costs to store and manipulate spatial data, will mean that in the future measuring and mapping data will be the rule. There have been a lot questions raised regarding the minimum amount... |
209. Site-Specific Management of N Fertilization in OntarioSignificant within field variability of soil properties, such as soil fertility, and plant growth have been well docome~ited. Standard soil testing practices and fertilizer recommendations which enco~npass an average soil test value for a field and a constant rate of fertilization will obviously result in certain areas of a field being either over or under fertilized. As indicated by Kachanoski and Fairchild (1995), for a single (constant) rate of fertilizer application, reconimendations based o... |
210. Site-Specific Research in North DakotaSite specific fertilizer application is currently being practiced in the Red River Valley of North Dakota/Minnesota A study has been initiated to determine sampling practices suitable for North Dakota producers using sitespecific farming both within and west of the valley. Two forty acre fields were sampled in 1994 in a 110 ft. grid, separating each sample into 0-6" and 6-24" subsamples. Smaller grid sizes were also obtained at 10 and 2 ft. grid distances in selected areas of each field. Nitrate... |
211. Starter Fertilizer Interactions with Corn HybridsThe objective of this study was to evaluate the response of corn hybrids grown in a dryland, no-tillage production system on a soil high in available phosphorus to starter fertilizer. Treatments were corn hybrids (5 in 1993 and 6 in 1994) grown with or without starter fertilizer. Starter fertilizer (30 Ib N and 30 Ib P,O,) was applied 2 inches to the side and 2 inches below the seed at planting. Nitrogen was balanced on all plots to give a total of 180 IbIA. Bray-I P level in the experimental ar... |
212. The Conservation Reserve Program- Changes on the HorizonTen years ago, Congress passed the foundation of current conservation programs--the Food Security Act of 1985. Today, one program in particular, has exceeded many peoples' expectations. The Conservation Reserve Program (CRP) yas designed to take 40 - 45 million acres of highly erodible cropland out of production for a 10 - 15 year period. As the first CRP contracts begin to expire, Congress and the Administration are grappling with the program's future in the context of the 1995 farm bill. Will ... |
213. Trapping Function of Grassed FiltersThe potential to contaminate rivers, streams, and other natural water bodies with sediment, nutrients, pesticides and bacteria in runoff from agricultural land is a very important water quality issue. Conservation tillage has proven to be effective in decreasing soil exposure to rainfall, thus decreasing water runoff and erosion potential. Vegetative filters slow down runoff that allows sediment, nutrients, pesticides and bacteria to be deposited. Combining conservation tillage with vegetative f... |
214. Using High-Tech Media Tools to Transfer the Principals of System Research to FarmersBeginning in 1981, research and extension personnel at Virginia Tech and the University of Maryland formed Intensive Wheat Management Teams. Over the next six years these Teams developed a higher yielding, more profitable and environmentally superior soft red winter wheat production system. Yields greater than 100 bu/a were achieved every year. This was at a time when average wheat yields were in the 40 bu/a range (Table 1). Intensive wheat research continues today to refine and update the syste... |
215. Changes in Iowa's Soil Test P and K Interpretations and RecommendationsResearch results from long-term and short-term experimentation in Iowa have been consistent in the response or lack of response of Iowa field crops to applications of fertilizer phosphorus (P) and potassium (K) at various soil test levels for P and K. Analyses of the research data have established critical soil test values for P and K and the most economic soil test range for P and K to maintain (Mallarino, Webb, and Blackmer, 1991a and 1991 b; Mallarino and Blackmer, 1992 and 1994; Webb, Mallar... |
216. Corn Nitrogen Tests in MissouriExperiments were carried out in farmer fields starting in 1995 with the objective of evaluating or developing field-specific tests to optimize N fertilizer rates for corn. Because some of the soil nitrate tests seem to work differently when manure or alfalfa is in the cropping system, most farms had pairs of experiments, one with an organic N source and the other with none. Descriptions of the experimental locations are given below. Location 1 2 Year 1995 1995 1995 1995 1995 PROCEDURES Countv Ca... |
217. Correlation and Calibratin of the SMP Lime Requirement Test with Direct Titration of Soil AcidityThe SMP Buffer method (Shoemaker, et al, 1961) of routinely determining lime requirement on soil samples has been used at the University of Kentucky Soil Testing Laboratory (UKSTL) since the mid-1960's. Initial correlation and calibration for Kentucky soils was a result of incubating several soil samples over a period of time after mixing different rates of lime with them (D.E. Peaslee, 1975, personal communication). During the ensuing years, county agricultural extension agents have raised many... |
218. Effect of N Fertilization on Accumulation and Release of Readily-Mineralized Organic NIncreased nitrogen (N) fertilizer use has generated concern about groundwater contamination by nitrate (NO,?. The objective of this work was to determine how previous N management and cropping system affect fertilizer N use efficiency. Research plots from a long-term N rate study on a silt loam soil were used to evaluate the impact of long term N rates on immobilization and mineralization of fertilizer N. Labeled '5~~,15~~, was applied at rates of 0, 60, 120, 180, and 240 lblacre to subplots of ... |
219. Effect of Rotation on Corn Yield and Economic Returns Under Composted Manure or Fertilizer ManagementThe benefits of growing corn in rotation with other crops as opposed to continuous corn have been mentioned in numerous research and technical publications. The benefits of adding to the crop mix include improved soil structure (Raimbault and Vyn, 1991) and soil nutrient availability (Copeland and Crookston, 1992). especially from rotations that include legumes such as soybeans or legume cover crops. Other benefits include better weed (Bhowmik and Dow, 1982). insect (Benson, 1985) and disease co... |
220. Effect of Subsoil Tillage on Crops Grown in No-Till and Reduced Till ManagementsThree different subsoil tillage experiments were conducted in southern Illinois on soils with root-limiting claypans that restrict crop growth. In the first experiment conducted at the SIU Belleville Research Center, subsoiling to 16 inches depth was compared to no subsoiling in a field that had been in long term, continuous no-till corn production. After 4 years of study, only small corn and soybean yield increases have observed with the tillage (2.0 bu/ac for corn and 1.0 bu/ac for soybeans) .... |
221. Grid Sampling or Topography Sampling for Soil NutrientsSite-specific application of fertilizers uses field soil sampling for its information basis. Many fields are currently sampled using a grid approach. In North Dakota, examination of grid sampling showed nitrate-N to follow topographic patterns in a field, allowing the possibility of less intensive sampling for N. Reviewing previous grid sampling work in Illinois, some soil properties may be associated with landscape features, including nitrate-N in the surface 6 inches and soil pH. However, Ill... |
222. Influence of Elemental Sulfur on Soil pH and Soil Test LevelsSoil test summaries from South Dakota State University Soil Testing Lab show that 16 percent of South Dakota soils have a pH of 7.6 or higher. These high pH soils can reduce nutrient availability to plants. A major concern is for reduced phosphorus availability and fertilizer use efficiency. High pH soils also reduce the availability of micronutrients such as iron and zinc. Due to these issues, questions are often asked on how to reduce soil pH. A number of materials such as sulfuric acid, alumi... |
223. Manure Management Policy IssuesTraditionally nutrient management has been concerned with optimizing the economic return from nutrients used to produce a crop. The main emphasis was on the expected crop response from adding nutrients. In practice however, manure is not always applied to optimize plant nutrient use. Historically, a common practice has been to apply commercial fertilizer without giving credit for nutrients already applied in manure. Applying manure in excess of plant needs, or at the wrong time, or handling it i... |
224. Nitrogen Availability from Composted ManureComposting of manure has been proposed to play a role in manure management programs designed to protect water quality. It is known that the biological activity involved in composting changes the nutrient availability of the material and in some cases will reduce the nutrient content. The major role of composting in alleviating some of the on-farm manure nutrient excess problems is by facilitating manure movement from a farm with an excess to a farm with a deficit of nutrients. There are several ... |
225. Nitrogen Fertigation on SoybeansNutrient requirements for soybeans are greatest as seeds are developing during reproductive pod fill. This peak nutrient demand period physiologically coincides with decreased efficiencies in both symbiotic nitrogen (N) fixation and root efficiency (Brun, 1978). Large N applications during vegetative growth stages limit N fixation and fail to consistently increase grain yields (Fla~ery, 1986). However, smaller N applications during flowering and pod fill have been reported to augment plant N sta... |
226. Nitrogen Fertilizer Equivalency of Anaerobically Digested Municipal SludgeCrop yield response to municipal sludge is largely affected by the amount of nitrogen (N) made available during the growing season. The effect of sludge rate and N fertilizer rate on either grain sorghum [Sorghum bicolor (L.)] or corn [Zea mays (L.)] yield response was studied on three fms in Lancaster county, Nebraska. A combination of five rates of dewatered (80% H20) anaerobically digested sludge and five rates of N fertilizer (NH&03) were applied before planting and incorporated by discing ... |
227. Nutrient Credits for Manure--Differences Between Theory and RealityIt has been a mainstay recommendation for many years--take credit for the nutrients in the manure you spread on your fields. While it may seem that everyone is referring to an identical procedure, there are numerous strategies to crediting nutrients contained in manure. Although it appears to be simple, the complexities involved in crediting have resulted in few livestock and crop producers properly crediting nutrients from manure. Research and educational efforts have sharply increased in the p... |
228. N x K Interactions- CornA study was conducted at OARDC-Western Branch near Springfield, OH for 4 years starting in 1992 to investigate the effects of N and K on corn production N uptake. The soil series was a Crosby Silt Loam with approximately 2.5% organic matter. All nutrients were in the above average levels on the soil test except for exchangeable K levels. See table 2 for soil test K levels. The corn hybrid Countryrnark 735 was seeded approximately the last week of April at 35,000 seeddacre. A split plot design w... |
229. Phosphorus Losses in Runoff Water as Affected by Tillage and Phosphorus FertilizationPhosphorus (P) in runoff from cropland can contribute to nutrient enrichment and eutrophication of surface water bodies. Research was continued during 1996 to determine which tillage systems and which methods of applying P fertilizer will result in the least P losses in runoff water for grain sorghum production under somewhat poorly drained soil conditions in east-central Kansas. The tillage systems evaluated were a chisel-disk-field cultivate system, a ridge-till system, and a no-till system. F... |
230. Predicting Plant Available Potassium using a Modified Sodium Tetraphenylboron MethodCurrent potassium (K) fertilizer. recommendations in the midwest are based primarily on the ammonium acetate exchangeable K (NH,OAc) soil test. In soils where nonexchangeable K comprises a major portion of plant available K, the ammonium acetate soil test is unreliable. Soil K extraction by sodium tetraphenylboron (Na-TPB) accesses both exchangeable and nonexchangeable K and mimics the action of K uptake by plant roots. A Na-TPB method utilizing a 5-minute extraction period is described, and the... |
231. Should P and K Fertilization be Matched to Plant Populations for CornFertilization practices and plant populations are major factors involved with corn production. Several researchers have investigated the effects of various fertilizer management practices. Likewise, the impact of plant population on corn production has been evaluated in a variety of production environments. The combined effects of plant popillation and fertilization. however, have not been thoroughly evaluated. Specifically. there has bcen very little study of the influence of plant populations ... |
232. Site-Specific Nitrogen ManagementApplying only the amount of nitrogen fertilizer needed for a crop at a particular point in the field makes intuitive sense - and is hard to argue against conceptually. However, in practice site-specific nitrogen (N) management is quite challenging. That is to be expected, since routine. uniform N management is often more challenging than is management of other nutrients. Because of nitrogen's mobility in soil. the fact that it is subject to a wide range of transformations and loss processes, and... |
233. Site-Specific Prediction of Soybean Nitrogen ContributionsSoybean has long been recognized for its nitrogen (N) contributions and yield enhancing effects in crop sequences. Soybean N credits in the Midwest range fiom 20 to 40 Ib of Nlacre (Kurtz et al., 1984). Several Midwestern states recommend a legume credit of 40 Ib of Nlacre following an average crop of soybean. Current Wisconsin recommendations suggest a reduction in nitrogen fertilizer rates for corn following soybean of 1 Ib N hushel of soybean yield up to a maximum credit of 40 Ib Nacre (Kelli... |
234. Spatial Analysis of Yield-Limiting FactorsThe spatial relationship between crop yields and soil and site parameters was modeled using several methods. Yield maps estimated by projection pursuit regression and neural network analysis agreed well with measured yields. These methods also allowed generation of response curves for estimated yield as a function of each of the input parameters. These response curves were useful for investigating the relationship between yields and individual soil and site parameters. ... |
235. Spatial Prediction of Crop Productivity Using Electromagnetic InductionAn inexpensive and accurate method for measuring water-related, within-field soil productivity variation would greatly enhance site-specific crop management strategies. This paper reports on investigations to use an electromagnetic induction (EM) sensor to map claypan (Udollic Ochraqualfs) and alluvial (Typic and Aquic Udipsarnnlents, and Aeric Fluvaquents) soil conductivity variations and to evaluate the relationship of EM measurements to grain crop production. Grain yield measurement was obtai... |
236. Summary of How Fertilizer Dealers Integrated Manure into Their Nutrient Management ProgramsTwo fertilizer dealers established manure brokerages in Ohio in the spring of 1992. One was in Holrnes County in Northeast Ohio with Progressive Crop Service, an independent fertilker dealer. This county is in an area which has a high concentration of poultry located in the eastern part of the county. Most of the row crop agriculture is in the western side of the county. The terrain is rolling and this is an Amish community which tends to have small fkms. The second site is in Darke County in we... |
237. Yield Monitoring- The Beginning or the EndAs site specific management or precision farming gains acceptance with the agricultural producer, the question remains: '.Where do I begin?". As technology creates and makes available new machines for the site specific environment: ''How do they fit into the picture?". As the yield monitor has become the most popular and accepted of these technological innovations for the agricultural producer, what role does it play in the sitc specific management concept? What is site specific management and w... |
238. A Field Study of Soil Test Variability, Its Effects on Accuracy of Fertilizer Recommendations, and the Subsequent Effect of Variable Rate Fertilizer Application on Soil Test ValuesThree 2.5 acre blocks were selected for intensive soil sampling from within an approximate 90 acre field which had been partitioned into 35, 2.5 acre blocks by a farm supply dealer. The 2.5 acre blocks had previously been sampled on a central composite grid basis and a variable rate fertilizer spreader (VRS) programmed for fertilizing the field. Three other more intensive sampling techniques were used to sample the 3 blocks selected for more detailed studies. Results obtained showed that soil te... |
239. Alfalfa Response to K Rate, Source and Time of ApplicationThe potassium (K) requirement of alfalfa is greater than that for any other nutrient. Potassium influences several systems within-alfalfa plants, including enzyme activity, carbohydrate production and transport, stomata1 activity: photosynthesis through chlorophyll content and CO, exchange rate, and nitrogen fixation (Munson, 1985). Potassium also markedly influences alfalfa agronomically through yield increases and improvements in forage quality, disease resistance, and overwinter survival. A s... |
240. An Evaluation of Methods for Determining Site-Specific Management ZonesNumerous procedures have been examined for identifymg management areas within fields. Traditional soil surveys give a general understanding of the effects soil mapping units have on crop productivity. In the USA. county soil surveys report the average grain yield of major crops by soil series. Slope position and landform are topographic features thal also have been used to explain water and crop productivity relationships (Mulla et al., 1992; Sudduth et al., 1997). Generally, footslope positions... |
241. Dietary P Management to Reduce Soil P Loading from Pig ManureThe potential use of phosphorus (P) based land application limits for animal manure has increased the importance of optimizing animal feed P management. The specific objectives of this study were to determine the impacts of using high available P (HAP) corn and phytase on 1) P uptake and excretion by young pigs, and 2) total P, PA-P, and water-soluble P (WSP) levels in fiesh manure generated by these pigs during a seven day digestibility trial. Our results show that, compared to the control diet... |
242. Effect of Potassium Rates and Placement on Soil Test Variability Across Tillage SystemsExperiments were conducted from 1994 through 1996 at the Dixon Springs Agricultural Center and the Belleville Research Center to evaluate K rates (60, 120, and 180 Ib KzO per acre) and placement methods in a corn and soybean rotation using chisel tillage (CT) and no-till (NT) practices. Four placement methods were used: surface broadcast, dribble, 10-inch wide surface band over each row, and banding 30 Ibs K20 per acre 2 inches to the side and 2 inches below the planted seed (remainder of the K ... |
243. Effect of Tillage, Rotation, and Nitrogen Rate on Rainfed Corn Yield and Nitrogen UptakeDetermining the long term effect of tillage, rotation and nitrogen rate in typical cropping sequences is important in making sound agronomic decisions. In northeast Nebraska rainfall is the major deternlinant of yield. In 1956 a tillage study was initiated to determine the effect of tillage. rotation and nitrogen rate on corn and soybean yields. Spring plow. disk and no-till treatments were applied to continuous corn and co1-n follo\ving soybeans on a Kennebec silt loam. Five nitrogen rates (0. ... |
244. Effect of Time and Rate of N Application on N use Efficiency and Surface Water Contamination with NitratesNitrate levels in excess of the public health standard of 10 mg N/1 in public water supplies along - with concern about hypoxia in the Gulf of Mexico have drawn renewed interest to improving fertilizer N use efficiency. Prior research has indicated that some farmers may be unkaowingly contributing to these problems. The objectives of this research were to: determine the effect of rate and time of N application on nitrate-N concentrations in water from tile lines and to evaluate the effect of pre... |
245. Foliar Fertilization of SoybeansExtensive research addressed foliar fertilization of soybeans at reproductive stages during the 70s and 80s. The soybean plant has been characterized by markedly reduced root activity during late seed development and increased translocation of nutrients and metabolites fiom other tissue into the seed. This depletion of numents from leaves could result in decreased photosynthesis. leaf senescence. and lower grain yields. Researchers theorized that if nutrients were applied directly to the foliage... |
246. Identifying Critical Sources of Phosphorus Export from Agricultural WatershedsPhosphorus (P) is an essential element for plant and animal growth, and its input to agriculture is necessary to maintain profitable crop and animal production. Eutrophication, the natural aging of lakes or streams brought on by nutrient enrichment, can be accelerated by P inputs to fresh waters from human activities (Carpenter et al., 1998; Schindler. 1977). Eutrophication has been identified as the main problem in surface waters withimpaired water quality (USEPA. 1996). It restricts water use ... |
247. Influence of Sulfur Source on CornSulfur is an essential plant nutrient. Medium and fine texture high organic matter soils in South Dakota usually supply adequate levels of sulfur to plants. Very sandy soils are less capable of supplying sulfur to plants but even these soils usually provide adequate sulfur for plant needs. However, in recent years above average precipitation may have caused leaching of sulfur, possibly resulting in sulfur deficiencies. In addition, spring soil temperatures have stayed cool, likely slowing decay ... |
248. Low-Phytate Corn- A Genetic Approach to Manure-P ManagementManaging nitrogen (N) and phosphorus (P) contained in manure produced by monogastric animals (primarily poultry and swine) is complicated because the N:P in corn grain is 6: 1 but only 3: 1 or less, in the manure. The P content in manure fiom monogastric animals becomes elevated because corn grain and many other feed sources contain most of their P as phytic acid (phytate) which is unavailable to these species because they lack the intestinal enzyme, phytase, needed to metabolize phytic acid-P. ... |
249. Nitrogen Fertilization of SoybeanNitrogen (N) requirement of soybean is high because of the high protein seed produced. One bushel of soybean requires over 3.5 pounds of N in the grain alone. Symbiotic Nz fixation supplies N for soybean, but Harper (1 974) reported that only 25 to 60% of the N in a marure soybean piant comes from N fixation while the other 40 to 75% comes from the soil. However. application of N fertilizer to soybean remains a very controversial issue because of mixed results of previous research.... |
250. Nitrogen Management in Irrigated Corn Using Remotely-Sensed Imagery and Small-Plot ExperimentsNitrogen management for irrigated corn (Zea mays L.) grown along the Arkansas River Valley in Kansas is a concern due to the hig&ly leachable soils and high water tables (ranging fiom 10-50 A). Irrigated corn usually requires a high input of N fertilizer to achieve maximum yields, and most farmers in this area have been applying a uniform rate of nitrogen across their fields every growing season based on the following KSU N recommendation. N Rec = [YG * 1.35 lbs bu-'1 STA - PCA - PYM - PNST N Re... |
251. Remotely Sensed Crop Indices for Nitrogen StressCrop nitrogen (N) stress has a strong influence on plant vigor and growth. Under field conditions, crop N stress is frequently expressed through spatial variability in biomass production and grain yield. Remote sensing serves as a useful tool to monitor crop N status by characterizing canopy reflectance because certain wavebands (i-e., colors) are sensitive to chlorophyll and crop growth. Unfortunately, interpreting reflectance data in terms of crop stress is still an inexact science. Several in... |
252. Soybean Nitrogen Aquisition and UtilizationBecause of its high seed protein concentration soybean has a huge nitrogen demand, about 350 IbdA for a 65-bu/A crop. The nitrogen is supplied by two acquisition systems that operate in tandem. In early season the plant uses soil nitrate; later its nitrogen is acquired largely through Nz fixation. On highly fertile, Midwestern soils nitrate utilization peaks at about R3 and then declines sharply. With heavy nitrogen fertilization peak nitrate utilization can be extended through R5, but ordinaril... |
253. Soybean Nitrogen Contributions and Rotation EffectsCorn-soybean rotations are widely used in Midwestern grain production. These rotations usually produce higher corn yields and require less supplemental nitrogen (N) than corn grown following corn. The yield benefits are usually attributed to rotation effects, although the precise mechanisms responsible for the yield enhancement are often not well defined. Nitrogen contributions from soybean in rotations are also not well understood because nitrogen budgets for soybean show that soybean harvested... |
254. Spring Wheat Response to Copper Fertilization in North DakotaTraditionally, copper responses have been tllought to be associated with organic soils. However, recent Canadian research has found that copper responses by wheat are possible on low organic matter, coarse textured soils. A yield response to copper in spring wheat was found in North Dakota on a coarse textured, low organic matter soil. Yield responses were not found in similar copper soil test levels of higher organic matter, heavier textured soils. A two-tiered recommendation strategy is sugges... |
255. The Potential use of Polymer-Coated Urea as a Spring Nitrogen Source for WheatMost of the soils in Northwest Ohio are medium to fine texture with poor internal drainage. Tile drainage has improved these fields, but nitrogen loss still often occurs from denitrification, especially during cold and wet springs. Growers compensate for this potential loss by applying more N at green-up or split spring applications. both of which add costs. -4 slow release N fertilizer may reduce the need for more N or split applications. One of the new time release N products is polymer-coated... |
256. The Potential use of Polymer-coated Urea as an In-Furrow Fertilizer for CornMost of the soils in Northwest Ohio are medium to fine texture with poor internal drainage. Tile drainage has improved these fields, but nitrogen loss still often occurs from denitrification, especially during cold and wet springs. The use of no-till practices has accentuated the problem. Starter fertilizers at planting have often improved the early growth of corn under these cold and wet conditions. IIowever, weather conditions may prevent timely sidedressing after planting, and cause N deficie... |
257. Tillage and Potassium Effects on Potassium use Efficiency in a Corn-Soybean RotationA field study was conducted from 1994 through 1996 at the Dixon Springs Agricultural Center @SAC) on a Bonnie sil soil and at the SlU Belleville Research Center (BRC) on a Herrick sil soil. No-till (NT) and spring chisel tillage (CT) systems were compared in a corn-soybean rotation. Within each tillage system, potassium (K) rates of 60, 120 and 180 Ib K20 per acre were combined with four placement methods that included surface broadcast, 10-inch surface band over the intended row, surface dribbl... |
258. Variability of Soil Test Phophorus and Management of Phosphorus FertilizerSoil avdable phosphorus (P) can have appreciable spatial variation wluch could result in inefficient ferthzer use. The hlgh cost of mapping ttus variab&ty may make sit2 spedc management of P uneconomic. Seed-placing a small amount of P fertrli2er has been shown to increase gain yield of corn. Therefore. it may have potential for improving P use efficiency. Ah txperiment was conducted to evaluate the spatial pattern of soil test P and the spatial response of applied P fertilizer. The scale of P v... |
259. Sidedress N applications for corn based on corn colorNitrogen-deficient corn reflects more light over the entire visible spectrum than nitrogen-suff icient corn. Our objective was to calibrate the relationship between remotely-sensed corn color and the nitrogen need of the corn. Corn color measurements were made two ways: Aerial photographs In-field spectral radiometer A successful calibration would allow: Variable-rate sidedress nitrogen applications that precisely meet the needs of the crop. Precise response to in-season N loss (Figure 1). Data ... |
260. Yield of Sugar Beet, Soybean,Corn, Field Bean and Wheat as affected by Lime Applications on High Soil pHLime from sugar beet processing plants has been stockpiled for 100 years. Environmental regulations and limited storage space provide an impetus for the removal of the material. Land application on alkaline soils is one alternative for disposal of this material. This study was undertaken to evaluate the effect of applying sugar beet processing lime on crop production on these soils. Studies were conducted at seven sites representing four alkaline soil series in Michigan. Lime was applied at rate... |
261. Assessing the Variability of Corn Response to NitrogenBecause results of experiments designed to test the response of corn to N rate tend to vary considerably with the environment. repetitions of such studies over time are essential. It is not clear, however, what number of repetitions are needed in order to deduce sound recommendations for application of N fertilizer to succeeding crops. We used the results from 16 years of a crop rotation x N rate study conducted at Monmouth, Illinois to assess the effect of duration of such an experiment on the ... |
262. Challenges for making intensive soil sampling and VRT Pay. Ongoing Iowa Studies with PhosphorusSoil fertility evaluation and management can be greatly improved with the use of precision agriculture technologies. Differential global positioning systems @GPS), yield monitors, various forms of remote sensing, geographical information system (GIs) computer software, and variable rate technologies are available for use to producers. Intensive soil sampling, crop scouting, and other practices complete the new technological package. Soil testing is a diagnostic tool especially adapted for site-s... |
263. Comprehensive Nutrient Management Plan from a USDA PerspectiveLivestock manure has emerged over the past few years as a major political, as well as an environmental issue. As the Congressional Research Service described the situation in a May 1998 report: "Social and political pressure to address the environmental impacts of livestock production has grown to the point that many policy-makers today are asking what to do, not whether to do something." It added: "The bulk of current policy debate on animal waste issues, both legislative and regulatory, is occ... |
264. Cover Crop Impacts on Corn and Soybean Nitrogen Accumulation and YieldThe need to retain soil N between economic crops has renewed interest in cover crops for the eastern cornbelt but their management remains a barrier to widespread adoption. We conducted a 3 site-yr study to determine effects of cover species (wheat or rye) and biomass management (burndown 40 d, 20 d, or 2 d preplant) on corn and soybean yields. Sites included a very poorly drained (wland wlo tile drainage) and a well drained silt loam. With adequate drainage, cover biomass 40 d preplant averaged... |
265. Early Season Stresses in CornSpatial variability in corn yield is frequently associated with lost yield potential caused by plant stresses. Early-season stresses are difficult to recognize because growing conditions (soil temperature and water status) are not ideal and seldom uniform throughout a field. The impact that climate has on plant growth is dificult to determine because it also affects nitrogen (N) availability. Nitrogen stress was imposed sequentially until the V8 growth stage and then all plots were sidedressed w... |
266. Effect of Time of N Application for CornThe economic benefit associated with the application of N fertilizers for corn has been known for over 5 decades. As a result, over 99 % of the farmers in Illinois apply N fertilizers when corn is grown. Unlike phosphorus and potassium, there is no good soil test to predict the amount of N needed, instead, farmers use a factor times yield potential with appropriate credits for legume and other N sources to set N rates. While this works well over a number of years, there are years when less N wil... |
267. Effects of Phosphorus Application Method and Rate on Furrow-irrigated Ridge-tilled Grain SorghumThe objective of this research was to investigate the effects of method of phosphorus (P) placement and rate on inigated grain sorghum grown in a ridge-tillage system on a soil low in available P. This experiment was conducted from 1993-1 995 on a producer's field near the North Central Kansas Experiment Field Experiment Field at Scandia, Kansas on a Carr sandy loam soil. Treatments consisted of fertilizer application methods: surface broadcast, single band starter (2 inches to the side and 2 in... |
268. Evaluation of Nitrogen Management Practices in No-till Corn ProductionExperiments were conducted fiom 1995 to 1998 at the Dixon Springs Agricultural Center of the University of Illinois and the Belleville Research Center of Southern Illinois University to evaluate agronomically and economically several nitrogen (N) management options, including the use of the urease inhibitor Agrotaii, in no-till corn production. Compared in these studies were N sources (urea, UAN, ammonium nitrate, and anhydrous ammonia), placement (dribble vs. broadcast for surface-applied N and... |
269. Nitrate Concentrations in Drainage Water from a Continuous Corn Production System- Impacts of Tile Spacing and Precipitation EventsCharacterization of agricultural drains as point sources for nitrates in surface waters has generated keen interest in regional grab-sample monitoring programs. Grab sample tile drain monitoring programs are being explored by numerous public and private organizations interested in encouraging BMPYs for nitrogen and/or implementation of TMDL policy. Our objective was to determine if nitrate concentrations in water collected from individual tile lines could be interpreted independent of informatio... |
270. No-till Corn Response to Starter Ffertilizer in MissouriEarly research on starter fertilizer showed that it usually increased early season crop growth, but in Missouri and adjacent states this only occasionally translated into a yield advantage. With widespread changes in tillage practices over the past twenty years, this conclusion may be changing. Recent starter fertilizer trials from other states are frequently showing corn yield responses in no-till systems. Dave Mengel at Purdue University found a yield response to starter in 8 of 11 no-till sit... |
271. Optimal Phosphorus Response in Site-specific FarmingSite-specific farming has provided an opportunity to collect large amounts of field data, but traditional agronomic yield response models have not been developed to exploit this mformation. This research presents a yield model that incorporates detailed site-specific field information (e.g., soil pH. soil test P, K, and N, fertilizer rates), providing improved fertilizer decision making. A quadratic yield response function and a modified asymptotic Mitscherlich function are compared for irrigate... |
272. Phosphate Management for the Corn Soybean RotationThe evaluation of rate, Frequency, and placement of phosphorus (P) fertilizer on production in the codsoybean rotation was evaluated for two contrasting tillage systems. A primary objective of this study was to evaluate both yield and economic response for the full crop rotation. Tillage systems compared were fall chisel plow and no-till. Application rates ranged from 0 to 92 Ibs P205 ac-' yr-l and were fall applied either annually or at double the rate on a biennial basis. The biennial applicat... |
273. Potassium Placement in Conservation Tillage- cropping System ConsiderationsSoil fertility specialists have repeatedly observed that significant stratification of both P and K occurs on fields which are kept in no-till production, even if that time period is as short as three years. The actual degree of K stratification is affected by soil texture, the method of fertilizer application, crop rotation history, precipitation levels and surface residue management. Potassium stratification isn't inherently deleterious to crop production in a given environment. Crop yield los... |
274. Relationship of Seed-placed Phosphatic Fertilizer Salt Index to Crop EmergenceThe role of fertilizer salt index in salt injury to germinating seeds has been recognized for over 60 years. Recent increased use of direct seed placement of fertilizer P has produced a need for a simpler method of making seed-placed fertilizer recommendations. Numerous field studies were conducted utilizing seed-placed P fertilizers. Published fertilizer salt index values were multiplied by the PtOs/ha application rate to give a salt indexha value. Relative plant stand (dependent variable) was ... |
275. Site Specific Nitrogen and Irrigation Management Across Nebraska Agro-ecological ZonesNitrogen leaching below hrrow irrigated ground has caused nitrate contamination in Nebraska's groundwater. Alternate row irrigation and alternate row nitrogen fertilization is proposed as a method to decrease water use and decrease nitrogen leaching. Nitrogen was applied at a uniform and variable rates based on spring grid sampling for nitrate and soil organic matter. The experiment was conducted at three sites in Nebraska that represent a range of growing conditions. At these sites the average ... |
276. Soil Fertility for Functional FoodsIn the agri-food industry today, two trends cannot be ignored. First, the health conscious "baby boom" generation is demanding and will continue to demand foods that enhance their wellness. Crop producers must increasingly focus on the goal of producing crops that meet their needs. Second, the tools of molecular biology give agricultural scientists the opportunity to attain that goal. Biotechnology involves not only genetic engineering, but also includes tools that enhance the traditional select... |
277. Soil Fertility Trends in a Long Term Crop Rotataion-Soil Fertility TrialPenn State soil test recommendations are based on fertilizing for crop response at soil test levels below the critical level for response, maintenance fertilization based on expected crop removal in the optimum range just above the critical level, and finally no fertilizer recommended in the high range. Using a sufficiency level approach, a soil that was at the critical level would have a zero recommendation, however this zero recommendation would not be valid for 3 or 4 years until a new soil t... |
278. Soil Phosphorus Chemistry- Agronomic and Environmental ApplicationsPhosphorus (P) has been a heavily researched topic in soil science for many years. For example, a search of the AGMCOLA database from 1970 to present turned up nearly 6000 citations under the key words soil and phosphorus. The fact that P is essential to all forms of life has promoted these research activities. as one would expect. In addition, the complexity of the soil P cycle has yet to be fully understood and appreciated by the scientific community. Further, while early research focused on c... |
279. Soybean Chlorosis in North Dakota- Causes, Severity and Possible SolutionsSoybean acres continue to increase in northwestern Minnesota and North Dakota in spite of severe problems with iron chlorosis in some years. Soybeans often turn yellow within a few weeks of emergence and remain yellow for up to 8 weeks before plants green up and mature. Iron chlorosis tolerant soybeans available today are somewhat effective in reducing chlorotic acreage, but are not tolerant enough to counteract the soil conditions in this area. Several researchers have found that iron chlorosis... |
280. Subsoiling No-tillage CornCurrently, over half of the corn in Kentucky is no-till planted. Many fields have received little tillage in the last 10 to 20 years. Many producers wonder if soil compaction increases with time on these long term no-till fields due to annual trafficking with heavy equipment. Subsoiling implements are available that allow subsurface tillage while preserving the surface mulch layer. This allows for continued no-till planting while introducing some tillage into the cropping system. Some producers ... |
281. Changes in Extractable P and Mineral N from Soil Recieving Fertilizer or Manure from Swine Fed Tradional or Highly Available Phosphorus Corn DietsWe compared extractable P and mineral N from soils receiving inorganic fertilizer or manure from swine fed either traditional (TC) or Highly Available Phosphorus (HAP) corn diets. The study was conducted at two sites, one with conventionally tilled irrigated corn and the other with no-tillage dryland sorghum. Manure application to a no-tillage site resulted in volatilization losses of N and greater variation in nutrient availability when cornpared to incorporated manure. When expressed as a per... |
282. Corn and Soybean Yield Response to P and K at Different Landscape PositionsSoil sampling for fertilizer recommendations is most often from the surface 15 to 20 cm (6 to 8 inches). The nutrient pool available to crops however might be quite variable when considering the spatial variation in the sub-soil nutrient pool. The objective of this research was to assess the potential interaction between claypan soil topsoil thickness (i.e., depth to the claypan) and soil-test phosphorus (P) and potassium (K) on corn and soybean crop response. Plots were established in 1996 on a... |
283. Do We Really Need a Soil Test for SulfurThe importance of sulhr (S) in a fertilizer program for crop production has been recognized for over 50 years. The need for fertilizer S was not universal. Measured responses were limited to special or localized situations. Since S in a fertilizer program was not needed for all crops and all soils, it was only logical to attempt to develop a soil test that would accurately predict the need for the addition of this essential nutrient. Development of a soil test for S that would accurately predic... |
284. Effect of Alum Water Treatment Residuals on Soils with Very High Bray P1 Soil Test LevelsAs point discharges of phosphorus (P) and other pollutants to surface waters from industrial and municipal wastewater systems have been reduced, nonpoint sources of P are now contributing a greater portion of P inputs into freshwater resources. Agricultural runoff and/or erosion can be a main contributor to this nonpoint source pollution. Continued inputs of fertilizer and manure P in excess of crop requirements have led to a build-up of soil P levels which are of environmental, rather than agro... |
285. Effect of Tillage on Legume N Credit to Winter WheatAlthough there has been a significant amount of work done on the availability of legume-nitrogen for corn following alfalfa, several questions have arisen as to the sufficiency and availability of the legume N when winter wheat is raised as a following crop. This is especially true if the wheat is planted soon after the alfalfa is killed. The synchrony of nitrogen released from legumes with crop demand for N has been a concern even with crops such as corn, where N uptake can occur through- out t... |
286. Effects of Soil Test, Tillage, and Manure and Fertilizer Application Method on Phosphorus RunoffLoss of phosphorus from agricultural lands into surface waters is of growing environmental concein. Phosphorus transported by surface runoff often ends up in streams and lakes and accelerates eutrophication, which affects the ability to use the water for drinking, fishing. recreation. etc (Foy and Withers, 1995). The niajor mechanisms by which agriculture contributes phosphorus to surface water is through runoff and erosion (Sharpley et al., 1994). Controlling run~ff and erosion from agricultura... |
287. Fall Applied Controlled-Release Nitrogen as a Nitrogen Source for Soft Red Winter WheatSoil conditions are often not conducive for timely spring N applications on wheat. Fall applications may save labor and be more economical when blended with other nutrients such as phosphorus. However, many N sources may be susceptible to loss before uptake by the wheat plant. This study evaluated fall applied controlled-release N as a N source for wheat. ... |
288. Fertilizer Recommendations Based upon Nutrient Removal or Soil Testing- A Spatial AnalysisCosts for nutrient management are generally high in crop production systems. Those costs are associated with activities related to: a) gathering information regarding soil fertility and plant nutrition for a field, b) acquisition of the actual soil amendments intended to improve the field's fertility and future crop nutrition, and c) application of the purchased soil amendments at the right rate in the appropriate place within the field. Information gathering usually consists of plant tissue and... |
289. Field Scale Evaluation of Innovative N Management Systems for CornPrevious research has shown that N fertilizer need for corn can vary widely, both between fields and within fields. Producers, however, almost always apply the same N fertilizer rate to whole fields, and vary N fertilizer rates minimally if at all over whole farms. Matching N fertilizer rates more closely to N needs could produce both economic and environmental benefits. Our objective is to test a range of innovative N management systems for their ability to match N rate recommendations to N nee... |
290. Greenhouse Gases and Carbon Sequestration Where They Fit With the Fertilizer IndustryFew things elicit more debate than the weather, and whether it is changing. Farmers in Nebraska are klly convinced that global warming is real. while farmers in Michigan arid Ontario aren't nearly as sure after this growing season. I am not going to debate whether climate change is real, or whether it is good or bad, but rather provide some background on the whole issue and how farmers and the fertilizer industry may be affected. Current scientific consensus is that greenhouse gas levels in the ... |
291. Insuring Nitrogen Best Management PracticesWhether real or perceived, the risk of losing profit by implementing best management practices (BMPs) is a major barrier in a farmer's decision process to adopt these environmentally and economically positive practices. Farmers have come to rely on agri-chemicals and fertilizers to reduce risk. Even when scientific evidence proves they are unneeded, many are slow to reduce their reliance on these inputs. Farmers need assurance that the occasional failure of best management practices will not cau... |
292. Manure Treatment and Handling OptionsManure treatment and handling will need to be an integral part of the nutrient management systems on livestock farms. No one manure system will meet the varied needs of farms with their specific nutrient management situations. The method of manure handling that will best suit each farm will vary depending on labor, land and capital resources and the manure itself. Several criteria that each farm manager will need to evaluate the treatment system that will best meet their needs are presented. A v... |
293. Nitrogen Availability, Time of Release and Movement in RotationsPrevious studies have found that N is released through the decomposition of sugarbeet tops (Moraghan and Smith, 1996: Reitmeier et a]., 1999). There is also evidence that N credits may be justified following other broadleaf crops, such as potato and sunflower. This evidence follows work by Vanotti and Bundy (1995) and Bundy et al. (1 993) suggesting that N credits from annual legumes are provided not by decomposition ofthe roots or release ofN directly into the soil from the roots as some might ... |
294. Nitrogen Management and its Influence on N Losses to Surface Water Through Subsurface Tile LinesSubsurface tile drainage from row-crop, agricultural production systems on high organic matter soils has been identified as a major source of nitrale entering surface waters in the Mississippi River Basin. Tile drainage studies have been conducted on three drainage research facilities at two locations in Minnesota since 1973. Nutrient and crop management systems including rate and time of N application. N sources (fertilizer, dairy manure and hog manure), nitrification inhibitors, cropping syste... |
295. Nitrogen Recommendations and Optimum Nitrogen Rates- How Do They CompareThe goals of University N recommendations for corn are to suggest adequate amounts of N to maximize economic return to the grower and simultaneously avoid excess N additions that can contribute to water quality problems. With increasing concerns about the contributions of aoricultural N to groundwater nitrate and to hypoxia in the Gulf of 3 Mexico. the appropnateness of N recomn~endations and their research basis are increasingly questioned. In addition, University N recommendations are often be... |
296. On-The-Go Sensors for variable rate Nutrient Management- Determining Soil K Status with a Flat-Surface Ion-Selective ElectrodeTraditional soil sampling approaches are frequently not sufficiently spatially dense to characterize within field variability in soil fertiiity. Recent technology advances have demonstrated the feasibility of using automated soil sampling systems and tractor mounted sensors to create nutrient availability maps from more continuous measurements. Our objective was to determine if a flat-surface ion selective K electrode could measure soil K status at field moisture content. Twenty-four agricultura... |
297. Phosphorus and Potassium Effects on Yield Components, Nutrient Accumulation and Persistence of Alfalfa (Medicago Sativa L.)Our objective was to determine why phosphorus (P) and potassiun~ (K) are essential for high yield by analyzing alfalfa yield components. Plots of P treatments (0, 25. 50, and 75 kg/ha) and K treatnients (0. 100, 200, 300, and 400 kgha) arranged in a factorial design were replicated four times. Forage was harvested four times per growi~lg season (1998-2000), and yield. mass per shoot, shoots per area. and herbage nutrient concentrations determined. In May and December, plants were dug to determin... |
298. Potassium Deficiency in South DakotaSouth Dakota soils are typically very high in plant available potassium (K). However in the last several years there have been increasing reports of K deficiency on corn. A number of observations have been made concerning where K deficiency occurs and what factors are involved. A few research studies have been initiated to answer frequently asked questions by producers on K management for corn and soybean rotations in the state. Preliminary results indicate differential corn variety response to... |
299. Response of Corn to N Fertilization in Fall, Spring, and (or) SummerPrecision farming technologies (remote sensing of canopy reflectance and yield monitoring) were used to study the response of corn after soybean to fertilizer N applied at different times in three field-scale trials in central Iowa in 1999. Weather conditions were unusually favorable for losses of fall-applied N and crop responses to N indicated that substantial losses occurred. Yields of corn could be maintained by adding a nitrification inhibitor or additional N, but the greatest profit was at... |
300. Site-Specific Nitrogen and Irrigation Management Across Nebraska Agro-Ecological ZonesNitrogen leaching below hrrow-irrigated ground has caused nitrate contamination in Nebraska's groundwater. Alternate row hrrow irrigation and alternate row nitrogen fertilization is proposed as a method to decrease water use and decrease nitrogen leaching. Nitrogen (N) was applied at a uniform and variable rate based on spring grid sampling for nitrate. The experiment was conducted at three sites in Nebraska that represent a range of growing conditions. At these sites, the average growing degree... |
301. Soil and Site Factors Responsible for Yield Variations in Two Southern Illinois Farm FieldsYield variability within a field is largely influenced by the soil physical. chemical. and topographic features of that field. On-farm field research studies were conducted from 1997 through 1999 on two southern Illinois farm fields (one in Jefferson County and the other in Pope County) with varying soil physical, chemical, and topographic features to determine which factors most influenced crop yield variability. Each location was GPS-gridded utilizing a grid cell size of 0.45 acres. Detailed ... |
302. Soil pH and Corn-Soybean Rotation Yield Responses to Limestone Applications and TillageFarmers growing corn and soybean in northwest Iowa must carefully consider liming needs and economics. This is because of high liniestone material cost and the fact that soils in northwest Iowa have high pH subsoil, which can moderate negative effects of acid surface soils. Another factor that must be considered is the variable effect from limestone mixing depth associated with different tillage systems. An experiment designed to evaluate six rates of aglime (0 to 6,000 Iblacre of effective calc... |
303. Spatial Variability of Soil Test Phosphorus, Potassium, pH and Organic Matter ContentAs part of a larger study investigating the potential for variable fertilizer N application in corn production, 18 field sites were established on farms across Ontario intensively sampled in the 1995 and 1996 field seasons to assess the spatial variability of soil test P, K, pH and organic matter content. Soil parameters typically display a log-normal distribution (positive skew) which would generally result in the under-fertilization of a greater area of a field if the rate of fertilization wa... |
304. Strategies for Establishing Management Zones for Site Specific Nutrient ManagementRecent precision agriculture research has focused on the use of management zones as a method to define areas for variable application of crop inputs. The goal of our work was to determine the relative importance of terrain information, aerial photographs, magnetic induction maps, and yield maps to define management zones. This work was conducted on a center-pivot irrigated field located near Gibbon. NE that has been planted to continuous corn for at least five years. Remotely sensed bare-soil i... |
305. Supplemental N on Soybeans After FloweringThis one year study evaluated the yield response of soybeans to three urea-N sources applied at R3 (early pod), R5 (early bean fill), and R6 (late bean fill) growth stages. Nitrogen sources were urea, urea plus a urease inhibitor (~grotain~) and a controlled-release N (POLYON AG@ polymer-coated urea). Seventy-five Ib per acre of actual N was applied by hand to 10 x 40 foot plots. Experimental design was a completely randonlized block with four replications. Analysis was a 3 x 3 factorial and a z... |
306. The Influence of Variably Applied Potassium Fertilizer on Yield Variations in Two Southern Illinois Farm FieldsThe basis of Variable Rate Technology (VRT) is to apply nutrients where they are needed and to reduce the application of nutrients where they are not needed. However, there is considerable uncertainty as to whether the variable application of nutrients to farmers fields should be on the basis of soil test levels or yield potentials. A field study was conducted at two locations in southern Illinois from 1997 to 1999 to evaluate VRT as a management tool for corn and soybean production on fields w... |
307. The Total Maximum Daily Loads Process in KansasThe Clean Water Act of 1972 required states to establish Total Maximum Daily Loads (TMDLs) for surface water bodies that contain one or more pollutants that exceed water quality standards. A TMDL is a written, measurable assessment of a specific stream segment and its water quality problems and contributing pollutants. This assessment outlines the amount of a pollutant that needs to be reduced to meet water quality standards. allocates control responsibilities among pollution sources in a waters... |
308. Winter Annual Legume Cover Crops in a Wheat Grain Sorghum Rotation in South Central KansasWinter annual legumes in humid regions ofthe country can have a positive effect on subsequent corn (Zea mays) and grain sorghum (Sorghum bicolor) crops, mainly through N contribution of the legume and. in some cases, soil improvement. However, water use by the cover crop in drier regions has the potential to reduce yields in subsequent crops. This study was initiated in south-central Kansas to look at the agronomic implications of adding a winter annual legume cover crop to a winter wheat (Triti... |
309. A Comparison of Producer Adoption of Precision Agricultural Practices in Denmark, The United Kingdom, and Nebraska in the United StatesWhile a lot of research and commercial development has taken place in precision agriculture in recent years there is little information available about the experience and opinions of the producers who are trying to make it pay its way in the field. Information about producer experiences in precision agriculture would be useful in guiding hture research and development in both the public and private sectors. Important questions could include: - what types of precision agriculture practices are pr... |
310. Adjusting N Recommendations Based on a Previously Grown CropNitrogen recommendations in North Dakota are based on a yield goal multiplied from some empirically derived factor in a linear formula. There are a three adjustments to the N recommendations that result form these formulas (Franzen and Cihacek, 1996). They are the soil test nitrate-N to some depth, a sampling date adjustment ifthe sampling was conducted in the fall prior to September 15, and a previous crop credit. Two of these three adjustments are based on some knowledge regarding mineralizati... |
311. Corn and Soybean Response to Potassium Fertilization and PlacementI\ncreased adoption of conservation tillage, evidence of large within-field nutrient variability, and an apparent increase in the Frequency of crop potassium (K) deficiency symptoms in Iowa and other states have prompted questions about the effectiveness of current soil-test K interpretations and fertilizer recommendations. These questions relate to fertilizer placement and management of within-field nutrient variability. Broadcast placements are less costly than banded placements but they seem ... |
312. Deep Tillage in a Corn-Soybean Production SystemMany crop producers in the Midwestern United States are currently using deep tillage, accomplished with equipment designed to run at depths of 30 to 40 cm, even though the effects of this practice are not well characterized. We assessed the effects of deep tillage, no tillage, and chisel plowing in the fall, with and without secondary tillage in the spring, on penetrometer resistance, plant stand, and yield of corn and soybean grown in rotation. In the spring, averaged across two years and six ... |
313. Detecting Spatially Variable Corn Nitrogen Needs Using Green Reflectance from 35MM PhotographsRising fertilizer costs and environmental concerns are reasons producers are looking to decrease nitrogen (N) fertilizer rates. This study investigated the use of relative green reflectance fiom 35 rnrn aerial photographs to detect spatially variable corn [Zea mays L.] N needs for developing variable rate fertilizer maps. Photographs were taken at three different growth stages (V7, V11, R3) at altitudes from 3,000 to 5,500 fi for two Missouri fields representing alluvial and deep loess soil type... |
314. Do Phosphorus TMDLs Interfere with Crop Nutrient RecommendationsHistorically, phosphorus (P) fertilizer recommendations for crops have been based on the crop grown, soil P test levels, locally correlated and calibrated yield responses, efficient use of P fertilizer, and fertilizer and crop price ratios. With the implementation of TMDLs and the need for reduced P loading in surface waters, P fertilizer applications must also safeguard water quality. In order to understand the challenges that this presents and the possible changes in P fertilizer recommendatio... |
315. Effect of Changing the Rotation Sequence in a Long Term Tillage and Fertility StudyA continuous experiment was conducted fiom 1970 to 1999 to determine the long term effects of fertilizer application and tillage practices on soil acidity, organic matter and nutrient changes, and crop responses. Four tillage treatments were evaluated: continuous conventional: alternate till (two years no-till: one year conventional); continuous chisel till; and continuous no-till. Five fertilizer treatments were also evaluated (Ib ac-' N-P205-K20): check, 0-0-0; 175-0-0 broadcast; 160-0-0 broad... |
316. Enhancing Soil Nitrogen Availability in Corn-Based Cropping SystemsThe development of sustainable N management systems requires a better understanding of the contribution of on-farm resources to the active N pool size and its mineralization. This study explores the effect of substrate diversity and living corn roots on improving N supply through mineralization. A "diverse system", consisting of a corn (Zea mays L.)-corn-soybean (Glycine mar L.)-wheat (Triticum aesiiwrm L.) rotation with cover crops and fertilized with composted manure was compared with a corn m... |
317. Evaluation of Banded Fertilizer for Soybean ProductionResponse of the soybean crop to phosphate and potash fertilizer when soil test levels indicate the need for additional P andlor K is well documented. The value of the additional bushels exceeds the cost of the fertilizer. In general, phosphate and potash fertilizer, when needed, can either be broadcast and incorporated before planting or applied in a band at the time of planting. The banded application is Frequently preferred for a variety of reasons. This is especially true when the soybean cro... |
318. Evaluation of Starter Fertilizer Formulations and Placements for Conservation Tillage Production SystemsWith the interest in and importance of the use of starter fertilizers in conservation tillage production systems, research was continued to evaluate higher rates of N in starter fertilizers and different starter fertilizer placements. The use of starter fertilizer containing N, P and K significantly increased corn yields compared to a N only program, even though soil P and K levels were high. Increasing N rates in direct seed placed starter did not increase yields and significantly reduced plant... |
319. Field Estimate of Dairy Manure Nitrogen Availability to PotatoesWithin Wisconsin, there is a distinct movement toward dairy herd expansion and consolidation of small farms. With the increase in manure production, these large dairies are considering various land and manure management arrangements with non-livestock farmers, such as potato producers. The purpose of this study is to evaluate several potato production issues resulting from such partnerships including the availability of dairy manure nutrients to potatoes. Nitrogen and phosphorus availability wer... |
320. How Does Your Garden Grow? Fertilizer- Friend or FoeGeo-spatial technologies are becoming common place in commercial agriculture and hands-on exercises using these concepts and technologies klfill many state K-12 education standards. The activity topics covered crop nutrients (nitrogen, phosphorus and potassium), global positioning systems (GPS), geographic information systems (GIs), types of agricultural field equipment, soil types and crop identification. Students developed and implemented plant growth experiments to test nutrient application h... |
321. Impact of Liquid Hog Manure and Inorganic Phosphorus (P) Fertilizer Additions on Soil Test P and P Uptake by RyegrassOntario recently introduced a phosphorus (P) index to assess the relative risk of surface water contamination resulting from P application to cropland, and to suggest possible management strategies and application restrictions to reduce this risk. The index incorporates various soiVsite characteristics (soil test P level, erosionlmnoff potential etc.) as well as management practices (rate and method of P application). Within the development of the P index, questions were raised regarding the rel... |
322. In-Season Nitrogen Fertilization of SoybeanNitrogen (N) fertilization is not a traditional nutrient management practice for soybean production in Iowa. Soybean is a legume plant and is assumed to adequately obtain needed N through symbiotic fixation. However, there has been interest over the years in using N fertilization to increase yield and grain protein due to the recognition of the large N requirement associated with high yields. Depending on the soil residual inorganic N level and soil N mineralization characteristics, approximatel... |
323. Manure and Tillage Effects on Phosphorus in RunoffPhosphorus (P) loss in runoff from cropland is an environmental concern because this P often promotes weed and algae growth in lakes, rivers, and streams. Water bodies with a large supply of nutrients (well nourished) are termed eutrophic. Eutrophic conditions can result in excessive algae and plant growth and when these weeds and algae die and decompose, dissolved oxygen levels in the water is depleted resulting in odors, fish kills, and a general degradation of the aesthetic and recreational v... |
324. Nitrate Concentrations and Flux in Drainage Water- Impacts of Tile Spacing and Precipitation Events and Implications for TMDLSIn the humid region of the eastern cornbelt efforts to optimize productivity of poorly drained soils has led to increased spatial intensity of agricultural tile drains. This intensification in installation of drainage tile is often a primary management consideration when field cultivation is being minimized or eliminated entirely. The objective of this study was to quantify the effects of tile spacing on the concentration and flux of nitrate in tile effluent. Continuous corn was grown on a well-... |
325. Previous Management Impacts on Soil Phosphorus LevelsThe Homestead Acts of the early 19th century across many areas of the United States resulted in the formation of 65 ha (160 acre) farms. The areas where livestock were concentrated on these farms consisted of a small portion of the 65 ha. As farms have become larger, many of the original farm building sites have been abandoned. These abandoned farmsteads still affect management decisions today. The objectives of this study are to show the visual and statistical relationships between both existi... |
326. Response of Corn Grown in Two Crop Rotations to Different N Rates and NitrapyrinNitrogen fertilization of corn is necessary to obtain adequate yields. Loss of soil-applied N1-L'-N fertilizers due to nitrification can decrease corn yield significantly. Nitrate contamination of ground or surface water supplies should also be considered. Use of nitrapyrin may help address these issues, though in fine textured soils response to its use is difficult to predict. A 10-year study was done to determine the effects of annual application of ammonia with nitrapyrin upon the yield of co... |
327. Site-Specific Management of Iron Deficiency in CornThe addition of FeS04mH20 in the seed row increases corn (Zea mays L.) yield in areas with Fe deficiency-induced chlorosis. Our objectives were to determine the correct application rate of FeS04.H20 for irrigated corn, identi9 the spatial distribution of Fe deficiency, and alleviate deficiency symptoms with targeted FeS04.H20 applications. Eleven site-years were selected for small-plot studies in western Kansas. At these fields, soil CaC03 content in chlorotic or problematic deficient areas of t... |
328. Site-Specific Manure Application Effects on Corn Yield and N StatusManure, a renewable resource, is an excellent source of nutrients that can be substituted for synthetic types of fertilizers. The organic matter in manure can enhance the physical and chemical properties of soils, especially infertile soils, as these soils typically contain low levels of organic matter and nutrients, and have low water holding capacities. The objective of this study was to evaluate the ability of manure application for improving crop yield and N status in less productive areas ... |
329. Soil Test Phosphorus and Potassium as Affected by Site Specific Soil Fertility ManagementThe overall objective of this field scaled study was to provide an in-field evaluation of common site specific fertilizer strategies used in corn 1 soybean production. While a team of researchers are working on several specific objectives, this work specifically focuses on three of them. First, to evaluate the variability in soil tests for making site specific phosphate (P) and potassium (K) application. Second, to measure the change in this variability over time as affected by fertilizer manage... |
330. Spatial Response of Corn to Banded Zinc Sulfate Fertilizer in IowaThe solubility of zinc (Zn) decreases as pH increases. There are soil associations that contain high pH spots within fields where the surrounding soils' pHs are slightly acid. It is reasonable to expect that Zn availability, due to a difference in solubility, is different in the two areas. The objectives of this study were to find corn (Zea nlnys L.) grain yield responses to Zn fertilizers within fields and to define the soil characteristics in responsive areas. The study was conducted at twelve... |
331. Starter Fertilizer for Corn on Lakebed SoilsMany producers use starter fertilizers because cold and wet conditions may occur zfter planting. In addition, startzr fertilizers may improve the efficiency of nutrient uptake by the crop in a sidedress system. Historically, producers in Northwest Ohio consider phosphorus the most important component of a starter fertilizer, even though research has shown that nitrogen provides most of the yield benefit. However, many fields in Northwest Ohio have more than adequate levels of phosphorus for cor... |
332. The Effect of Tillage and Lime Rate on Soil Acidity and Grain Yields of a Corn-Soybean RotationModern tillage systems, such as reduced tillage and no-tillage systems, provide shallow incorporation of surface applied materials at best. Because of concern of over-liming the surface few inches of agricultural soils, producers either reduce lime rates (and apply more often) or perform some sort of soil inversion to mix the lime deeper into the soil profile. The objectives ofthis field study were to evaluate the effects of tillage, lime rate and time of limestone application on corn and soybea... |
333. The Illinois Nitrogen Soil TestNitrogen fertilizer recommendations for corn production are often estimated on the basis of a realistic yield goal, with adjustments to allow for N credits fiom other sources, such as legumes or manure. A yield-based recommendation may have merit on a long-term basis. but under- or over- fertilization is apt to occur in any given growing season since soil N availability is not taken into account. Insufficient application of N can have serious economic consequences for the farmer, whereas excessi... |
334. Vegetative Assessment of Phosphorus and Nitrogen Status in Maize Using Remote SensingAssess spatial variability of soil P and N is not only costly but also a time consuming processes. Remote sensing measurements of canopy spectral reflectance can provide a rapid and non- destructive method for assessing plant-canopy nutrient status. The main objective of this research was to detect P and N stress during the early corn growth by selecting specific wavelengths, or combinations of them, using narrow band field sensors. In 2001, two corn experiments were planted over an old manure e... |
335. Yield Goal Versus Delta Yield to Predict Nitrogen Need in CornFertilizer nitrogen (N) needs of corn can vary widely both among and within fields. Many states use a yield goal to identi@ differences in fertilizer N need combined with an N credit system to adjust for N provided by the soil from sources such as soil organic matter, residual inorganic N and crop residues. Some have questioned yield-goal derived fertilizer N recommendations because of its poor correlation with fertilizer N need, leading some states to eliminate yield goal from their N recommend... |
336. A Case for the use of Limestone in North DakotaFarmers in North Dakota have long believed that nearly all of the cultivated land in the state was alkaline in pH. A recent survey of the state revealed that between 27% and 50% of the fields tested below pH 7, depending on landscape position, with about 17% of the state with pH less than 6.5. In site-specific studies in fields with dominant pH above 7, nearly all fields contained at least one area with pH below 7. Herbicide carryover studies have shown that areas of even slightly acid pH can re... |
337. A Crop-Based Approach for In-Season N Management of CornOver-application of nitrogen (N) fertilizer on corn has resulted in elevated levels of N in ground and surface waters. A major factor contributing to decreased N use efficiency and environmental contamination for traditional corn N management schemes is routine pre-season application of large doses of N before the crop can effectively utilize this N. Our long-term research goal is to reduce these over-applications by using remote sensing to direct fertilizer only to areas needing N at times when... |
338. Corn and Soybean Response to Sulfur Applications on Iowa SoilsHistorically sulfur (S) application has not been recommended on Iowa soils for corn and soybean production. Prior research has not determined a consistent need for S fertilization in Iowa, with field research indicating no corn or soybean yield response to applied S at virtually every site studied (Thorup and Leitch, 1975; Webb, 1978; Alesii, 1982; Killom, 1984; Sexton et al., 1998; Mallarino et al., 2000). The soil supply, in combination with sources such as manure and atmospheric deposition ha... |
339. Delivering Continuing Education to Ag Professionals- The Crop Adviser InstituteContinuing education is essential for agricultural professionals, whether required by a certifjmg organization or completed voluntarily as a supplemental educational opportunity. Agricultural continuing education has traditionally been delivered on-site, but temporal, geographical, and other constraints often prevent individuals from attending these courses. The Crop Adviser Institute (CAI) has been established to provide an alternative method of delivering continuing education. Implementation o... |
340. Developing a Natural Resource Web Site as a Training Tool for Students and AgronomistsSouth Dakota State University. Brookings SD Introduction South Dakota agronomists, agricultural workers, and students often require visual aids to demonstrate a field procedure or understand the interaction among natural resources that contribute to agricultural production. Suitable commercial products are available to serve this purpose, but they may be neither readily accessible to the public, nor particular to the state. An Internet site accessible to the public is required to display aspects... |
341. Energy and Nutrient SuppliesA study by the Potash and Phosphate Institute on 2.5 million North American soil samples has determined that soil nutrients have been withdraw without adequate replacement for several years. Soil fertility levels have dropped below optimum. At the same time, energy prices have skyrocketed, increasing fertilizer production costs. The presentation explains natural gas supplyfdemand, and how it affects both the price for natural gas and the production costs for fertilizers. The impact of this price... |
342. Enhancing Alfalfa Production Through Improved Phosphorus and Potassium ManagementAddition of phosphorus (P) and potassium (K) fertilizer is vital to maintain alfalfa productivity. The objective of this study was to examine how P and K fertilizer application increases alfalfa yield. nutrient use, and plant persistence. Replicate plots of P (0, 50, 100, 150 1bs P205/acre) and K (0. 100, 200, 300, 400 Ibs K20/acre) treatments were arranged in a factorial design. Forage harvests occurred four times annually for 5 years and yield, mass per shoot, shoots per area, and herbage nut... |
343. Estimating Second- and Third Year Nitrogen Availability from Dairy manure: It is common practice to repeatedly apply dairy manure to the same fields. To accurately assess the total plant availability of rnanure nutrients, it is necessary to account for the nutrients remaining in soil fiom previous years applications. A corn (Zea mays) field experiment has continued since 1998 on a Plano silt loam. Residual manure N availability was estimated for two and three years after a single rnanure application fiom differences in whole-plant N uptake using 1) fertilizer N equiv... |
344. Fertilizer and Manure Management Comparisons for Corn-Soybean Rotataions in MinnesotaA study was designed to evaluate the impact of P sources (fertilizer and manure), nutrient application methods (broadcast and subsurface bands), P rates (crop removal and twice crop removal), and tillage systems (no-till and conventional) on corn-soybean response. Results to date show higher yields using manure as compared to fertilizer as the P source. This could be attributed to a higher rate of P being applied using the manure. No-till systems measured greater yields in 1999 and 2000, primari... |
345. Iowa Soil-Test Field Calibration Research Update- Potassium and the Mehlich-3 ICP Phosphorus TestIowa soil-test interpretations and fertilizer recommendations for phosphorus (P) and potassium (K) were last updated in 1999. The only change from previous recommendations (Voss et al., 1996; Voss and Mallarino, 1996) was to add interpretations for the Mehlich-3 (M3) P and K tests to existing interpretations for the Bray-1 P, Olsen P, and ammonium-acetate K tests (Voss et al., 1999). The interpretations for the ammonium-acetate and M3 K tests are similar because comparisons of amounts of K extra... |
346. Nitrate Leaching Characteristics for Various Nitrogen Management Strategies on Irrigated CornEfficient use of nitrogen (N) fertilizer for corn production is important for maximizing economic return to the producer and minimizing NO3 leaching to groundwater. This is especially important on irrigated, sandy soils due to the high infiltration and saturated conductivity and potential risk to the local water supplies. This study is being conducted to quantifL the NO3 leaching potential in the irrigated sands along Kansas' waterways under current and alternative N and water management strateg... |
347. Phosphorus Runoff From Incorporated and Surface-Applied Fertilizer and ManureContinued inputs of fertiher and manure in excess of crop requirements have led to a build-up of soil phosphorus (I?) levels, creating an environmental rather than agronomic concern (Sharpley et al., 1994). The objective of this study was to evaluate the effects of soil test P level, source of P amendments, tillage, and manure application method on P runoff from agricultural soils. The treatments consisted of swine manure surface applied and injected at rates of 29 and 59 Ib acre-' of P, and tri... |
348. Phosphorus Stratification- is it Relevent to P uptake by SoybeanStratification of nutrients, observed in soils under continuous no-till management, remains an issue. Two experiments were conducted during 2001 and 2002 to evaluate the effect of stratification on P nutrition of soybean (Glycine nzax (L.) Merr.). At the fist site there were five blocks with stratified and unstratified main plots and five levels of soil test P as subplots. In the second trial there were four blocks with two stratification treatments as main plots, the absence and presence of in... |
349. Relationship Between Soil P and P in Surface Runoff and Subsurface Drainage- An Overview of Ongoing ResearchNonpoint source pollution fiom agricultural fields has the potential to accelerate eutrophication of fieshwater ecosystems. In a report of water quality in the United States, the Environmental Protection Agency sited agriculture as the primary source of pollution in 60% of impaired river miles, 30% of the impaired lake acres and 15% of estuarine square miles @PA, 1998). Phosphorus, in particular, has received much attention due to its role as limiting nutrient in many fieshwater ecosystems (Cor... |
350. Remote Sensing of Corn Canopy Dynamics and Biophysical Variables Estimation in MichiganThis study was initiated to evaluate sensor-based nitrogen and water application for corn (Zea mays L.) in Michigan. The specific objectives of this study were: 1) to identi@ wavelengths that are more sensitive to N deficiency in corn, 2) to determine when to predict corn grain yield fiom spectral remote sensing data, and 3) to estimate biophysical variables ofcorn such as leafareaindex (LAI) and fractional cover (Fc) fiom spectral vegetation indices (SVI) obtained fiom radiometric measurements ... |
351. Soil Phosphorus Spatial Distribution in Pastures Receiving Poultry Litter ApplicationsEnvironmentally-based P management strategies could be improved by debeating management zones incorporating the effects of landscape position on soil morphology, hydrology, and soil P distribution. Three farm pasture sites in SW Missouri receiving long-term poultry litter applications were sampled by landscape position (summit, shoulder, upper backslope. middle backslope, lower backslope, footslope, drain) for soil P (Bray 1 P, CaCl2 P, total P) at two depths (0-5 cm, 5- 15 cm). Low landscape po... |
352. Soybean Response to Nitrogen ApplicationsSoybean yield increases due to N fertilizer have been reported recently, particularly for N applications during the reproductive stages. It is also known that nitrate inhibits nodulat ion and nodule activity and could potentially reduce yield. Our objective was to evaluate the effect of N fertilizer on soybean yield. Forty-six experiments were conducted with N fertilizer applied at times ranging fiom planting to late reproductive stages. Some experiments had significant positive or negative resp... |
353. Starter Fertilizer Application Effect on Reduced and No-tillage Grain Sorghum ProductionThis experiment was conducted at the North Central Kansas Experiment Field, located near Belleville, on a Crete silt loam soil. Soil test P was in the high@ range. Treatments consisted oftillage systems and starter fertilizer placement and composition. Tillage systems were no-tillage and minimum tillage (spring disc and harrow treatment). Methods of starter fertilizer application included placement 2 inches to the side and 2 inches below the seed at planting (2x2) and dribbled in a band on the s... |
354. Starter, Nitrogen Management and Nitrogen Calibration- Localizing Management PracticesWhen I first started consulting with some of the fertilizer dealerships in my area, they hired me to make them different from the dealership down the road. The best way to do this was to become a local expert on scientifically-based best management practices for growing corn and soybeans in my territory. This included knowing how best to manage nutrients to grow productive and profitable crops. University and soil test laboratory recommendations provided a good starting point. However, these dat... |
355. Strip till Nitrogen Placement, and Starter Fertilizer Effects on Corn Growth and YieldStrip tillage, a system where residue is removed and small ridges are formed in the fall in the position of next year's rows, has become an increasingly popular alternative to 0-till for corn in Illinois. Over three years and eight environments in Central and Northern Illinois, tillage had no effect on grain yield: conventional tillage, strip tillage, and 0-till produced 1 1.67, 11.67, 1 1.57 Mg/ha, respectively. There were also no differences in yield due to N timing, N placement, or starter fe... |
356. Sulfur Influence on Corn and Soybean Yields in Eastern South DakotaClean air legislation, the increasing use of conservation tillage, and the manufacture of phosphorus fertilizers without sulfur have all contributed to lowering soil sulfur (S) availability to crops. Soil S availability has been affected to some extent by all three issues in eastern South Dakota. Hilltop erosion has exposed subsoil in which the pH is higher and organic matter content is lower than at lower landscape positions. In some eroded shoulder positions of the landscape in no-till fields.... |
357. Sulfur Responses and the Wisoconsin Alfalfa Sulfur SurveyFor more than 30 years, agronomists, soil scientists, consultants and farmers have recognized the potential for significant responses to applied sulfur fertilizer in northern and western Wisconsin on lighter textured, low organic matter soils that had not recently received manure (Rand et al., 1969; Hoefi and Walsh, 1975; Schulte, 1976; Peters and Kelling, 1987). More recently, crop consultants and others have reported seeing sulhr responses on soils or in locations where they typically were no... |
358. The Effect of Tillage and P Fertilizer Placement on P Runoff from Sugar Beet Production SystemsThe objective of this study was to determine the differences in the amount of phosphorus (P) in runoff fiom land under sugar beet production caused by different management practices and phosphorus fertilizer placement. The study was set up as a split plot experimental design, replicated three times. The whole plot treatments were: 1 ) codsoybean rotation, with moldboard plow as primary tillage before soybean; 2) corntsoybean rotation, with chisel plow as primary tillage before corn; 3) sugar bee... |
359. Update on the Illinois N TestEstimation of plant-available N is complicated enormously by the dynamic nature of soil N, owing largely to the effects of temperature and moisture supply on N-cycle processes. Numerous biological and chemical methods have been proposed as an index of soil N availability (Brernner, 1965; Keeney, 1982; Stanford, 1982; Bundy and Meisinger, 1994), but none has been adopted widely for soil testing. Biological methods are necessarily time-consuming because of the need for incubation, and the results ... |
360. Use of Chlorophyll Flourescence Techniques to Detect Stresses in CornIncreased efficiencies in the use of water and fertilizer will require better methods of monitoring crop stress. This study was conducted to determine whether chlorophyll fluorescence was more sensitive to detecting water and nitrogen stress than chlorophyll meters in corn (Zea mays). The experiment was carried out near Shelton, NE in 2000, 200 1, and 2002. Treatments consisted of a factorial combination of 12 corn hybrids (1 1 Pioneer Hi-Bred internationali and B73 x M017), two water levels (de... |
361. Use of Fly Ash as as Alternative Liming Source for Irrigated Corn ProductionFly ash from the Gerald Gentleman Power Station in west central Nebraska can potentially serve as an alternative liming source without reducing corn grain yields. A study was conducted to assess the use of fly ash as an alternative liming source on three acid sandy soils of west central Nebraska where conventional limmg sources can be uneconomical due to transportation costs. Corn grain yield, and soil pH change over time were assessed. Lime sources failed to raise the soil pH in the upper 8 in... |
362. Variable Nitrogen Rate ManagementIt is now more or less acknowledged that lime and N are potentially more profitable than P and K variable rate management. There is a lot of variability in optimal N rates within fields so that there is a need for variable N management. The benefits related to variable N management are generally ranked as: o Less N fertilizer used per unit yield. Savings of 15 USDIac on average for small grains. up to 41 USDIac. o Greater uniformity in crop stand, yield, grain humidity, specific weight and prot... |
363. Variable Rate Nitrogen Fertilizer for Corn Grown in KentuckyIn Kentucky, nitrogen recommendations for corn have historically been based on soil type. soil drainage class, and previous crop rather than on an anticipated yield or yield potential. Because of the growing popularity of yield monitors and GPS technology, corn producers are now accurately mapping yield variations within fields. A three year study was conducted in the karst region of western Kentucky to determine if past yield history (collected with a yield monitor using GPS) could be used as a... |
364. Variable Seeding Rates in Twin Row Planting and Micro Management of NutrientsA large scale study to determine if twin row planting, utilizing particular fertility concepts and conservational practices, out produces conventional methods of planting and fertilizing. The primary goal of the study was to increase fmer profitability and promote methods of conservational tillage. ... |
365. Varying Nitrogen and Seeding Rates of Corn Across Productivity Regions in FieldsA field study was conducted fiom 1999 to 2001 to determine the effects of variable seeding rates and variable nitrogen rates on corn (Zeu muys L.) in southern Ihois. In whole field experiments, variable seeding rates ranging fiom 18,000 to 38,000 seeds ac-' in 4.000 seed increments were planted in randomized strips (in a randomized complete block design) across the field that had soils with varying productivity based upon historical yield maps. From the yield data it was determined that the opti... |
366. Visual Correlation of Aerial Imagery with Topography and Crop YieldA study is currently being conducted on several farms to evaluate the usefulness of aerial imagery of soil and of a growing crop to delineate within-field management zones for the purposes of site-specific management. Presented is information for one site in Kent county Ontario for which correlations between aerial images taken of the soil and of the growing crop with the spatial patterns of measured topography, soil texture, and corn yield were examined. Visual interpretation indicated a very g... |
367. Zinc Deficiency Response of Sorghum, Wheat, and CornZinc (Zn) deficiency in corn (Zea mays L.) is more common than in sorghum (Sorghum bicolor (L.) Moench) or wheat (Triticum sp.). The ability of wheat to withstand low soil Zn conditions is related to increased release of phytosiderophore, a natural chelate, fiom its roots. The reasons for sorghum's ability to utilize low levels of soil Zn have not been adequately explored. The objective of this research was to: 1) ascertain if Zn deficiency can be induced with sorghum, wheat, and corn grown in a... |
368. A Weighted Classified Method for Nitrogen Zone DelineationEven though zone management in precision agriculture is a relatively new science. extensive research has been conducted on the best predictors for determining optimal nitrogen management zones in site-specific farming (Bausch et al., 2002; Fleming and Buchleiter, 2002; Franzen and Nanna, 2002, Hendrickson and Han, 2000; Lund et al.. 2002: Stenger et a].. 2002). Different techniques. varying from cluster analysis (Jaynes et al.. 2003; Kitchen et al., 2002: Ralston et al.. 2002) to neural networks... |
369. An Overview of On-Farm Nitrogen Rate ResearchBecause crop advisors, farmers, and some in the fertilizer industry questioned the University's N recommendations as being too low and raised concerns that the N calibration research had been done primarily in small plots on University Experiment Station land. numerous N calibration studies for corn after soybeans were conducted on farmers' fields in southern Minnesota and northeastern Iowa from 1989 through 2002 to validate present N recommendations. On-farm replicated trials were conducted by ... |
370. Assessing Spatial and Temporal Nutrient Dynamics with a Proposed Nutrient Buffering IndexContinued adoption of precision agriculture will lead to the accumulation of spatially and temporally dense soil fertility and yield data. Current soil fertility recommendation strategies use regional estimates of soil buffering properties to adjust application rates. A site specific nutrient buffering index (BI) is presented that uses accumulated yield maps and soil test data to locally estimate soil buffering properties relative to fertilizer additions and crop removal. BI is a quantity-inten... |
371. Comparison of Nitrogen Management Zone Delineation MethodsAn alternative to dense grid soil sampling for delineating residual soil N levels or N availability is a zone sampling approach. The zone approach assumes that soil N patterns are logically linked to some inherent causal effect, either natural or man-made. A number of delineation methods have been examined. including apparent soil EC (Kitchen et al.. 1999). yield mapping (Taylor and Whitney. 2001: Diker et al.. 2002), topography (Franzen et al.. 1998), aerial imagery (Williams et al., 2002 Srip... |
372. Corn Nitrogen Response Across Environments and Crop RotationRecent research on corn has tended to show variability in N response. Brown et al. (1993) reported that economically optimal N rates among 77 sites in Illinois ranged from zero to more than 200 lb N per acre. Results from other studies show similar variability in time and space. Even with such variability, results over environments have been combined and used to develop an N fertilizer rate guideline in Illinois based on anticipated corn yield (Hoeft and Peck, 2002). This guideline suggests pro... |
373. Deep Zone Tillage in Southeast Minnesota1 Deep Zone Tillage In SE MN (Rawson) i - --4 I Continuous corn y~eld as affected by trllage system at Rochester, 1997-00 (4-yr avg) LSD (0 10) = 3 bu - 170 IW 9 3 I 163 160 No-hll Rawson Stnp-UI Chtsel + . tillage system at Rochester, 1997-2000. LSD (0 10) = NS Rawson Stnptll Onepass Corn following soybean treatments Tillage for ' Tn # Soybean Corn 1 No-till No-till 2 Chisel + 3 No-till Ripstrip 4 Chisel + 5 No-bll Fall striptill 6 Chisel + 7 No-till One-pass 8 Chisel + 9 Chisel + Ch~sel 34kMj ... |
374. Diagnosis of Nitrogen Deficiency in Maize and the influence of Hybrid and Plant DensityThe precise diagnosis of maize N status has proven to be a difficult task because of annual 1 variation in internal N-use efficiency (kg grain kg- N uptake) and temporal change in N concentration in plant tissue. Analysis of leaf N concentration (g N leaf) has not been a consistently successful N diagnostic because of temporal and hybrid differences in specific leaf weight (SLW=g leaf me2 leaf). An alternative N diagnostic; specific leaf nitrogen (g N m-2 leaf), is unrelated to leaf mass. Maximu... |
375. Effects of Chloride From Poultry Litter and Muriate of Potash on Cured Tobacco Leaf QualityPoultry litter is growing more popular as a soil amendment in western Kentucky. due to recent poultry industry expansion. There is concern among the tobacco industry that chloride levels in poultry litter may have detrimental effects on cured leaf quality. A three year study is being conducted at the University of Kentucky to compare availability of chloride fiom poultry litter and muriate of potash and its effect on cured leaf quality. A randomized complete block design structure was chosen, wi... |
376. Evaluation of the Amino Sugar-N Based Soil test in Iowa Corn ProductionAn important improvement in estimating economic N applications for corn production would be to predict the soil N supply capacity each year. The objective of this research is to evaluate the adaptability and potential calibration of the amino sugar-N based Illinois N Soil Test in corn production fields across diverse Iowa soils. Nitrogen rate trials were conducted at multiple sites over several years, many on producer fields. Soil samples were collected at 0-6 and 0-12 inch depths in the fall an... |
377. Fertilizer Management for Strip-till and No-till Corn ProductionStrip-tillage for corn production can be advantageous over no-till. particularly in areas with heavy soils and high rainfall during spring months. Under these conditions in no-till systems. planting delays andlor slow. uneven emergence are common. Strip-tillage creates a narrow tilled area for the seedbed while maintaining the inter-row residue cover, allowing for erosion protection associated with no-till. yet providing an area in the rowr where the soil will dry out and warm up earlier in the ... |
378. Field Scale Variability of Corn Yield response Functions to Fertilizer Nitrogen ApplicationVariable rate nitrogen (N) application assumes that corn response to N fertilizer varies within a field. However, this hypothesis has not been formally tested yet. Field variation of corn response to N fertilizer and economically optimum N fertilizer rates (EON) were assessed in on- farm experiments throughout central Illinois. Fields (16 to 32 ha.) were subdivided into 13 to 20 areas. Five nitrogen rates were randomized within these areas in 28 kg N increments (2 rates) and decrements (2 rates)... |
379. Illinois Nitrogen Soil Test for Sugar Beets and Corn in MichiganIn Michigan the presidedress nitrate test (PSNT) (Magdoff et al.. 1984) is used to adjust nitrogen (N) recommendations for corn and sometimes sugar beet. Many growers do not use the PSNT because the presidedress soil sampling time does not conveniently fit into their operation. Preplant nitrate tests do not provide a good estimate of plant available N because of the relatively wet weather conditions during Michigan springs. .Another drawback to the PSNT is that it tends to recommend N on soils w... |
380. Impacts of Management, Moisture, and Phosphorus Form on Phosphorus Loss PotentialPhosphorus (P) is considered one of the major nutrients contributing to degradation of water quality in the United States. Our objectives were to examine P loss potential associated with: 1) high moisture conditions. 2) application (surface and incorporated) of manure from animals fed different diets and 3) sorption dynamics of inorganic and organic P compounds. The study of high moisture conditions evaluated the effects of near surface moisture conditions (wet and saturated), time (up to 28 day... |
381. In-Furrow Starter and Broadcast Phosphorus and Potassium Fertilization for CornIncreasing awareness of potential impacts of farming on the environment has renewed interest in further study of fertilizer management strategies that reduce nutrient inputs. Fertilizer recommendations for phosphorus (P) and potassium (K) usually are based on soil-test values and nutrient removal with crop harvest. Many Midwest fmers follow these recommendations. but many others apply removal-based P and K fertilizer rates even in high-testing soils. The typical farmer applies P and K fertilizer... |
382. Interrelationship of the Nitrogen Cycle and Carbon Sequestration- Greenhouse Gas Mitigation in Row CropsAgiculture's contribution to global warming is principally through its historical release of carbon in soil and vegetation to the atmosphere and through its contemporary release of nitrous oxide and methane. The sequestration of soil carbon in soils now depleted in soil organic matter is a well-known strategy for mitigating the buildup of COz in the atmosphere. Less well- recognized are other mitigation potentials such as better management of nitrogen fertility. A full-cost accounting of the eff... |
383. Is There a Role for Gypsum in Midwest AgricultureFor the past two years, there has been an increased interest in gypsum throughout the Midwest. It's reasonable to ask if this interest is a consequence of improved crop production or the follow-up of increasted sales activity. For many years, gypsum has been used to improve crop production in some parts of the United states. In most of these situations it was used to supply sulfur (S). In some cases, gypsum has been used to supply calcium, an important nutrient for profitable peanut production T... |
384. Long-Term Measurement of Nitrate Leaching Below Corn Agreosystems and a Restored PrairieMany studies have evaluated nitrogen leachmg from tile drained agricultural soils, but less research has been performed on many well drained soils also common throughout the Midwest. This study measured nitrate leaching fiom chisel-plow (CP) and no-tillage 0 agroecosystems in order to determine the effects of common agricultural practices on the quality of water that drains past the root zone of crops. In an effort to obtain background levels of nitrate leaching from a natural ecosystem, measure... |
385. Long-Term Nitrogen Fertilization Effects on Corn Yields and Soil PropertiesA long-term experiment (1 958-2002) provides information about the sustainability of long-term nitrogen (N) fertilizer use and continuous corn production in the northern Corn Belt. The experiment includes three N rates (none, medium, and high) applied annually in a randomized complete block design with four replications. Nitrogen rates in the medium and high categories increased over time and are currently 125 and 250 lb Nlacre. Lime treatments were imposed on the long-term N rates in 1985 using... |
386. Manganese Fertilizer Antagonism of Glyphosphate EfficacyMichigan soybean producers have observed antagonism of glyphosate efficacy in tank mixtures with foliar manganese (Mn) fertilizers. The objectives of this study were to (1) evaluate four Mn fertilizer formulations for their effect on glyphosate activity. (2) evaluate the effect of Mn fertilizer application timing on glyphosate activity, (3) evaluate the efficacy of three adjuvants in overcoming the Mn fertilizer antagonism of glyphosate. (4) determine the spray solution ratio of h4n2' and glyph... |
387. Nutrient Management Implications of Relay Cropping on the EnvironmentResidual nitrogen (nitrate-N) remaining in the root zone after seed corn production is frequently greater than under commercial corn production. This nitrate is subject to leaching into the shallow ground water of the Platte River Valley in South-Central Nebraska. as noted by elevated nitrate-N concentrations under seed cornfields compared to other fields. Hard-red winter wheat was planted into seed corn residue in early October of 2001 as a cover crop to scavenge residual- N from the root zone ... |
388. Providing Flexibility in P and K RecommendationsHistorically, land grant Universities have generally provided a single rate recommendation for nutrients such as phosphorus (P) and potassium (K). Depending on the particular University in question, these nutrient rate recommendations are generally based on two widely recognized approaches to managing soil and fertilizer P and K - the nutrient sufficiency approach and the build-maintenance approach. The goal of a nutrient sufficiency based soil fertility program is to apply just enough P andior ... |
389. Relationship Between Response Indices Measured In-Season and at Harvest in Winter WheatCurrent methods for making nitrogen recommendations in winter wheat (Triticum aestivurn L.) do not adjust for in-season temporal variability of plant available non-fertilizer nitrogen (N) sources. The purpose of this study was to compare the use of different nitrogen response indices determined in-season @INDVI and RIPLANTHEIGkm) to the nitrogen response index measured at harvest (RIHARvEST). In addition, this study evaluated the use of the in-season response indices for determining topdress nit... |
390. Savi Determination in Carrots- Comparing Constant and Dynamic Soil Adjustment FactorsReliable interpretation of reflectance measurements of vegetation in incomplete canopies is confounded by the influence of soil background. Qi et al. (2000) developed a fi-actional coverage uc) model from the NDVI of target vegetation and soil. Spectral data from a two year (2001, 2002) carrot study was used to determine if the fractional coverage (fc) model could be used to estimate the observed fractional coverage of the developing carrot canopy. Reflectance measurements and matching digital ... |
391. Site-Specific Nitrogen Management for Reducing Soil Residual NitrateSite-specific N management has potential for increasing the efficiency of N fertilizer use, and thereby reducing environmental impact. Field studies were conducted in 2000 and 2001 to evaluate the potential for site-specific N management to reduce residual soil nitrate in Missouri cornfields. Field-size side-by-side fertilizer N treatment strips were applied in cooperating farmers' fields. The site-specific crop N requirement (optimal N rate) was determined for sub- blocks that contained a full... |
392. Soil Carbon Sequestration in Agriculture- Research Efforts in the Central U.S.Since the late 1800's fossil fuel use, expansion of cultivated agriculture, and forest clearing have led to an increase in atmospheric C02 from 260 pprn to current levels >370 ppm (IPPC, 1995). Most of the recent increase in COz has been attributed to combustion of fossil fuels for energy and transportation. This increase in atmospheric COz potentially impacts climate, as it is a greenhouse gas. It has been estimated that 20-40% of targeted emission reductions in the U.S. can be met by carbon se... |
393. Starter Fertilizer for Row Crop Production Under No-till Conditions in Eastern NebraskaStarter fertilizer application often results in increased corn and sorghum yield under no-till conditions, probably due to lower soil temperatures as compared to tilled soil. Five dryland and 5 irrigated corn trials. and 12 dryland grain sorghum trials were established after soybean in 2002 and 2003 on rolling land in eastern Nebraska with different soil types and topographic positions. Three placement positions were compared: in the seed furrow. over the row. and 2" to the side and 2" deep (2x2... |
394. The Analysis of Nitrogen and Plant Population InteractionsNitrogen and plant population are significant factors for corn production. Accurate nitrogen fertilizer and seeding rate recommendations are essential for optimizing profitability for the fmer and minimizing nitrogen losses. Research and development of yield response curves provide important information that can be used to understand the relationships between these inputs (nitrogen fertilizer and corn seeds) and output (grain yield). Over the varying levels of inputs. yield response functions ca... |
395. The Importance of Soil Microorganisms in Aggregate StabilityAggregate stability is a soil quality factor. Water stability of aggregates is related to microbial activity. This paper reviews microbial inputs to aggregate stability. Soil fungi have long hair-like projections, hyphae that can physically entangle soil particles and exude glues. Microbial glues are discussed with special emphasis on arbuscular mycorrhizal (AM) fungi and the glue-like compound, glomalin. produced on hyphae of this group of fungi. Influences of management practices on AM fungi a... |
396. Timing of Spring N Application to Soft Red Winter WheatHistorically, in the northern Corn Belt, the majority of the N for winter wheat is applied as a single application when fields become green and initiate spring growth (Greenup). Time between initial spring greenup and early stem elongation (Feekes GS 6) is relatively short (four to six weeks). During this time, the potential for N loss is generally low because soil and air temperatures are cold enough to minimize volatilization and nitrification. Producers attempt to apply N at greenup because f... |
397. Urea Application Timing Influence on No-till CornFertilizer N for no-till corn in South Dakota is often limited to surface applications of urea. Surface applied urea can volatilize. A study was conducted in 1998, 1999, 2000 and 2002 (four site years) on no-till corn comparing surface broadcast urea timing. Nitrogen rates (50 and 100 Ibs Nla) were applied in the fall. winter. early spring, planting. and V-6 stage. Ear leaf samples were analyzed for N concentration in 1999 and 2000 and grain yield was measured each year. Precipitation was measur... |
398. Using Historical Yield Patterns in Fields as a Management Tool to Variably Apply NitrgenIn whole field studies in southem Illinois a uniform rate of N application was compared with variably applied rates of N based upon historical crop yields for each field. The fields used were partitioned in "low". "medium", and "high" zones of productivity depending upon the normalized yield of the preceding 5 to 10 years of crops grown. Two formulas were used to variably apply nitrogen. One formula (VRN-One) calculated a N rate that favored more fertilizer in "high" productivity regions and les... |
399. Utilizing Inhibitor Technology to reduce Ammonia Volatilization Losses from Urea Sources Applied to Conservation TillageA severe limitation to urea fertilizers and the ureacomponent in livestock wastes is the high potential for volatile loss of nitrogen (N) as ammonia. Losses are especially severe when the urea-containing materials are surface applied with no or only limited subsequent incorporation. Extensive losses are also observed when urea is applied to warm soils that are moist and undergoing rapid drylng. Soil pH, the presence of an active microbial population, and soil texture are also known to impact vo... |
400. A New Approach for Predicting Soil Nitrate Using Imagery and Non Imagery Information- Model Development and ValidationSoil nitrate, a key nutrient for optirnal gowth and development of crop, can be predicted using a new approach based on imagery and non imagery information. This paper presents an algorithm to predict soil nitrate using i~nagery and 11011 imagery infoi-~nation. LANDSAT TM satellite image, topography, soil electi-ical conductivity, crop yield, and soil type have been used to develop prediction models based on atificial intelligence technique called neural network. The models have been developed a... |
401. Active Sensor Orientation Over Corn Rows and Effect on Assessment of BiomassOur long-tern mresearch goal is to develop practical N application systems that use on-the-go remote sensing as a nleans to assess crop N status and only apply N where needed at times when the crop can most efficiently utilize N. Our preliminaty testing of two active sensor systems has shoxl-11 considerable promise for rapid and accurate assessment of canopy N status and crop biomass. In this work, the effect of sensor positioning and orientation over the canopy and their effects on assessment o... |
402. An Update on Crop Canopy Sensors for In-Season N ManagementRemote sensing in agriculture has focused 011 the spectral and spatial properties of plants. Remote sensing provides the capability for rapid collection of vast quantities of spatial data that can be analyzed quickly for use in detel-mining a course of action. This creates the potential for using remote sensing to assess and manage in-season production practices. Past research has shown that a change in canopy rel-lectance inay not be unique for a given stress. Also, other agents may have effect... |
403. Applied Nutrient Management Research at Pioneer FarmAs part of the Wisconsin Agricultural Stewardship Initiative (WASI). Pioneer Fann serties as an applied systems research and education fCm with a mission to collect and disseminate high- quality environmental and economic baseline data to students, producers, and regulatory personnel. This paper outlines the current farm operations, methods and types of data collection, current results from ongoing monitoring projccts and 1.esearc11, and details how the data is being used to support science-base... |
404. Assessing the Illinois N Test as a Decision Management Tool for SugarbeetThe Illinois nitrogen soil test (INST) was developed to detect sites where corn is nonresponsive to nitrogen (N) fertilization. Nitrogen managernent is critical for sugarbeet production because sucrose content can be compromised with excessive applications of N. The objective of this study was to assess the ability of the INST and other parameters (OM, total N, and NO3'-N) to predict N responsiveness in sugarbeet. Yield and RWSA response to N was assessed at five sites each in 2002 and 2003. IN... |
405. Changes in Nitrogen use Efficiency and Soil Quality After Five Years of Managing for High Yield Corn and SoybeanAverage corn gain yields in the USA have increased linearly at a rate of 1.7 bulacre over the past 35 years with a national yield average of 130 bdacre. Corn yield contest winners and simulation models, ho ~ever, indicate there is -100 bda in exploitable corn yield gap. Six years (1999-2004) of plant development, grain yield and nutrient uptake \yere compared in intensive irrigated maize systems representing (a) recommended best management practices for a yield goal of 200 bdacre (Ml) and (b) in... |
406. Comparison of Nitrogen Recommendation Models for Corn in Two Cropping SystemsSeveral lnodels exist to generate N recommendations, and the model selected can have both economical and environmental implications. A study was initiated in 1998 to compare the response of corn to N in two ci-opping systenls (corn following corn and corn following soybeans). All plots received a starter N rate of 45 kg N ha-' (2 x 2 placement). and five rates of sidedress N (0, 22, 90, 157, and 224 kg N hi') were applied at gro~vth stage V6 either as anhydrous arnmonia or urea-ammonium rli trat... |
407. Corn Response to Anhydrous Ammonia rate, Timing, and Inhibitor use: A RevisitationField experiments were conducted from 2001 through 2003 at three southern Illinois locations to obtain more current data on the effects of anhydrous ammonia rates. application timing, and nitrapyrin (N-Serve) use on corn. Nitrogen rates of 0. 60, 120, and 180 lbs Nlac \\ere evaluated at three times of application (fall, spring pre-plant, and sidedress) with and without nitrapqrin. Corn yield results suggest that fall anhydrous ammonia application is inferior to spring application even if nitrapy... |
408. Corn, Soybean, and Alfalfa Response to Dolomitic and Calcitic LimeCenewed interest in soil pH and liming on some of south-central Minnesota's rnost productive glacial till soils has occurred recently because: (1) intensive "grid" soil sampling has identified areas of fields that are generally considered below optimum pH ( (2) the availability of site-specific application technology to treat only below-optimum pH soils in fields that contain significant variability in soil pH, and (3) near neutral pH is believed to be necessary for achieving exceptionally high ... |
409. Development of Insite VRN as an Effective Nutrient Management ToolGrowers have significantly increased their yield levels in corn and wheat in the last 10 years. As yields increase. the amount of nutrients required has also increased to supply the crop with needed plant nutrition. Fertilizer application rates in excess of plant needs can increase the likelihood that the fertilizer may end up in ground water and streams. Mosaic developed a nutrient application tool, called Ins i te VRN, which illore accurately positions the fertilizer where it is needed for max... |
410. Do Different Corn Hybrids Have Different N NeedsThere continue to be claims that N management can be tailored to better fit specific hybrids. but there has been no recent confirmation that hybrids differ consistently in their N response. We tested the response of ten hybrids to N rates over two years (2003 and 2004) in a productive. silt loam soil near Urbana, Illinois. The previous crop was corn. Main plots consisted of five N rates (0, 60. 120, 180, and 240 Ib Nlacre), and ten Burrus corn hybrids (438Bt, 330, 442, 576, 583Bt, 625. 645, 727,... |
411. Do Miracle Products Work- A $5.50 Per Acre TreatmentDO RIIRACLE PRODUCTS WORK? A $5.50 PER ACRE TREATRENT Articles containing experimental findings often appear in popular magazines or newspapers surnnlarizing scientific work. Ofien, lack of understanding andlor eniployrnent of statistical rules can result in an oversimplification and msinterpretation of data. The objective of this study was to utilize the results from a series of expcrililents at which two penliies were randomly thrown on the "treated" plots to illustrate uses and misuses of sta... |
412. Evaluation of Fertilizer Management in Strip-till and No-till Corn ProductionStrip-tillage for corn production may have advantages over no-till. particularly in areas with heavy soils andlor high rainfall during spring months. With these conditions in no-till systems. planting delays and/or slow, uneven emergence are common. Strip-tillage creates a narrow tilled area for the seedbed ivhile maintaining the intcr-row residue cover, allowing for the erosion protection associated with no-till, yet providing an area in the row where the soil will dry out and warm up earlier i... |
413. Fertilizer Placement in Fall Strip TillageFall strip-tillage potentially provides an opportunity to increase conservation-till corn yields while sirnplifylng corn planters by minimizing the need for multiple coulters and application of relatively high rates of starter-band fertilizer associated with no-till. However. little is known about the relative efficiency of P and K application using fall strip-till systems co~npared to when starter-band applied in no-till systems. The objectives of the research reported in this study were to ev... |
414. Flax Fertility Recommendation Changes in North DakotaFlax has traditionally been grown in North Dakota since early settle~nent by European immigrants. The varieties of flax have been gro~vn for their oil content more than for fiber. Previous recommendations for N and P have becn based on yield goal and soil test level. A review of j~revious research in the region and nctv research on the role of mychorrhizae on P nutrition has resulted in dropping the P recommcndation. Due to the hazard of lodging from over-application of N from unreasonably high... |
415. Foliar Applications of K on SoybeansUse of foliar K fertilization has been extensively researched starting in the 1970's with relatively variable and inconsistent soybean yield response. However recent developments which have increased the observed incidence of I glyphosate-resistant soybeans nlay make foliar I fertilization practice may improvc the flexibility of growers to respond to decreased K availability during the growing season because of changes in environmental and rnanagement conditions. This paper details the results o... |
416. Formulating N Recommendations for Corn in the Corn Belt Using Recent DataMaking N rate recommendations for corn has been one of the most econonlically important goals of publicly funded crop production and soil fertility personnel and programs over the past five decades. Changes in cropping systems, hybrids, tillage, and other management practices, along with opportunities in site-specific inputs and awareness of the need to minimize the amount of N that reaches surface and ground waters have combined to increase the interest to re-exanline N rate recommendations, an... |
417. Induced Manganese Deficiency in GM SoybeansGlyphosate resistance in soybean and corn reduced manganese uptake and physiological efficiency. Applicatior~ of glyphosate immobilized manganese applied before, concurrent with, or within 6-8 days after the glyphosatc event. Inorganic sources of manganese (Cl, CO,, SO,) tank-mixed with gly-phosate were antagonistic and reduced herbicidal efficacy: ho~vever, antagonism was significantly influenced by glypllosate fonnulation. Glyphosate root exudates and plant deconlposition products can alter th... |
418. Influence of Soil Test Phosphorus on Phosphorus Runoff Losses from South Dakota SoilsApplications of manure and fertilizer phosphorus (P) to soil in excess of optimal crop requirements leads to a buildup of soil test phosphorus (STP) and increases the risk of offsite transfer of P during heavy precipitation events. The first step to developing effective manure and fertilizer P application strategies for South Dakota is to evaluate the relationship that exists between soil and runoff P. The objectives of this study were to: 1) determine the relationship between STP and runoff P c... |
419. Measuring Water-Extractable Phosphorus in Manures to Predict Phosphorus Concentrations in RunoffWater-extractable phosphorus (WEP) in manures can influence the risk of P losses in runoff when manures are land applied. There is some uncertainty about how WEP in manures should be determined. Specifically, are WEP measurements affected by manure sample handling before analysis, and what manure extraction procedures are most appropriate for predicting potential P runoff losses after manure application? We evaluated several manure handling and extraction variables in determinations of WEP in m... |
420. Networks of Precision Farming Trials to Evaluate and Improve Nitrogen Management for CornMost research to improve nitrogen (N) management has been conducted at relatively few locations on experimental farms. The advent of precision farming technologies offers the potential for producers to collect data on their farms. The objective of this paper is to describe how organized networks of producers using precision farming technologies can evaluate and improve N management practices. Pairs of N management practices were evaluated across many fms. Treatments were applied in alternatin... B.W. Van de woestyne, A.M. Blackmer, T.M. Blackmer |
421. Nitrogen Fertilization of Corn Grown in KentuckyApproximately 225 million pounds of nitrogen are applied to corn annually in Kentucky. Because of the dramatic rise in the price of N, fanners are reevaluating their fertilizer applications. Traditionally, research at the University of Kentucky has centered on determining the appropriate N rate for soil drainage classes and split applications to improve overall N use efficiency. Recently, new technological advancements have become available that night hrther reduce N requirements for corn. Resea... |
422. Nitrogen and Phosphorus Transport in Golf Green Sand Mixes Amended with Various Organic MaterialsNitrogen and Phosphorus are two important elements in turf and envirommental managenlent. Numerous studies have shown that nitrate and phosphate leachate is minimal off of sand golf greens amended with peat moss or inorganic amendments. Many new organic products are being used in golf course management. This study examined nitrate and orthophosphate leachate of organic amended greens with sphagurn pent moss, treated steer manure, biosolid/yard waste mix and steer + peat mix. The fertilization pr... |
423. No-till Soybean Responses to Residual Fertilizer K and Site-Specific Exchangeable K on Variable Soilst Because meeting the potassiuln (K) requirements of no-till soybean is more dependent on soil properties near the soil surface than it is in conventional soybean production, management of both tillage systems and K fertilizer application in the preceding corn crop may also be critical for the subsequent no-till soybean crop. Both stratification and spatial variability in soil exchangeable K may constrain the achievement of satisfactory yields and consistent seed quality in no-till soybean. The ... |
424. Phosphorus Fertilization Improves the Quality of Stockpiled Tall FescueStockpiling tall fescue is a recommended practice for increasing profitability of beef cattle production. However, little information is available on the mineral element composition of tall fescue pastures stored for winter grazing. In fact. analysis of the few studies reported indicates that both phosphorus and nlagnesium levels may be low in stockpiled tall fescue by late winter. The objective of this study was to determine the impact of phosphorus fertilization on improving the nutrient quali... |
425. Relationship of Mehlich-3 ICP and Mehlich-3 Colorimetric Phosphorus Determinations with the Bray-P1 ExtractantThe Bray P1 extractant has traditionally been the common extractant used for soil testing in the Midwest and Great Plains. while the Olsen P tests has been the dominant phosphorus (P) extractant used in many westem states. The use of the Meldich-3 extractant for determining soil test P in private and state operated soil test laborato~ies becotne more commonplace in recent years. The ability to extract multiple elements is a 11lajor advantage of the Mehlich-3 test. While the Mehlich-3 test is oft... |
426. Residual P Effects on Soybean Yield and Nutrient Removal RatesLong-term experiments were conducted from 1997-2003 on a Nicollet-Webster clay loan soil complex at Waseca, MN to determine the availability of residual P applied for corn on the yield and removal of P by soybeans in the following year. Phosphorus was applied either with the seed at planting as a starter, 5 to 6" deep in a band in the fall, or broadcast and incol-porated by tillage. Tillage systems included no till, strip till, spring field cultivation, and chisel plow plus field cultivation. Ti... |
427. SMS Advanced by Ag Leader Technology, Inc.SMS Advanced by Ag Leader Technology provides a software solution for creating, managing, editing, reporting, charting, visualizing, and analyzing site-specific data. The sokvare provides analysis tools usually resewed for hlghly trained individuals using high-end GIs products. that entry-level users can utilize to run attribute comparisons, write complex equations using a point and click interface, perform profillloss mapping ant1 reporting, and generate multiple year averages of yield data acr... |
428. Soil-Test Potassium Field Calibrations for Soybean Iowa Interpretations and Research UpdateThere is a long history of potassium (K) fertilization research for soybean and other crops in the North-Central Region. Sustained Iowa field research efforts focused on developing soil-test K (ST10 interpretation and on studying impacts of K fertilization strategies on grain yield and STK. Because of changes in the soil-test K method used in Iowa, this information collected over time should be evaluated separately. The field crop response and STK calibration research conducted Erom the late 196... |
429. Soil Electrical Conductivity Map Quality- Impact of Interpolation Search Neighborhood ParametersSpatial predictions of soil electrical conductivity (EC) measurements may be improved by adjusting the search neighborhood criteria. The objective of this study was to investigate how varying search parameters impacted the quality of soil EC maps. The three fields cl~osen for this study were from the Inner and Outer Blue Grass physiographic regions of Kentucky. Soil EC was measured by direct contact at all locations. The prediction datasets included EC measurements along transects that were sepa... |
430. Soil Carbon and Nitrogen Distribution and Gaseous Flux Due to Landscape Position and Temperate Alley-Cropping Practices in an Agricultural WatershedSoil NzO and COz efflux can be stimulated by agricultural practices whlch may contribute to an enhanced global warming effect. However, the efflux of these two gases in response to landscape position and soil conservation management practices such as contour strips in a temperate agoforestry alley cropping system has not been extensively studied. The objective of this study was to assess the effects of alley cropping and landscape position on soil total organic C and total N distribution and N20... |
431. Tank-Mixing Micronutrients Fertilizers with Glyphosate- Potential Problem or Efficient SolutionsTANK-MIXING MICRONUTRIENT FERTILIZERS WITH GLYPHOSATE - POTENTML PROBLEM OR EFFICIENT SOLUTION Mark L. Bernards, Kurt D. Thelen, Donald Penner Michlgan State University, East Lansing, MI Summary: Many agribusinesses are currently promoting the application of micronutrient foliar fertilizers in tank-mixtures with glyphosate for increased efficiency in glyphosate-resistant soybean production. This practice is inconsistellt with data which shows decreased glyyhosate efficacy in the presence of the ... |
432. Updating General Fertilizer Nitrogen Recommendations for Corn in OntarioCorn yield response data from field trials conducted over the past 30 years which evaluated yield response to fertilizer nitrogen (FN) in Ontario were cornpiled and reanalyzed in order to update general FN recommendations for corn in Ontario. The primary objectives of the reanalysis were to 1) determine the impact of the quadratic plateau model on FN recommendations and 2) develop a set of general recommendations that are free of adjustments based on geographical regions. The new proposed recom... |
433. Using Chlorophyll Meter Readings to Determine N Application Rates for CornOne method for refining nitrogen (N) application in corn is use of in-season crop sensing. To aid producers in making decisions regarding N rate adjustments, a calibrated relationship between sensor-derived information and expected N application need should be established. Nitrogen rate trials were conducted at multiple sitcs across Iowa in 2001-2003. Nitrogen was applied at or shortly after corn planting. Minolta SI'AD chlorophyll meter (CM) readings were collected at the R1 growth stage fiom t... |
434. A Novel Use of Data Translation Allows 3D Prediction of Soil Fertility LandscapesSoil fertility managers need better estimates of the subsoil contribution to the nutrient pool. Thls need could be achieved through 3-D predictions of subsoil fertility using a novel method of soil- profile data translation in relation to a controlling genetic horizon. For this translation, the depth of a controlling pedogenic feature is used as the origin and the rest of the profile is linearly scaled to it. When applied to a group of soils, from across a local or regional landscape, with varyi... |
435. Aerial Photos Can Predict Corn Yield Loss Due to N DeficiencyFields that experience wet weather after N fertilizer is applied may lose N and consequently lose yield. Replacing N may be difficult or expensive after corn is too tall for tractor clearance. A tool to assess the degree of potential yield loss would help corn producers decide how much expense is justified in making late N applications. ... |
436. Arbuscular Mycorrhizal Dynamics Throughout Corn Growing SeasonPhosphorous is an essential plant nutrient and is the second most common fertilizer nutrient applied in crop production. The role of mycorrhizal fungi in phosphorous (P) nutrition of corn (Zea mays L.) in high fertility soils in unclear. A study was conducted to determine the effect of extractable P on myco~hizal biomass and to evaluate the temporal dynamics of mycorrhizal fungi during the growing season in two irrigated corn fields in Nebraska. The objectives were addressed by the installation ... |
437. Assessment of Nitrogen Supply From Poultry Manure Applied to CornThe production of poultry in the state of Iowa is one of the largest in the nation and growth has continued the past few years. Currently Iowa is the number one egg producing state in the USA (USDA, 2005). This increase in production also implies an increase in manure production from poultry sources. The common end use of manure is application for crop production. Concerns exist- regarding application at rates higher than needed for crop use, with potential for contamination of water bodies due... |
438. Balancing Agronomy and Environment: N Recommendations in Ontario for the 21st CenturyThe goal of a fertilizer program may be to maximize yields from each ficld, or to maximize profit, or to minimize environmental impact. Recent instances of groundwater contamination with nitrate have focused attention on the need for source water protection, and agriculture has been implicated as one of the sources of nitrate contamination. This has lead to concerns that environmental rules could reduce the profitability of crop production, by limiting fertilizer use and hence, crop yields. Addi... |
439. Determining Economic Optimum Nitrogen Rates with the Illinois Soil Nitrogen Test and Soil Organic Nitrogen FractionsDevelopment of a diagnostic test to estimate soil N supplying capability is a continuing research need. The Illinois soil nitrogen test (ISNT) has been proposed as a method for adjusting corn (Zea Mays L.) N recommendations for to account for soil organic N contributions. We evaluated the ISNT as a tool for predicting corn N response in Wisconsin by comparing ISNT values and corn N response data from-81 experiments conducted between 1984 and 2004 with a range of crop rotations, management histo... |
440. Effect of Timing of Broadcast Potassium (K) on Soybean Yield and Seed K ContentIn Indiana, the common practice is for K fertilizer to be applied in advance of the corn crop for both crops in the rotation, relegating soybean to feed on the application residual. Producers are concerned that current University guidelines and common practices for K management in corn- soybean rotations do not fully recognize the particular K needs of the soybean crop as differentiated from the corn crop. A four-location, six-year field study was conducted to investigate the effects of rate and... |
441. Evaluation of Slow Release Nitrogen Materials in Corn ProductionStudies were conducted over a two year period to evaluate two slow release urea nitrogen carriers with regular urea for the production of corn on iirigated Spinks loamy sand. Because nitrogen availability in the soil is quite transient fiom one season to the next, annual addition of nitrogen is important for maximu~n corn yields. Many corn producers prefer to apply most of the nitrogen prior to planting corn. Once incorporated into the soil, nitrogen containing materials, such as urea, are conve... |
442. Fertilizer Nitrogen Source and Management Impacts on Greenhouse Gas EmissionsAgricultural soil management accounts for nearly 6.3% of all greenhouse gas emission in the U.S. Although fertilizer nitrogen is an essential coinponent of nearly all agricultural systems, the addition of reactive N to soils and the emission of nitrous oxide (N20) via soil microbiological processes (nitrification and denitrification) makes U.S. agriculture the largest source (62%) of total U.S. N20 emissions. Because N20 is a potent greenhouse gas with a forcing potential more than 300 times gre... |
443. Hybrid Maize A Simulation Model for Improving Corn ManagementHybrid-Maize (www.hybridmaize.unl.edu) is a computer program that simulates the growth and yield of a corn crop under non-limiting or water-limited (rainfed or irrigated) conditions. The model can be used to (1) assess the overall site yield potential and its variability based on historical weather data, (2) evaluate changes in attainable yield using different combinations of planting date, hybrid maturity and plant density, (3) analyze yield in relation to silking and maturity in a specific yea... |
444. Impact of Nitrogen and Sulfur Fertilization on Wheat Yield and QualitySulfur (S) contributed by rainfall has decreased by 50% over the last twenty-seven years and may increase the need for S supplementation by fertilization. Nitrogen (N) application is typically split applied in Ohio with some applied in the fall and remainder applied in the spring near first green-up. The objective of this study was to compare N application source and timing with and without S fertilization. Two experimental locations were established in the fall of 2004. Urea and urea-ammonium n... |
445. Impact of Stratified Potassium and Water Content of No-Till Soils on Soybean Growth and YieldLow potassium (K) concentrations in subsurface soil and reduced water content in the K- enriched surface soil are thought to cause K-related yield reductions in rain-fed soybean (Glycine max L. Merr.). Our objectives were to examine root-to-shoot ratios through ontogeny and yield components in relation to stratified soil water and K. Soil and plant samples were collected at V6, R2, R4, and R6 from a 2-year field study. Additionally, a greenhouse split-root ot study in P a complete factorial des... |
446. Improving the Fermentation Characteristics of Corn Through Optimum Fertilization and Hybrid SelectionEthanol processors could increase production efficiency if they had access to corn grain better- suited for fermentation. The objective of this study was to determine the influence of hybrids and N fertility rates on fermentable starch content that will be used for dry-mill ethanol production. Six hybrids were grown under four N fertility levels at two locations in eastern SD. Ethanol yields increased as N fertility levels increased. Higher ethanol yields were achieved by hybrids that produced b... |
447. In Season RecommendationsWe are testing a prototype high-clearance tractor configured with active crop canopy sensors, drop nozzles with electronic valves, and a variable rate controller as means to deliver in-season variable rates of liquid N fertilizer based on crop needs as an alterative to preplant uniform applications of N. The active sensor we're evaluating is the model ACS-210 Crop Circle made by Holland Scientific. It generates it's own source of modulated light in the amber and near infrared (NIR) bands and the... |
448. Introgressing Unique Sources of Germplasm to Improve N Use in Temperate MaizeThe vast majority of maize breeding efforts have been conducted under high N environments that primarily select for only one component of NUE, N uptake. Furthermore, these studies have employed US. and European genotypes, which have been selected for performance at high N. Historically, maize was grown in numerous low N tropical environments, suggesting that evaluation of adapted maize lines containing tropical germplasm may harbor useful genetic variation and novel alleles for improving NUE. Th... |
449. Long Term Outlook On Nitrogen and Potassium SupplyThe North American fertilizer industry is operating in world market today. Worldwide fertilizer demand, competition for transportation, and natural gas prices are all putting pressure on North American fertilizer prices. The themc of this mornings' session is on strategies the supply industry and fanners may adopt to manage these pressures. This talk is about the near future outlook nitrogen and potassium fertilizer. Fertilizer sales figures indicate that nitrogen, phosphorus. and potassium fer... |
450. Making Urea Work in No TillNo-till and reduced tillage production systen~s are widely used today in the United States as well as around the world due to their capacity for reducing soil erosion and topsoil loss, reducing phosphorus movement to surface water, and reducing labor, fuel, and equipment requirements. In no-till systems, an average of 25% of the N applied as broadcast urea can be lost via ammonia volatilization. Therefore, N losses due to ammonia volatilization will decrease corn and wheat yields. independently ... |
451. Managing Continuous Corn for High YieldsMany "contest-winning" corn yields have historically been produced in fields where corn is grown continuously, often with extensive tillage, hgh soil test values of P and K, high N rates, and high plant populations. We are conducting a series of research trials at four sites in Illinois, in whlch we are varying tillage, fertilizer rates, and plant population in a factorial experiment at several Illinois locations. Over ten site-years to date, tillage deeper than normal increased yield at two sit... |
452. Near Seed Application of Fluid Fertilizer for Corn Soybean and Sugarbeet ProductionIn recent years, crop producers in Minnesota have shown increased interest in placing fertilizer near the seed at planting. The more traditional 2x2 "starter" band was not an option. Guidelines were needed for banded placement of fertilizer near the seed at the time of planting. This study was conducted in 2004 and 2005 in fields of cooperating crop producers. Three fluid . materials (10-34-0, 4-10-10, 3-18-18) were applied at two rates for corn, soybeans and sugarbeets. In 2004, the materials w... |
453. Opportunities and Limitations of Automatic Steering TechnologiesIn the short span of 10 years we have gone from using the Global Positioning System (GPS) to locate ourselves in a farm field, to automatically steering a machine working in the field. This application requires about 15 conlponents with each component evolving at a rapid pace. A number of conlpanies have formed to provide automatic steering packages as aftermarket retrofits. At a slightly slower pace, the main equipment manufactures are engineering machines that will be factor ready or factory e... |
454. Phosphorus and Potassium Place in Corn-Soybean Systems in the Midwest: Possibilities with Automatic Guidance TechnologyGlobal positioning system teclmology available to the public has become more accurate in recent years. Current Real Time Kinematic (RTK) techniques allow relative positions of equipment to be recorded with 3/8 - 2 in. precision (Dana, 1991). Being able to return to the same location in the field year after year with high precision may have implications for corn-soybean systems where banded applications of phosphorus (P) and/or potassium (K) are made at a time other than at planting. The importan... |
455. Regional Approach to Making Nitrogen Fertilizer Rate Decisions for CornNitrogen fertilizer is one of the largest input costs for growing corn. Across the Corn Belt, N is typically the most yield-limiting nutrient. Facing record high N fertilizer prices and potential supply problems, producers are concellled about N fertilization rates. Soil fertility researchers and extension specialists froin seven states across the Corn Belt (see list in acknowledgements section) have been discussing corn N fertilization needs and evaluating N rate recommendation systems for appr... |
456. Scale of Measurement Effects on Phosphorus Runoff Losses from CroplandAs phosphorus (P)-based nutrient management planning becomes necessary for some farms in Wisconsin, it will be critical to have reliable, research-based planning tools. The Wisconsin P- hdex provides one method for preparing P-based nutrient management plans. The P-Index was developed largely from small plot-scale data showing the relationships between various site and management variables and runoff P losses. Thls study was conducted to compare runoff composition measurements at the subwatershe... |
457. Slow Release Nitrogen Fertilizer and Dynamics in Soil Systems Part I Incubation StudyA lab study was conducted at Southern Illinois University soil fertility research facility to investigate the effects of soil type on the nitrogen (N) release dynamics. The objective of this study was to identify the effect of soil type on the release rate of N from slow release nitrogen (SRN) fertilizers under controlled conditions (moisture and temperature). Two contrasting soils from Iowa and Georgia (pH and mineralogy) were combined with 500 mg kg-, of SRN or urea and kept for 90 days under ... |
458. Strip Tillage and No Tillage Fertilization Systems Evaluated for Eastern Kansas Rain Fed CornRow-crop agriculture in East-Central and Southeast Kansas is facing increasing pressure to reduce sediment and nutrient losses via runoff. Edge-of-field measurements show that no-tillage with fertilizers placed below the surface of the soil has significantly less sediment and total P losses in runoff compared to conventional tillage (Janssen et al., 2000). However, for rain-fed corn, no-tillage in these regions can provide serious challenges some years because of frequent spring rains and an abu... |
459. Study on Phosphorus and Nitrogen Concentration of Corn Adapted in South DakotaThough nitrogen (N) and phosphorus (P) are vital in several physiological and developmental processes in plants and animals, they pose several environmental, nutritional and health problems, if present in excess amounts. Reduction in the excess input of these nutrients into the soil, thereby reducing environmental problem and consequently nutritional and health problem, can be achieved by balancing their concentration in animal feed. Therefore, this research aims to quantify the nitrogen and pho... |
460. Swine Manure Phosphorus Use for Crop Production in IowaImproving manure phosphorus (P) management guidelines should result in a more efficient use of thls resource for crop production and in lower risk of P loss to surface water resources. Phosphorus fertilizers are widely used in crop production, there is a great deal of information about their use, and farmers have little doubt about their value to improve crop yield in low- testing soils. However, there is a great deal of uncertainty concerning the value of manure nutrients for crops and about co... |
461. The Influence of Nitrogen Rate and Foliar Fetilization on Yield and Nitrosamine Levels in Burley TobaccoMany burley tobacco (Nicotiana tabactm~ L.) producers believe that additions of nitrogen (N) rates greater than those recommended by university extension senices will result in increased yield and income. In addition to high rates of N, many producers feel that additional foliar fertilizer will further increase yield and quality of burley tobacco and result in greater revenue. Concerns with excessive N additions include improper curing, elevated levels of tobacco specific nitrosamines (TSNA's), ... |
462. Validating the Wisconsin P Index with Measured Runoff P Losses From Agricultural FieldsPhosphorus (P) indices have been developed by most states in the USA for use as planning tools to assess the risk of P loss and identify appropriate management alternatives to control these losses where needed. Little information is available on the relationshp between P index values and actual P runoff losses in the field. We compared annual P losses in runoff measured at 2 1 field or sub-watershed locations with Wisconsin P index values calculated for the same areas. The research sites include... |
463. Zone Delineation for Nitrogen ManagementManaging nitrogen through zone soil sampling has been shown effective in revealing residual soil nitrate patterns in North Dakota. Zone delineation has been constructed using several types of data, including yield maps, remote imagery, topography and soil EC sensor data. A study was conducted in North Dakota, Montana and Minnesota to evaluate zone delineation methods. Across the region, yield frequency maps, topography, remote inlagery and soil EC data were effective in helping to construct zon... |
464. A Different Approach to Managing Nitrogen in SorghumResearch conducted over the past fifty plus years has been used to develop a Nitrogen Fertilizer Recommendation "formula" for grain sorghum which considers factors such as Yield Potential, Residual Nitrate N in the soil Profile, the amount of N mineralized fi-om Soil Organic Matter and Previous Crop Residue, and other potential sources of N such as animal manure or N in irrigation water. The current formula used is as follows: N Rec = Yld x (1.6) - (20 x %SOM) - PNST - PCA - Manure N - Water N W... |
465. An Environmental Assessment of Sensor-Based Variable-Rate Nitrogen Management in CornIn order to address the problem of nitrate contamination of surface and ground waters, various methods have been used to try to account for spatial variability of N within agricultural fields. One approach to account for this variability and thereby reduce nitrate pollution is in-season site- specific N application according to economic optimal N rate (EONR). Recently, active crop canopy sensors have been tested for mid-season, on-the-go N fertilizer application in corn. This 2004 and 2005 stud... |
466. Assessment of the Combined Effects of Soil pH and Carbonates on Soybean Yield and Development of Iron Deficiency ChlorosisSoybean is extensively grown in areas of the Midwest where fields often have areas of acid to calcareous soils intermingled in complex spatial patterns. Soil pH is highly buffered by carbonates, and measured pH usually ranges from 7.5 to 8.3 depending on the concentration of C02 and other factors. Soybean grown on high-pH calcareous soils often shows iron (Fe) deficiency chlorosis (IDC). Symptoms of IDC include yellowing of interveinal areas of young leaves and, as the deficiency becomes severe,... |
467. Corn Hybrid Responses to Nitrogen Fertilizer RatesEfficient use of nitrogen (N) fertilizer is becoming increasingly important in modem corn (Zea mays L.) production due to rising nitrogen fertilizer prices and growing concerns about NO3- contamination of ground and surface waters. Interest has arisen in whether nitrogen management can be improved by choosing hybrids that respond better to nitrogen. In order to see if hybrids respond differently to varying rates of N fertilizer, we grew nine hybrids at five N rates for three years at Urbana: Ill... |
468. Corn Yield Response to Fall and Spring Applied Controlled- Release Urea vs. Spring Conventional UreaNitrogen (N) application to corn has been proven to increase yields, but concerns about nitrate-N in ground and surface water have led to investigation of controlled-release N fertilizer. The objective of these experiments is to compare corn grain response to controlled-release urea (ESN) and conventional urea. Two field studies are being conducted at two locations in Iowa and corn yield data will be reported from 2003-2005. All N treatments were hand broadcast in 30 lb N/a increments from 0 lbs... |
469. Corn Yield Response to Residual Forage Crop Rotation and Manure Amendment Effect in Potato RotationsAccurate prediction of multiple-year N availability froin organic sources is difficult and can complicate nitrogen management for producers using these sources. The objective of this study was to use corn yield and soil N monitoring to evaluate long-term nutrient availability from rotational systems on an irrigated Alfisol in central Michigan. Over a 5-year period, multiple crop sequences were grown with either annual liquid dairy manure at 12,260 L ha-' or conventional mineral fertilizer applic... |
470. Cropping Systems Management Effects on Soil N Mineralization DynamicsChanges in soil organic matter (SOM) content due to cultivation also impacts the amount of indigenous soil nitrogen (IN) supply. Crop management practices designed to achieve high yields also result in high residue inputs, which can contribute to SOM build up and enhanced indigenous N supply. The objective of this study was to evaluate the long term effect of crop rotation and nutrient management in conventional and intensive maize based systems on the change in soil N supply. Soil samples fiotn... |
471. Development of Field InSite as an Effective Nutrient Management ToolNitrogen. phosphorus, and potassium are essential nutrients for crop production. Crop nutrient management is critical to the success of any farming operation. Land stewardship is a concern for most producers as long as yields and profitability are not affected significantly. While farmers are eager to improve the efficiency with which they apply nutrients, maintaining expected crop revenue per acre is equally important. Higher fertilizer costs have increased the desire to find better ways to ap... |
472. Evaluation of the Illinois Soil Nitrogen Test in the North Central RegionData from 96 locations across the North Central Region was complied to evaluate the usefulness of the Illinois soil nitrogen test (ISNT) in identifying fields where corn will not respond to additional N fertilizer and predicting the yield optimizing N rate (YONR) for each field. The ISNT could not accurately predict non-responsive sites, nor could it predict YONR. Sub-setting the data based on soil drainage class and previous crop did not improve the predictive capability of the ISNT. The ISNT w... |
473. Fertilizer Industry Update- Price, Availability, HistoryThis talk will review world and local factors that have been affecting fertilizer demand, pricing, and supply. The speaker will review fertilizer trends and usage in the world markets as well as discuss trends in the U.S. fertilizer industry. Due to the proprietary nature of most of the information, a paper is not included in the proceedings. Select slides may be available upon request. however. ... |
474. Hypoxia in the Northern Gulf of Mexico- a 2006 UpdateBased on several science reports and opinions, hypoxia (dissolved oxygen of -Mexico was previously thought to be caused by excessive loads or discharge of nitrogen (N) - primarily as nitrate plus nitrite-N (hereafter referred to as nitrate-N), and exacerbated by fertilizer N inputs (CENR, 2000). These science reports estimated lhat about 90% of the nitrate load to the Gulf was from nonpoint sources in the Mississippi and Atchafalaya River Basin (MARB). They also estimated about 56% of the nitrat... |
475. Impact of Nitrogen and Sulfur Fertilization on Wheat Yield and Quality in 2006Historically, wheat has not responded to supplemental sulfur (S) on fine to medium textured soils with adequate organic matter. However, improved sulfur scrubbers in the industrial sector have decreased the amount of S contributed annually by rainfall. Annual S deposition in Ohio has decreased by 50% over the last twenty-seven years (NADP, 2005). This may lead to greater demand for S in Ohio crops. Recent Oho research showed a positive response to ammonium sulfate but did not have the parameter... |
476. In-Season Nitrogen Management for Sub-Surface Drip Irrigated CornIrrigation water and nitrogen @I) management for subsurface drip irrigated (SDI) corn was evaluated from 2004 through 2006 at the South Central Agricultural Laboratory of the University of Nebraska. SDI irrigation and N management strategies to increase both water and N use efficiency were compared to preplant N application for hrrow irrigation, commonly used in the area. Irrigation water levels of 100, 75 and 50% of measured evapotranspiration (ET) were applied with SDI, and N was applied in tr... |
477. In-Season Nitrogen Recommendations for CornMaking fertilizer N recommendations involves a great deal of guess work and uncertainty because much, essentially all, of the fertilizer N is applied before the crop is planted and the amount is based on estimated crop use from historical data. In addition, producers, consultants, and fertilizer dealers try to anticipate how much N might be lost because of untimely or excess precipitation or how much additional N might be required if the weather conditions are favorable. Sidedress and in-season... |
478. Manure Source and Rate Effects on Soil Test Levels and Corn GrowthNutrient management planning has become an important tool in an effort to improve water quality. In Wisconsin, nutrient management regulations are in the process of moving to a phosphorus (P) based standard. As such, P budgeting and the P index will greatly influence manure applications. Thus, there is a need to better understand how soil test P changes with respect to a P based manure application. In Wisconsin, only 60 % of the total P applied in manure is considered to be available to the crop... |
479. Nitrogen Fertilization for Wheat Grown on Wet SoilsKentucky wheat production has declined fiom 530,000 acres in 1996 to 320,000 acres currently. During this time, the state average yield has increased at a rate of approximately 1.5 bushels per acre per year reaching a record high of 71 bula this year (USDA NASS, 2006). While some of the increased yield can be attributed to genetic improvements, much of the positive yield response is due to producers removing marginal soil from production. With the projection of higher wheat prices, many Kentucky... |
480. Nitrogen Mineralization Estimates for N Rate SuggestionsTo improve the accuracy of N rate recommendations for corn, reliable estimates of soil N supplying capability are needed. The important influence of soil N supplying capability on estimating corn N needs is illustrated by a recent compilation of data on corn yield response to N fertilization fiom over 300 experiments in Illinois, Iowa, Minnesota, and Wisconsin showing that 50 to 70% of the observed corn yield was produced with N supplied by the soil alone (Sawyer et al., 2006). The soil availabl... |
481. Nutrient Uptake and Partioning by Soybeans in ManitobaSoybean plants were analysed for nutrient uptake and removal through the growing season. The 45 bufac crop took up some 200 lb Nlac and removed 88% in the grain, leaving little residual N for following crops in the surprisingly high C/N ratio leaf, stem and pod material. Typical rate of N, PzOj and K20 uptake during the growing season were 4, 1 and 4 lb/ac/day, respectively. Much K was lost from senescing leaves. Nutrient translocation from vegetative parts to seed was observed for N, P, K, S, Z... |
482. On-the-go Sensing Technology for Improved Crop Nutrient ManagementOne of the major objectives of precision agriculture technologies is the site-specific management of agricultural inputs to increase profitability of crop production, improve product quality, and protect the environment. Information about the variability of different soil attributes within a field is essential to the decision-making process. The inability to obtain soil characteristics rapidly and inexpensively remains one of the biggest limitations of precision agriculture. Numerous researchers... |
483. Periodic Deep Tillage of No-till Corn and Soybean Systems in Southern IllinoisLow organic matter and low available moisture supplying soils in southern Illinois lend themselves to no-tillage crop production, but concern about compaction and rooting depth have led some to employ the use of periodic tillage. A field study was conducted at two locations in southern Illinois between 2000 and 2006 to evaluate the effects of periodic deep tillage (ripping 16-18 inches [40-45 cm] with minimum surface disturbance style shanks) prior to corn or soybean production. Deep tillage occ... |
484. Short-Term Stability of Soil Test Phosphorus in Agricultural FieldsThe spatial and temporal stability of soil test values is important to the use of soil testing for nutrient management. A study was conducted to evaluate the spatial and temporal stability of soil test phosphorus (P). Five sites ranging in size fiom 9.1 to 10.8 acres were soil sampled in the same locations in a 60 X 60 ft. grid either three or four times over a two year period. Bray 1 -P values were similar or decreased over time while Olsen-P values at two of five sites decreased. One site show... |
485. Should We Abandon Soil Testing and Yield Goals in Estimating Nitrogen Rates for CornIf the prices of corn and fertilizer-N and the shape of the N response function relating crop yield to the amount of fertilizer used are known, calculating an economically optimal N rate (EONR) for maximizing the net return to applied N is straightforward: the EONR is the N rate at which no firher increase in net return occurs. In most cropping systems and under common price scenarios, crop yield at the EONR is within 95 to 99% of the maximum yield obtained for the specific management package. ... |
486. Silage Specific Corn Hybrids for Silage Production in KentuckyFour corn hybrid types at three plant densities and two nitrogen rates were evaluated for forage yield, forage quality and ensiled quality. The four hybrid types included nutri-dense (ND), waxy (WX), leafy (LF), and dual-purpose (DP); while the three target plant densities were 54 000, 68 000, and 81 000 plants ha; and the nitrogen rates were 134 and 224 kg ha". WX consistently had low forage and grain yields compared with the otl~er types. When averaged over nitrogen rate and hybrid: plant dens... |
487. Slow Release Nitrogen Fertilizer and its Impact on Sustainable Turf Grass GrowthThe methodology of this project aims at developing an efficient, yet effective, means of providing various nitrogen (N) fertilizer sources to turf grass with the ultimate goal of maintaining sufficient biomass production while minimizing the use of excess fertilizer that may eventually end up contaminating our groundwater and waterways. Nitrogen is the nutrient required in the largest quantity by plants, and also poses the greatest threat when nutrient leaching and water contamination are consid... |
488. Strip-Tilled Corn Responses to Deep Placement of Phosphorus and Potassium- 2005 UpdateReduced tillage systems modify some of the most important variables related with the plant-soil- weather environment and consequently affect the last expression of this relation: yield. A possibly more restrictive root growth scenario (due to lower soil temperatures and higher mechanical impedance), as well as pronounced horizontal and vertical stratification in nutrients within the soil profile (particularly for no-till systems) could lead to a reduction in root uptake of nutrients. This sit... M. Cánepa, T.J. Vyn |
489. Sulfur and Nitrogen Starter Fertilizer for Corn in Northern ClimatesThe combination of cool and wet weather in early spring can reduce the amount of S and N released in soil by decomposition and mineralization of organic matter, particularly in reduced- tillage or no-till cropping systems. Recent changes to S emission regulations have decreased the amounts of S that is deposited to the soil through attnospheric channels. Field studies were initiated in 2005 at five corn (Zea mays L.) sites in Michigan to evaluate the effects of S and N starter fertilizer on nutr... |
490. Tillage and Nitrogen Application Methodology Affects Corn Grain YieldMore efficient use of fertilizer nitrogen (N) is essential for improved yields and environmental stewardship. While university N recommendations for corn are based on observations typically made in conventional tillage systems, few universities have established research to evaluate if N recommendations should be different for alternative tillage systems. Generally spealung, no-till or minimum tillage systems have been identified as needing additional N to compensate for microbial immobilization ... |
491. Use of Yield Goals for Providing N Rate Suggestions- General ConceptsRecent studies in the North Central region have shown a poor relationshp between optimum yield of individual sites and optimum fertilizer N rate (Sawyer et al., 2006). The outcome has been the development of fertilizer recommendation approaches that do not consider site yield goal (Vanotti and Bundy, 1994a; Sawyer and Nafiiger, 2005). This causes one to ponder how so many recommendation programs utilizing yield goal were developed in the fist place and have continued in use for more than 40 year... |
492. Utilizing Existing Sensor Technology to Develop a Late-Season Critical Value for Spring Wheat ProteinA premium is paid to producers for spring wheat with a protein content greater than or equal to 14%. Obtaining that protein content can be problematic without proper nitrogen (N) fertilizer management. Sensor-based technologies have been used for predicting yield. The question is whether ths technology can be used to determine the protein content in-season for spring wheat. Field studies were conducted in South Dakota in 2003 and 2005. Five N treatments (0, 34, 65, 102, 136 kg N ha-') were appli... |
493. Utilizing the Greenseeker to Evaluate Spring Wheat Growth and YieldThere is currently little information on the use of existing sensor-based technologies for in- season application of nitrogen (N) to spring wheat (Triticttm aestivztm L.) in the northern Great Plains. Over the past decade researchers in the southern Great Plains have developed the Greenseeker as a tool for on-the-go N application to winter wheat. Field experiments were established in Brookings and Gettysburg, SD to evaluate the Greenseeker Hand Held optical sensor (NTech Industries, Ukiah, CA) ... |
494. What's New with Micronutrients in our Part of the WorldThe importance of micronutrients for production of a variety of crops in the North-Central region of the U.S. has been recognized for many years. When needed, these essential nutrients can have a substantial positive impact on production. However, neither the need for nor the importance of each micronutrient is universal across the reg~on. Importance (need) is greatly affected by crop. soil properties, and production environn~cnt. With traditional thinking over the years, thoughts have focused o... |
495. Nitrogen Fertilizer Efficiency in a Long-term Research TrialIn 1993, a long term crop rotation study (The Living Field Laboratory) was initiated at the W.K. Kellogg Biological Station, Hickory Corners, MI, designed to investigate the benefits of cover crops in various integrated systems compared to a conventional system without cover crops. Today, with the rising cost of production (i.e. energy and fertiliz er) and continued environmental concerns, there are strong incentives for corn pr oducers to accurately assess N requirements and improve fertilizer ... |
496. Field Measurements of Nitrous Oxide Emissions across a Nitrogen Fertilizer Gradient for Corn Cropping SystemsSignificant reductions in nitrous oxide (N 2O) emissions from corn (Zea maize L.) cropping systems may be possible by reducing N fertilizer i nputs with relatively little impact on crop grain yield or economic return. To te st this hypothesis, experiments we re conducted at 4 locations in corn production in Michigan in 2007. All sites were under a corn-soybean rotation. Prior to planting, six rates of urea fertilizer (0-200 lb ac -1) were broadcast and incorporated into four replicate plots (RCB... |
497. Skip-Row Configuration and Plant Density Effects on Sorghum Grain Yield and Yield Component in Southern NebraskaEqual spacing of sorghum rows typically results in the highest grain yield when soil water is adequate throughout the season, but skip-row plan ting may be a means to reduce water deficits during reproductive growth stages. We evaluated the effect of skip-row planting configuration and plant population density on grain yield, yield components and water use efficiency at five locations in a transect across southern Nebras ka where annual mean precipitation ranges from 300 to 900 mm yr -1. Three r... |
498. Corn and Soybean Grain Yield and Concentration of Potassium in Plant Tissues and Soil as Affected by Potassium FertilizationResearch in the Midwest has shown that K fer tilization tends to increase plant K uptake by corn and soybean and the K concentration of vegeta tive tissues. Several studies found that K fertilization usually increases the K concentrati on of vegetative plant parts, often regardless of the soil-test K (STK) level a nd grain yield response (Malla rino et al., 1999; Borges and Mallarino, 2000; Yin and Vyn, 2002a, 2002b; Borg es and Mallarino, 2003; Yin and Vyn, 2003). It is well known that the K co... |
499. Value of Tillage Practices and Nitrogen Rates for Corn ProductionMost N recommendations for corn (Zea mays L.) production in the U.S. Midwest do not consider tillage as a factor when an appropriate N rate is determined. Our objectives were to determine the response of grain yield and RTN to increasing rates of fertilizer N for corn grown in three tillage systems. Tillage by N rate experiments we re conducted at eight Central Illinois site-years at three locations and years (1998-2000). Tillag e systems employed were: zero-till, where no tillage was performed ... |
500. Effects of Phosphorus Fertilizer Rate, Timing, and Addition of Fertilizer Enhancer on Potato Yield and QualityPotato plants are very inefficient in their abil ity to utilize soil phosphorus (P) on some soils (Kelling et al., 1997). The optimum soil test P category for potato is more than three times greater than for other crops (Laboski et al ., 2006). Being a high value crop, potato growers generally tend to apply more P fertilizer than recommended because it is inexpensive insurance if a yield response to applied P would occur. State nutrient management regulation requires growers to write and follow ... |
501. Sustainable Vegetable Crop Production Using Vermi-CompostThis research intends to utili ze earthworm castings as an alternate nutrient source, especially nitrogen, for vegetable crop production. The experiment was conducted in the greenhouse and 'Mountain Fresh' tomato ( Lycopersicon esculentum Mill.) was used as the test crop. The main objectives were (1) to identify the optimum app lication rate of earthworm castings (EC) for tomato growth, and (2) to compare tomato res ponse under different treatments. Three different textural soils, namely sandy s... |
502. Plant Population Influences on Maize Physiological Responses to Nitrogen ApplicationPast genetic improvements in maize ( Zea mays L.) have led to the creation of modern hybrids that are increasingly tolerant to a variety of stresses and, in particular, to high plant populations. However, high plant densities can adversely a ffect overall grain yield due to greater intra- specific (within species) competition for lim iting resources. This competition increases barrenness and plant-to-plant variability for grain yield (GY CV) and other morpho-physiological traits. In this study, ... |
503. Evaluating the Removal of Corn Residue on Crop Production and Soil QualityRemoval for corn residue as a possible feedstock for the biofuels industry leaves many producers with a number of unanswered questions. These include what impact will this have on the following crop and also the impact on soil quality associated with this practice. A field study was established in 2000 to addr ess these and other questions. Experimental treatments include three corn residue removal levels (low, mid and high); corn harvested for grain and all residue remains on the soil surface,... |
504. Aerial Photographs to Guide Corn Fertigation DecisionsCorn producers with pivot irrigatio n have the potential to apply in-season nitrogen (N) fertilizer much more easily than their non-irrigated counterpa rts. A demonstration project was initiated in 2006 to take advantage of this potential. One advantage for in-season N application is that the risk of N loss prior to crop uptake is minimal. Another advantage is the opportunity to diagnose N n eed. A range of studies have shown that N need can vary widely from one field to another, as well as with... |
505. Using Reflectance Sensors to Predict Nitrogen Needs of CottonObjectives 1) Develop on-the-go N recommendations based on analysis of the reflectance sensor readings. 2) Determine the sensor model, height, and wa velength that give the best prediction for sidedress N. 3) Determine the best growth stag e for sensor-based sidedressing Relevance There is great spatial variability of N in the soil. Cotton fields that receive a blanket rate of nitrogen, ignoring the vari ability, will have areas of excessi ve growth. This unnecessary growth raises production cos... |
506. Management of Enhanced EfficiencyFertilizersPhosphorus generally occurs in soils as the anions H 2PO4- or HPO4-2, depending on the soil pH. These anions readily react with soil cations su ch as calcium, magnesium, iron, and aluminum to produce various phosphate compounds of limited wate r solubility. Crop recovery of applied P fertilizer can be quite low during the season of application. Specialty Fertilizer Products 1 has developed and patented a family of dicarboxylic co-polymers that can be used as a coating on granular or mixed into l... |
507. Swine Manure Applications for Soybean Production - Environnmental and Pathological ImplicationsSoybeans are leguminous plant sp ecies capable of fixing nitrogen (N) from the atmosphere to support their growth and development. Despite th e fact that soybeans can fix their own N, in a soil environment rich in inorgani c N they will scavenge for available N decreasing the level of root nodulation (Schmidt et al., 2000; Hester man and Isleib, 1991). Studies conducted to measure the impact of N fertilization of soybean s reveals that crop response to commercial N fertilizer does not result in ... |
508. Evaluation of the Greenseeker Active Sensor for Sugarbeet Cropping System Nitrogen ManagementThe application of adequate, non-excessive rates of N fertilizer to sugarbeets ( Beta vulgaris L.) continues to increase in importance with rising fertilizer costs and industry transitions from yield-based payments to payments weighted towa rd crop quality. The objective of this study is to evaluate the use of an optical sensor for its potential in assessing in-season sugarbeet N status, in-season yield prediction, and total N in foliage on day of harvest. Six N fertilizer treatments, from 0 to ... |
509. In-Season Nitrogen Management for Corn ProductionWater quality impairment related to nitrogen (N) continues to be a concern in Iowa, including the nitrate drinking water standard, USEPA proposed surface water quality nutrient criteria, and the Gulf of Mexico hypoxia. Addressing these issues could include strict guidance for N input to corn and resultant N use practices that require very high level of management and risk, with unknown economic consequences. Rate of N application is an important ma nagement factor in corn production related to n... |
510. Fertilizer Placement with Seed - A Decision AidBanding fertilizers with the seed at planting con tinues to be a popular option with producers in the Great Plains and North Central regions of the U.S. However, seed-placed fertilizer may limit germination/emergence of the seed/seedling. Nutrie nt source and rate are two factors affecting injury that are relatively simple to manage. Unfortunately, many crop producers and advisors have few rate guidelines for the many crop by fer tilizer combinations that are common to the region. The objectives... |
511. Triple-Stacks, Genetics, and Biotechnology in Improving Nitrogen Use of CornGenetic improvement in N use efficiency (NUE) is a clear strategy fo r enhancing yield and fertilizer N management of corn ( Zea mays L.), and has been the subj ect of our ongoing research. Calculation of the N requirement (N fertilizer usage/grain yield) based on statewide average grain yields and fertilizer sales shows a stead y decrease since the mid 1980's, suggestive of a genetic improvement in N use. Direct comparis on of the response to N for a 1980�۪s hybrid with its modern counterpar... |
512. Factors Affecting the Relative Benefit of Deep-banding versus Broadcast Application of Phosphorus and Potassium for Corn and SoybeanScientifically based recommendations concerning the choice of deep banding versus traditional broadcast application of phosphorus (P) and potassium (K) for corn and soybean production in conservation tillage systems have been hampered by insufficient research and inconsistent results. Even when the decisi on is made (e.g. by strip-tillage corn farmers) to go with deep- banding of P and K, numerous questions remain about fertilizer rates, optimum deep-banding depth and frequency, whether to have ... |
513. Manure Application Technology and Impact on Nitrogen DynamicsA field study was carried out ne ar Elora, Ontario to assess the impact of manure application timing and method on ammonia volatilization a nd nitrogen availability to the crop. A novel method was developed and calibrated for quan tifying ammonia volatilization using passive dosimeter tubes, which promises to provide an economical alternative to other methods. Ammonia loss was negligible from injected manure treatments, and when manure was incorporated immediately it had smaller losses th an wh... |
514. NUE in Practice: Will N-efficient Corn Hybrids Sell?Efficient use of nitrogen (N) fertilizer is becomi ng increasingly important in corn production due to rising N fertilizer prices and growing concer ns about N contamination of ground and surface waters. Seed companies are also beginning to develop hybrids with N use efficiency (NUE) improved through trait introduction. The introduc tion of such hybrids will bring new questions about the value of higher NUE, and about risk ma nagement associated with decreasing, or not increasing, N use rates as... |
515. Nitrogen Recalibration for Wheat in North DakotaThe general formula for determining N fertilizer ra te in North Dakota for about thirty-five years has been N-rate = (2.5 X Yield Potential (or Yield G oal) less credits from previous crops and soil test nitrate-N from a 2-foot soil core composite. Historically high fertilizer N costs and the ability to fertilize within fiel ds rather than whole field N management has resulted in a reexamination of N calibration data, and an effort to expand the modern N calibration database with new field exper... |
516. Cover Crop Management for Soybean Iron Deficiency ChlorosisIron Deficiency Chlorosis (IDC) has been a s oybean production in the Upper Midwest for many years. A study was conducted in 2006 and 2007 to determine the effect of cover crop management under increasing soil nitrate-N concentrations. The study was conducted at two locations each year with histor ies of IDC. The treatments incl ude nitrogen rates of 0, 100, and 200 pounds N per acre applied as Ur ea with and without an oat cover crop. The oat cover crop was planted at a rate of 1 bushe l per ac... |
517. Soil pH and Manganese Effects on Roundup Ready SoybeansSoybean 'flas'h is a general yellowing of th e upper soybean canopy thought to be associated with high rates of glyphosate and reduced levels of manganese (Mn) with glyphosate-resistant soybeans. Several field sites varying in soil Mn levels and some with within field variable pH levels were evaluated between 2004 and 2006 for re sponsiveness of soybeans to glyphosate rate and Mn treatments. The objectives of this study were to 1) evaluate the effects of foliar applied Mn and soil applied Mn on ... |
518. Predicting Relative Yield of Corn in Indiana Using an Active SensorFine-tuning N fertilization is important for impr oving the economic and environmental impact of corn production. This importance is highlighted by ever rising fertilizer prices and increased public scrutiny. Reflectance measurements usi ng an active sensor during the growing season may be useful for determining the need for additio nal N. This is the second year of a multi-year study to evaluate canopy reflectanc e as an N management tool across a variety of Indiana soil types. The objectives o... |
519. Starter Potassium for Corn: Why and WhenStarter fertilizer application can complement broa dcast P and K fertilization for corn and other crops. Questions about its use relate mainly to the conditions in which it is most effective (such as soil-test level, tillage syst em, and broadcast fertilization rates among others), application methods and rates that do not damage seedlings, and nutrient ratios. Many studies in Iowa and the Midwest have shown that starter mixtures (usu ally N-P or N-P-K) often increase early corn growth. Corn yie... |
520. Delayed-Release Nitrogen Fertilizer Effects on In-Season Soil Nitrogen for Michigan Sugarbeet ProductionDelayed-release N fertilizers have received attention for Michigan sugarbeet production as producers seek to improve the timing of N ava ilability to better match plant demand and to maximize plant N use efficiency. The N release ch aracteristics of these products are particularly important in sugarbeet production, where excessive N availability late in the season can have adverse impacts on crop quality. The objective of this research was to evaluate delayed-release N fertilizer sources, alone... |
521. Effect of Phosphorus and Potassium Fertilization on Corn Development and Root Distribution in Conservation TillageIn conservation tillage systems, like no-till (NT) and strip-till (ST), phosphorus (P) and potassium (K) typically become vertically and/or horizontally stratified in the soil. This stratification has the potential to make P a nd K less available and to limit corn yield. The objective of this study is to determine the infl uence of tillage and P and K placement and rate on soil P and K content, soil water status, root and shoot development, and grain yield of corn. The experiment was arranged i... |
522. Foliar Manganese and Glyphosate Formulation Yield Effects on Glyphosate-Resistant Soybeans in OhioIn order to address the potential problems associated with glyphosate and manganese applications to glyphosa te-resistant soybeans (Glycine max [L.] Merr.), an experiment with varying glyphosate and manganese micronutrien t formulations and application timing was designed and carried out on two locations in Ohio to test effects on soybean yield. At the location in northwestern Ohio, th e yields for all of the manganese-treated plots were significantly higher ( P=0.1) than the untreated plots, re... |
523. Impact of Biofuel Crops on U.S. Agriculture: An OverviewBiofuel crops are having an impact on prices of commodities, land use, and environmental factors such as water quality, biod iversity, etc. There are critical linkages today that result in the phenomenon of oil and corn prices moving in lockstep. We also see that limited cropland leads to tradeoffs between different crops that aff ect not only food and feed production, current corn based biofuel production but also future cellulosic production. The current and potential impact of biofuels on the... |
524. Enhanced Efficiency Nitrogen Fertiizers Release in an Illinois SoilThe release rates of ammonium and nitrate from applications of enhanced efficiency nitrogen fertilizers to soil is not well understood. A better knowledge of th e soil processes involved with N release could allow for greater acceptance of these fertilizers. The objective of this study was to compare traditional quick release fertilizers w ith enhanced efficiency nitrogen fertilizers to examine their release rates. Th e fertilizers chosen were urea and a polymer-coated urea, which were applied t... |
525. Nitrogen Availability of Treated and Raw Dairy ManureThere is minimal information on the nitrogen (N) availability and composition of treated manures. Knowing how N availability differs w ith manure treatment will result in better N crediting guidelines. Raw dairy manure and anaer obically digested manure were incubated with five typical Wisconsin soils for 112 d. Net N mineralized from the different N sources were compared. Nitrogen mineralizatio n differed by manure type and also by soil. Overall, the digested slurry and the digested separated l... |
526. Nitrogen Recalibration for Wheat in North DakotaThe rise in grain prices and fertilizer costs, as well as the need for more soil-specific recommendations has spurred recent research into N response of wheat in North Dakota. Combining data from 1970 to 1990, together with recent studies has shown that new recommendations are in order. There is a rela tionship of wheat yield to available N. The relationship is better when residual soil nitrate is considered. Different areas of the state partition out with different response curves. Using the '... |
527. Evaluation of Nutrisphere-N as aSoil Nitrification and Urease InhibitorNutrisphere-N is a fertilizer ad ditive, which is claimed to prev ent nitrogen loss from soil through the inhibition of urease and nitrif ication. The objective of this study was to evaluate the effects of Nutrisphere-N on urease, nitr ification, and ammonia volatiliza tion from soil under controlled condition. Nutrisphere-N was mixe d with urea solutions or impregnated on urea granules and before application to soil. In the three experiments conducted, adding Nutrisphere-N had little or no effe... |
528. Biomas Removal: Effect on Soil Nutrients and ProductivityInterest in renewable alternatives to fossil energy has increased. There is also a growing awareness of the impact of greenhouse gas emission on global climate change. Crop biomass can be used to make liquid fuels like ethanol. These cellulosic materials are also potential feedstock for controlled combustion substituting fo r natural gas or coal. There are a wide range of potential feedstocks, trees, perennial grasse s and crop non-grain biomass (or residues.). Particularly in the Corn Belt, cor... |
529. Recent Perspectives for Starter Fertilizer Use on Corn in MinnesotaApplication of fertilizer with the seed at planning has been a popular choice for Minnesota corn farmers to get their crop off to a fast start. Traditionally the salt index of a fertilizer has been important in farmers' management decisions. A research study was conducted at six locations on fine and coar se textured soils around Minnesota. Three fertilizer grades, 4-10-10, 10-34-0, and 3-18-18 were compared at two rates and in three placements relative to the seed. Nitrogen (N) and phosphorus (... |
530. Weed Control Timing Effects on Corn Yield Response to NitrogenNitrogen (N) rate guidelines for corn are under c ontinued scrutiny to maximize N use efficiency in order to minimize potential N losses to th e environment while maximizing economic returns to growers, especially with significant N fertilizer price increases in recent years. In-season crop stress can potentially affect corn N needs for optimum production. Recently, postemergence weed control has become more common with th e availability of glyphosate resistant corn hybrids. Delaying weed contro... |
531. Foliar Fertilization and Fungicide Application for SoybeanConcerns over fungal diseases in soybean have renewed interest in applying pesticides for disease control with the goal of increasing grain yi eld. Interest has especially been sparked by discussions of the possibility of Asian Soybean Rust (Phakopsora pachyrhizi) spreading north to the North Central region. Because of increasing prices of soybean grain and traditional fertilizers, many Midwest grower s are considering mixing fluid fertilizers and fungicides for foliar application to soybean. Ex... |
532. Incorporating Cover Crops into No-till Production SystemsAlthough no-till soil management has many benef its, including protecting the soil from erosion, improving soil organic matter, and improving soil moisture storage, depending on environmental conditions there could be a number of potentia l problems. Implementation of no-till soil management in eastern South Da kota can lead to wet and cold soils at the time of planting. Cover crops have the potential to utilize exce ss soil moisture and improve soil conditions at planting. A field experiment wa... |
533. Crop Residue Removal Effects on Soil PropertiesThree large challenges facing mankind are the n eed to feed a rapidly growing population, increasing concentration of greenhouse gases in the atmosphere, and reliance on fossil fuels. Expectations from agriculture include produ ction of food and fiber to meet demands, management of agricultural systems to sequester carbon and redu ce emission of other greenhouse gases, and provision of feedstock for a rapidly expanding biofuels industry. Some discussions involving use of crop residue for biofue... |
534. Organic Farming in Nebraska: Establishing Organic Research for the Organic Farming CommunityFour sites in Nebraska were developed to have land available to conduct research on certified organic land. All sites will be certified organic by the end of 2008. The goal of the project is to conduct research relevant to the organic farmi ng community and not to compare organic systems with conventional systems. Resear ch is being conducted on the use of flaming to control weeds, winter wheat variety development and selection for the organic market, variety testing of organic winter wheat, pro... |
535. Nitrogen Management for Soft Red Winter WheatSoft red winter wheat was grown wi th various rates of four N materials, ammonium sulfate, urea, urea-ammonium nitrate and ESN, for harvest years 2004 through 2007. In all studies 21 lbs N/a was applied at planting. Over th ese four years top wheat yields were produced with 60 or 90 lbs topdress N/a depending on year. Av eraged over the four years 90 lbs N/a resulted in 1.6, 1.0 and 2.2 bu/a more yield than 60 lbs N/a for urea, UAN and ESN. This difference was neither significant nor economical.... |
536. Corn and Soybean Response to Starters After Broadcast Fertilizer ApplicationCorn response to fertilization and placement methods has always been a subject of interest and extensive research; however studies on soybean response to placement have been limited in Kansas. The objective of this study was to evaluate the effect of starter and broadcast fertilizer application on corn and soybean in a typical corn-soybean rotation in Kansas. Grain and seed yield, early growth, nutrient concentration and uptake were evaluated over eight site-years trials in Kansas for both corn ... |
537. Recoverable Yield: A New Component for Improving Algorithms Used For Sensor Based Nitrogen Management In WheatIncreased interest in N management over the past decade has stimulated interest in using optical sensors to predict N needs in a number of crops. Many universities have created N recommendation algorithms for winter wheat, with slightly differing approaches. While many university algorithms operate under the assumption that 100% of the yield potential difference between the N rich strip and the farmer practice can be recovered, we believe that this will not always be possible. The objective of ... |
538. Assessment Of Enhanced Efficiency Urea Products On Maize In MissouriUrea is the most commonly used N fertilizer worldwide, but can be easily lost to the environment through ammonia volatilization. Enhanced efficiency fertilizers (EEF) have been developed to help prevent these losses. Field studies were conducted from 2009 to 2011 on a Mexico silt loam (fine, smectitic, mesic, Vertic Epiaqualf) to determine the efficacy of five EEF urea products compare to untreated urea when surface applied to no-till maize (Zea mays L.). Treatments included untreated urea, Agro... |
539. Uptake and Leaching Potential Of Potassium And Sulfur When Split Applied For Corn on Irrigated SoilCoarse textured soils used in irrigated agriculture often face nutrient losses through the soil profile due to low cation exchange capacity (CEC). Split fertilizer application on sandy soils has been recommended for the corn crops in MN to avoid the leaching of fertilizers nutrients. Our study aimed to look at the potential for potassium and sulfur to be taken up or leached out in corn production. Two K and two S fertilizers studies were set up in Minnesota on coarse irrigated soils. Each site h... |
540. Phosphorus Placement For Corn, Soybeans, and WheatRoot-Soil Interface Transport Pathways Three mechanisms are commonly cited for how nutrients reach plant roots: 1) root interception, 2) mass flow, and 3) diffusion. Root interception occurs when a plant root, as it grows, comes into direct contact with a nutrient. Quantities of nutrients reaching plant roots in this manner are estimated to be proportional to the volume of soil occupied by roots (Barber et al., 1963). For instance, if roots occupy one percent of the soil volume, then the quantit... |
541. Hybrid and Plant Density Effects on Nitrogen Response In CornThe development of corn hybrids that may be improved for nitrogen use efficiency along with the emphasis on higher plant density for maximum yields of modern hybrids have raised questions about interactions between N rate and plant density. We planted four hybrids (Pioneer 33D49, 33K44, 33W84, and 34F07) to represent a range of responses to N rate and plant density at four sites in Illinois at combinations of densities of 44,460, 83,980, and 123,500 plants ha -1 and N rates of 0, 90, 179, and 26... |
542. Use of Enhanced Efficiency Nitrogen Fertilizers To Reduce Leaching And Volatilization LossA laboratory study was conducted to explore interactions of N source and treatment with precipitation events on a coarse-textured soil. Nitrogen sources included urea-ammonium nitrate solution (UAN), UAN with additives of either nitrapyrin (Instinct �) or a carboxylated polymer (Nutrisphere-N�), or a polymer-coated dry urea (PCU) (ESN�). These products were applied to soil chambers which allowed measurement of ammonia (NH 3-N) volatilization or nitrate leaching over 31 days. Precipitation ... |
543. Nitrous Oxide Emissions From Nitrogen Fertilizers In IllinoisNitrous oxide (N 2O) has a large global warming potential (GWP). Agricultural applications of nitrogen (N) contribute to N 2O emissions but it might be possible to mitigate such emissions through different N sources. We investigated the potential for anhydrous ammonia (AA), urea, and polymer coated urea (ESN) to mitigate N 2O emissions while enhancing corn (Zea mays L.) production. This three-year study was conducted in Champaign County, Illinois on highly productive mollisols during 2009 to 201... |
544. Use Of Corn Height To Improve The Relationship Between Active Optical Sensor Readings And Yield EstimatesPre-season and early in-season loss of N continues to be a problem in corn (Zea mays, L.). One method to improve nitrogen use efficiency is to fertilize based on in-season crop foliage sensors. The objective of this study was to evaluate two different ground-based, active-optical sensors and explore the use of corn height with sensor readings for improved relationship with corn yield. Two different ground-based active-optical sensors (Greenseeker�, Trimble, Sunnydale, CA; and Holland Crop Cir... |
545. Poly-Coated Urea Responses For Winter Wheat In The Northern PlainsManaging nitrogen applications for winter wheat production and quality includes limiting N volatilization with surface urea applications in the northern Great Plains. Two winter wheat sites located in central and western (W) South Dakota were established in the fall of 2011. Treatments were broadcast poly-coated urea (ESN) and urea at different blend proportions applied at rates of 0, 40, 60, 80, and 100 lb N/a and two timings (fall and spring). An additional winter wheat site was established in... |
546. Effect of Biosolids Application On Plant Available NutrientsBiosolids are a by-product of municipal wastewater treatment process which is extensively treated to meet all applicable federal and state regulations so that they can it can be safely applied to land. Approximately, 7.9 million dry metric tons of biosolids are produced annually in the United States (U.S.) and over 55% of this amount is beneficially utilized through land application (NEBRA, 2007). Farmland application of biosolids is considered to be one of the most economical and environmentall... |
547. Corn Hybrids With Contrasting Root Systems: Response To Soil And Fertilizer PhosphorusWith current corn genetic improvements for water-limited scenarios, root system architecture and growth are being considered which may affect overall nutrient uptake particularly for immobile nutrients. The objective of this study was to evaluate plant response and phosphorus uptake with contrasting, generally shallow and generally deep rooted corn hybrids. Over the two years there were a total of seven sites, two sites in 2011 and five sites in 2012. The sites are all rain fed except for three ... |
548. Consequences Of Shallow NH3 Placement And Timing On N Use Efficiencies In Corn ProductionA field study in west-central Indiana was conducted to investigate the effects of shallow anhydrous ammonia (NH 3) placement and timing on N use efficiencies in a conventionally tilled corn production system following soybean crop. The spring NH 3 was applied either pre-plant (6- inches offset from future corn row) or side-dress (at mid-row position) at different rates (0, 80, 130 or 180 lbs N acre -1). Aboveground biomass harvest and combine harvested yield were used to determine N recovery, N ... |
549. What Do Recent Plant Tissue Analysis Surveys In Soybean And Alfalfa Tell Us?Plant tissue analysis surveys were conducted for soybean in 2011 and 2012 and alfalfa in 2010 and 2011. Seventy-three random alfalfa fields throughout Wisconsin were sampled at bud to first flower prior to first or second cutting. For alfalfa, 49% of samples were low in potassium (K) based on sufficiency levels, and results were related to soil test K level and amount of K applied. Sulfur (S) was low in 62% of all alfalfa samples. This result was surprising, as only 18% of the fields were consid... |
550. Testing Field-Moist Soil For Potassium And Other Nutrients - What's It All About?Potassium (K) is present in the soil in water-soluble, exchangeable (both readily available for crops), non-exchangeable or fixed (may become available over time), and mineral (unavailable) forms. Estimates of soil exchangeable K with the ammonium-acetate and Mehlich-3 extractants from air-dried or oven-dried soil samples are the most widely used soil-test methods for K. These methods provide comparable K test results, and are suggested for the north-central region by the North-Central Regional ... |
551. Responses To K Fertilizer On High Testing SoilsSoil testing is the foundation for nutrient management decisions, and is based test method research and calibration models in the Midwest has been generated in the public sector by Land Grant Universities (LGU) over the last 75 years. The successes of soil testing over the past three decades has been in large part been due to the inherent value of the testing method, monitoring over time, and adoption of precision Ag technology. Soil testing for potassium (STK) in the Midwest, is based on the co... |
552. 4R Nutrient Stewardship: A Component Of Agricultural Non-Point Source PolicyA challenge of agriculture is to increase production and feed the world without adversely affecting the environment. Fortunately, there is an immediate connection between applying the 4Rs (the right fertilizer source at the right rate, the right time and in the right place) and their beneficial impacts on crop performance, soil health and decreased environmental pollution. While any approach to addressing non-point source nutrient losses from agriculture must involve fertilizer best management ... |
553. Response Surface Models Of Subsoil K Concentration For Loess Over Till Soils In MissouriCrop uptake of potassium (K) has demonstrated sensitivity to subsoil variation in K content. This fact has not been sufficiently considered in K management strategies in part due to logistical difficulties in sampling spatially variable subsoil K. We propose a simplified soil factorial model, a response surface, to enable site-specific accounting of whole root zone K supply for loess over till soils. We compared the performance of two peak functions and a non-parametric local regression procedu... |
554. Winter Rye Cover Crop Biomass Production, Degradation, And N RecyclingWinter rye (Secale cereale L.) as a cover crop can take up residual inorganic N between annual row crops and therefore be used to help reduce NO 3--N loss from fields and movement to water systems. However, does the rye N uptake affect N recycling to soil and add to plant available N? The rye carbon:nitrogen (C:N) ratio could also influence N recycling. The objectives of this study were to evaluate rye biomass degradation and N recycling after spring rye termination in a no-till corn (Zea mays L... |
555. Understanding Components To High Yielding Soybean Production SystemsThe increasing amount of products and techniques available to producers, coupled with increasing input costs, lends greater importance to the evaluation of management options for optimization of yield and economic return. This study was conducted to determine: 1) soybean yield potential when five additional inputs are combined in a high-intensity production system; 2) soybean yield impact of each additional input when removed from the high-intensity system; 3) soybean yield potential of each add... |
556. Assessing Nitrogen Use Efficiency Of Maize On Highly Productive Irrigated Sandy Soils As Affected By Three Nitrogen SourcesIrrigated soils in Minnesota account for only 500,000 acres, but these acres are some of the most productive and environmentally sensitive areas in the state. Ground water is the major source of drinking water in the sandy areas of Minnesota, so obtaining information on nitrogen use efficiency is critical for corn (Zea mays L.) grown on these soils. Slow release urea products have the potential to increase nitrogen (N) use efficiency by releasing N at a time when crop demands are highest. Two su... |
557. Crop Sensor-Based N Rates Out-Performed Producer-Chosen N RatesOptimal N fertilizer rate for corn (Zea mays L.) and other crops can vary substantially within and among fields. Current N management practices do not address this variability. Crop reflectance sensors offer the potential to diagnose crop N need and control N application rates at a fine spatial scale. Our objective was to evaluate the performance of sensor-based variable-rate N applications to corn, relative to constant N rates chosen by the producer. Fifty-five replicated on- farm demonstratio... |
558. Plant Availability of Phosphorus From Struvite Produced During Corn Bioenergy ProcessingThere is strong interest on recovering nutrients from the waste stream of industrial processing of crop biomass for bioenergy so they can be efficiently utilized as fertilizer materials. Phosphorus (P) can recovered as struvite [NH 4Mg(PO4).6H2O] from the aqueous stream. A low P water- solubility in struvite and previous research with the pure mineral or struvite precipitated from liquid animal manure suggest a slow-release of P from struvite. However, a recent short-term greenhouse study in Iow... |
559. Continuous Corn Production As Affected By Starter Fertilizers Containing Nitrogen, Phosphorus, and SulfurCrop rotations in the Midwest have changed from the traditional corn-soybean rotation to more corn-intensive rotations. Due to the expanding demand for corn to supply the ethanol industry and the increasing insect and disease challenges facing soybean producers, some farmers are switching to a corn-corn-soybean rotation or for some, continuous corn. These rotations produce large amounts of biomass (corn stover) that often remain on the soil surface with present day tillage systems. This is good... |
560. Organic Nutrient And Weed Management With Sweet Corn On Sandy SoilThe Central Sands region of Wisconsin is host to commercial-scale vegetable production, requiring intense nitrogen (N) fertilization. The limited nutrient holding capacity and minimal organic matter content of sandy soils in the Central Sands contributes to water nitrate contamination. Organic management may help to alleviate problems associated with leaching by increasing organic matter and nutrient retention in this soil. For organic agriculture to be feasible in this region, organic N inputs... |
561. Evaluation Of Macro and Micronutrients For Double-Crop Soybean After WheatWith double crop soybean production, fertilizer is typically applied prior to planting wheat and intended for both crops; when wheat nutrient removal is higher than expected this may limit nutrient supply for the following soybean crop. The objective of this study was to evaluate the response of soybean grown after wheat to soil-applied and foliar fertilization, including changes in tissue nutrient concentration, and response in grain yield. Four sites were established in 2011 and 2012. All site... |
562. Predicting Fertilizer Nitrogen Response In Corn Following AlfalfaCorrect prediction and application of alfalfa N credits to first-year corn can reduce fertilizer N costs for growers, reduce over-application of N, and reduce the potential for water contamination. For decades, researchers have found that first-year corn following alfalfa often requires no fertilizer N to maximize grain yield. However, a review and analysis of nearly all the research on this topic in North America and Spain (442 site-years of research) indicates that corn following alfalfa can r... |
563. Soil Nitrogen Mineralization In Different Tobacco Tillage-Rotation SystemsSoil nitrogen mineralization, the microbial and biochemical transformation of organic N (e.g. proteins) into inorganic N compounds (e.g. NH 4+, NO3-), is of central importance to the nitrogen management and productivity of agricultural soil. Effects of different burley tobacco tillage and crop rotation systems on net soil N mineralization were studied, their correlation with soil organic matter, and the vertical distribution of mineralized N. Net soil N mineralization was measured by long-term ... |
564. Considerations for Development of Optical Sensor Based Nitrogen Recommendation Algorithms for CornOptical sensor technology in Kansas has been used on winter wheat and grain sorghum with great success for predicting N fertilizer needs early in the growing season. However with both crops, there is a required minimum period of growth required before optical sensors can accurately detect N deficiencies. In both cases the target crop needs to have entered a period of vegetative growth where N uptake and utilization is increasing. In the case of wheat that generally corresponds to the Feekes 4 t... |
565. Agronomic and Environmental Assessment of Cover Crops in IllinoisCrop production systems have been changing for thousands of years and new ideas and practices are being implemented every day. In recent years, the practice of cover cropping systems has come into the spot light, and though research has been in effect, the practice has been slow to take root for producers in Illinois. Benefits of cover crops primarily center around increases in soil organic matter, which can lead to higher soil productivity, but the long-term agronomic, environmental, and econom... |
566. Crop Yield Relationship to Remote Sensing Data Using Intensified Weighted Nonlinear Regression ModelsYield prediction is important for making in-season agronomic input decisions as well as for greater logistical decisions. In predicting the crop yield based on ground-based active optical sensing data, the ordinary statistical unweighted linear or nonlinear regression models are the most popular choices. However, these unweighted models may not be accurate enough for practical use because they are based on the assumption that each data point for regression is obtained with equal precision and t... |
567. Adaptive Nitrogen Management(Blank Page for Notes) ... |
568. The Nitrogen Index as a Tool to Reduce Nitrogen Loss to the EnvironmentContinued population growth creates a need for increased productivity of agricultural systems around the world. Increased agricultural productivity will be needed to support a population that is anticipated to have an additional 2.5 billion people by the year 2050. Nitrogen was part of the 20th century�۪s green revolution. Nitrogen continues to be essential for the viability and sustainability of agricultural systems that are important for feeding the growing global population. It is well kno... |
569. Corn and Soybean Response to Phosphorus Placement under Minimum Tillage SystemProducers often question the need for better fertilizer placement methods in reduced tillage systems. The objective of this study was to evaluate the effects of different placements and rates of phosphorus (P) fertilizer for corn (Zea mays) and soybean (Glycine max). The study was conducted at 3 locations from 2005 to 2012 (8 years). This paper presents results from one irrigated location. Tillage system was strip till before planting corn; and soybean was planted without previous tillage. Fert... |
570. Nebraska's Natural Resources Districts: Experiences in Managing Nitrate in Ground WaterNebraska's 23 Natural Resources Districts (NRDs or Districts) were formed in 1972, and are quasi-local entities which are charged with various responsibilities in managing the State's soil and water resources. The Districts are governed by locally-elected Boards of Directors, managed by professional staff, and have independent taxing authority. They have broad responsibilities in ground water quantity and quality management, and one of the major efforts NRDs have engaged in over the past several... |
571. Using Soil and Tissue Testing to Predict Soybean Yield Response to Foliar Applied Micronutrients in IowaPrior research with foliar application of micronutrients for soybean has shown inconsistent yield responses in Iowa and the western Corn Belt. Iowa has no interpretations for soil or tissue tests for micronutrients in soybean. This study's objectives were to evaluate soybean plant-tissue and grain yield responses to foliar application of boron (B), copper (Cu), manganese (Mn), and zinc (Zn) in Iowa. There were 22 field trials in 2012 and 21 in 2013, which were established in 20 counties and incl... |
572. Correlation and Calibration of the Mehlich 3 P Soil Test for Soybeans in KansasKansas currently uses the Mehlich 3 soil test for P, with a general P soil test (STP) critical level for all crops of 20 ppm (colorimetric). This critical level was established based on field research primarily with wheat in 2003. A review of the limited research data available from Kansas suggests that soybeans may not require as high a STP level as wheat for optimum yield. Therefore the objective of this study is to determine what the appropriate critical STP level is for optimum soybean prod... |
573. Nitrogen Timing and Nitrification Inhibitors for Corn in KansasAnhydrous ammonia is a common Nitrogen (N) source used for corn production in Kansas. Two common mechanisms of N loss in corn production in Kansas soils are denitrification and leaching. By minimizing these losses, producers can maximize yield with lower input use and have less impact on the environment. Time of application, particularly fall vs. spring application can have significant impact on N loss, particularly in some soils. The use of nitrification inhibitors (NI) with anhydrous ammonia ... |
574. Nitrogen Rate Revisions for Corn in North DakotaNitrogen rates in North Dakota have been based on a yield-goal or yield-potential formula for over forty years. The currently published formula (Franzen, 2010) is: Recommended N rate = (Yield Potential, bushels per acre) X 1.2 less N credits from previous crops and soil test nitrate to 2 feet in depth. A yield-based strategy was practical when N costs were relatively low and yields in North Dakota were at most 100 bushels per acre. However, due to improved germplasm developed at North Dakota Sta... |
575. On-Farm Assessment of Nitrogen Use and Management in Irrigated Corn Production in NebraskaHigh-yield irrigated crops have large nitrogen (N) requirements. For example, N uptake of a corn crop that yields 207 bu ac -1 (~13 t/ha) is about 180 lb N ac-1 (200 kg N ha-1). The amount of N that is not provided by indigenous sources (mineralization of previous crop residue and soil organic matter) needs to be supplied by crop producers through N fertilizer. High-yield irrigated corn accounts for 74% of total annual corn production of 1260 million bushels in Nebraska. With approximately 70,00... |
576. A Look at West, Texas(Blank Page for Notes) ... |
577. The Impacts and Magnitude of N Loss from Midwest Cropping Systems: What can we do about it?(Blank Page for Notes) ... |
578. Sulfur Cycling from Corn in Corn-Corn and Corn-Soybean RotationsSulfur fertilizer requirements for corn grown on medium and fine textured soils have increased over the past ten years. The effect of sulfur rate and timing on the potential for sulfur cycling and carryover within a two year crop rotation, corn-corn and corn-soybean, were studied. Sulfur was applied as ammonium sulfate on the soil surface at planting and the V3-V5 growth stages at rates of 0, 10, 20, 30, and 40 lbs of S per acre during the first cropping year. Each plot was divided in two prior ... |
579. Quantifying Risk in Nitrogen Management through On-Farm EvaluationsThe process of nitrogen (N) management in corn (Zea mays L.) production is often reduced to finding ways to manage various risks. These risks include common difficulties of quantifying soil N availability, avoiding N fertilizer losses, and predicting the impact of weather before and after fertilizer applications. This poster provides a synopsis of several recent on-farm evaluation studies conducted across Iowa. These studies were designed and executed to identify management, soil, and weather f... |
580. Soil pH and Crop Response to Lime Source and TillageAg lime recommendations are based on soil pH, buffer pH, and neutralizing index or effective calcium carbonate equivalent (ECCE) of the lime to be used (Laboski and Peters, 2012). Determination of neutralizing index may vary by state and is often codified in state regulations related to the sale of ag lime. In Wisconsin, the neutralizing index of a lime is a function of purity (calcium carbonate equivalent) and fineness (particle size) (Schulte et al., 2005). Pelletized lime is typically calciti... |
581. Nitrogen Loss from Sprinkler Applied Beef Feedlot EffluentLoss of nitrogen from sprinkler applied beef feedlot effluent can be costly for both the producer and the environment. Sprinkler application of effluent is common throughout the Great Plains, though little work has focused specifically on N losses from beef feedlot effluent. We quantified ammonia (NH 3) and nitrous oxide (N2O) losses from beef feedlot effluent applications under field conditions including variations in soil pH, soil water content, ammonium (NH 4+) concentration of the effluent, ... |
582. Soybean Production Research: A National ApproachU.S. soybean growers are looking for alternative methods to increase soybean yields and recent increases in commodity prices have given producers more freedom to invest in additional crop inputs or products. Unfortunately, quality data from studies addressing multiple contemporary inputs is scarce. The objective of this work was to evaluate the effectiveness of combined soybean inputs on seed yield. These high input systems were tested in six states to evaluate their value across a broad geograp... |
583. Hybrid, Plant Population, and Nitrogen Interactions in CornCharacterizing hybrids by their response to both plant population and N response will be needed to help make variable-rate population and N rate work. We planted four corn hybrids at three sites in Illinois over two years, using combinations of 18,000, 34,000, and 50,000 plants per acre 0, 80, 160, and 240 lb N/acre. Across three environments where shortage of water reduced yields, 50,000 plants/acre yielded less than the two lower populations, both of which yields about the same. There was lit... |
584. The Effects of 40 Years of Tillage and Fertility Practices on Soil Organic Carbon and Fungal PopulationsSoil organic carbon plays an integral role in long-term soil productivity. In cultivated systems, potential productivity is directly related to soil carbon concentrations, highlighting the need to protect current organic matter levels and develop management practices that will enhance soils with declining soil carbon contents. There have been variable responses in soil carbon levels to both tillage and fertility treatments. Tillage alters the physical and chemical properties of the soil environm... |
585. The Use of Organic Soil Amendments for Winter Wheat Production in KentuckyMost animal manures are land-applied in the fall and spring after crops have been harvested or prior to planting. Surface application of manures in the fall have more potential for nitrogen (N) loss when applied to fallow land compared to land cropped to winter wheat. This study was conducted to determine the N availability of fall applied organic fertilizers and resulting wheat grain yields compared to urea-N fertilizer. The effects of three organic fertilizer sources and rate on wheat yield an... |
586. Sulfur and Micronutrient Fertilization for Wheat Production in KansasGenetic advances in wheat (Triticum aestivum) and increased yield potential may require changes in fertilization programs including the addition of secondary and micronutrients. The objective of this study was to evaluate wheat response to sulfur and micronutrient fertilization and evaluate soil testing and tissue analysis as a diagnostic tool. Seven locations were established in 2012 and 201, all locations were established in under dryland conditions (four locations presented in this paper). Fe... |
587. Genotype Specific Management for Nitrogen Use Efficiency in Kentucky Soft Red Winter WheatThe complex interaction of genotype x environment x management (GxExM) that defines crop yield is often only explored with research on a single genotype or a select few genotypes. Improvements in crop management and understanding local adaptation to climate variability will require a broader understanding of specific genotype interactions with management systems across multiple environments. A multi-year study investigating the potential for variety specific management systems based on phenotypi... |
588. Comparison of the MRTN and Adapt-N Derived N Rates for CornNitrogen application to corn is a large determinant for high yield, and rate has important implications for economic profitability and off-field movement of nitrate-N. Nitrogen rate recommendation systems have varied over time. A popular system was yield-goal based, with grain yield multiplied by a per-bushel factor and then rate adjusted for previous crop and other N inputs. Modifications of this system are still used today in some states. Seasonal (site-year) variability in economic optimum N ... |
589. Maximizing Yield, Income, and Water QualityThose involved with Midwest production agriculture are aware that applications of nitrogen fertilizer can have unintended consequences upon water quality. It is our focus to minimize the potential of such environmental risks by working together to optimize harvest yields, and to maximize nitrogen utilization through the use of science-based initiatives, such as development of nitrogen management systems and N-WATCH. Sustainability of voluntary efforts to minimize the environmental impact of nitr... |
590. Maximizing Yield, Income, and Water QualityTo improve farm profitability and minimize environmental impact of nitrogen (N) use by reducing N losses and increasing harvest yield. Nitrogen Management System: A planned approach to N use that achieves better plant utilization and higher harvest yield with less environmental loss. It promotes a multiple application approach to N Management. It reduces early N application rates while emphasizing post-emerge N nutrition. It is about making incremental N applications that will Minimize environm... |
591. Maximizing Yield, Income, and Water QualityN-WATCH is a management tool designed for N Management Systems to inventory, track, and verify plant-available N in the soil. N Management Systems hedge the risk of N loss by splitting up the N application following the 4Rs of Nutrient Management (Right source, Right rate, Right time, and Right place). It is all about Minimizing environmental impact by Optimizing harvest yield, and Maximizing nutrient utilization. It is all about focusing on M.O.M. Who is eligible: Ag Producers that are adoptin... |
592. Maximizing Yield, Income, and Water QualityA program sponsored by the Illinois Council for Best Management Practices (CBMP) to provide local growers an estimate of the location, form, and concentration of plant- available N remaining in the soil. Plant-available N at a point in a field and a point in time can be estimated utilizing this technique and provide information that may help minimize environmental impact by improving harvest yield and maximizing nitrogen utilization. (This is not to be used as a stand-alone N recommendation syst... |
593. Maximizing Yield, Income, and Water QualityA program sponsored by the Illinois Council for Best Management Practices (CBMP) to provide local growers an estimate of the location, form, and concentration of plant-available N remaining in the soil. Plant-available N at a point in a field and a point in time can be estimated utilizing this technique and provide information that may help minimize environmental impact by improving harvest yield and maximizing nitrogen utilization. (This is not to be used as a stand-alone N recommendation syste... |
594. Minimizing Nitrate Loss from Manure-amended Wisconsin Sandy SoilsThe impact of dairy manure application on nitrate leaching was evaluated at two sites with no manure history. Manure treatment (separated-solid manure, separated-liquid manure, separated- liquid manure plus a nitrification inhibitor, and two treatments with no manure) was the main plot. Each manured plot was split into six subplots with three receiving a single sidedress fertilizer application of 0, 56, or 112 kg N ha -1 while the others had two sidedress applications totaling 112 kg N ha-1 with... |
595. Overview of Manure Handling on Steroid Movement in Agricultural Fields from Beef Cattle SystemsManure generated from concentrated animal feeding operations may serve as a source of steroids in surface water and potentially in groundwater. The objectives of this research were to determine the amount of steroids and metabolites in runoff from beef cattle production pens, and from runoff and leaching from crop production fields. Cattle were fed a synthetic progestagen, MGA or melengestrol acetate and treated with zeranol, trenbolone acetate, and estradiol implants, while a second group was n... |
596. Evaluation of Wavelength from Ground-Based Active Optical Sensors for Corn Yield Prediction in North DakotaGround-based active-optical (GBAO) crop sensors have been used successfully to predict crop yield when used during early growth stages. The objective of this study was to evaluate two GBAO sensors wavelengths regarding their usefulness under North Dakota corn (Zea mays, L.) growing conditions. Thirty experimental sites were used in North Dakota to conduct N rate trials on corn during 2011 and 2012. All sites were designed as randomized complete blocks with four replications and six nitrogen (N) ... |
597. Determining In-season Nitrogen Requirements for Maize Using Model and Sensor Based ApproachesThere is great value in determining the optimum quantity and timing of nitrogen (N) application to meet crop needs while minimizing losses. Applying a portion of the total N during the growing season allows for adjustments which can be responsive to actual field conditions which result in varying N needs. Two methods of determining in-season N needs were evaluated, a model-based approach and a crop canopy sensor approach. The Maize-N model was developed to estimate the economically optimum N fer... |
598. Soybean Response to Sulfur Placement and Starter Fertilizer ApplicationReduced rates of early season nutrient mineralization from earlier planting dates, increased nutrient removal from greater yields, and reductions in atmospheric sulfur (S) deposition have increased concern regarding S availability for optimal soybean (Glycine max L.) growth. A field study was established to determine the effects of 25 lbs. S per acre with or without starter fertilizer consisting of 20 lbs. nitrogen (N) per acre and 50 lbs. P2O5 per acre on soybean grain yield and quality. Main p... |
599. Searching for Inputs to Increase Soybean YieldCommodity prices and production costs are both at higher levels than in prior periods, encouraging growers to maximize returns by managing costs and raising yields. We conducted experiments at three Illinois sites in 2012 to evaluate foliar fertilizer, foliar insecticide, lactofen herbicide, seed treatment, foliar fungicide, foliar fungicide + foliar insecticide, cytokinin, , and fertilizer N, alone or in combinations of factors, including some deletion' treatments. Serious drought through the ... |
600. Geographic Trends in Alfalfa Stand Age and Crops that Follow AlfalfaTo gain perspective on alfalfa-annual crop rotations in the upper Midwest, USDA-National Agricultural Statistics Service cropland data layers and Soil Survey Geographic Database layers were combined for six states (North Dakota, South Dakota, Nebraska, Minnesota, Iowa, and Wisconsin) and seven years (2006-2012). Soil texture and geographic location both significantly affected the length of the alfalfa phase (stand age), and alfalfa stand age, soil texture, and year all significantly affected the... |
601. Nitrogen Management of Temporary Waterlogged Soil to Improve Corn Production and Reduce Environmental N LossDuring the 2011 growing season excessive soil moisture in the Unites States accounted for at least 30% of the total crop loss to environmental stresses resulting in more than $3 billion dollars in insurance indemnities paid to farmers. The objectives of this study were to: (i) assess grain yield and N silage uptake for both rescue and non-rescue treatments of different enhanced efficiency products, (ii) determine soil N content among treatments throughout the growing season, and (iii) evaluate P... |
602. Measuring Soil Quality Changes in Corn and Soybean RotationsSoil quality is described as the ability of the soil to sustain crop growth and development along with nutrient cycling and water infiltration and retention. One possible strategy to maintain or increase soil quality is crop rotation. Crop rotations have the potential to increase crop yields, disrupt diseaseand pest cycles, and when a legume is added to the rotation, reduce nitrogen fertilizer requirements. Although the long-term productivity and sustainability of agriculture are dependent on ma... M. Adams, G. Behke, E. Nafziger, M. Villamil |
603. Assessing the Use of Enhanced Efficiency Fertilizers on Sugarbeet Yield and QualityA field study was initiated in Frankenmuth, MI to study the effects of enhanced efficiency fertilizers in comparison to standard nitrogen (N) programs on sugarbeet (Beta vulgaris L.) yield and quality. The study was arranged as an 8 treatment randomized complete block design with four replications. All treatments received 40 pounds N/A as 28% UAN applied as a 2x2 (in) at planting with total N applications at 160 pounds N/A. Treatments consisted of urea sidedressed with light cultivation, N appli... C. Bauer, K. Steinke |
604. Can Soil Information Better Inform Canopy Sensor Algorithms for Corn?Corn production is often limited by the loss of nitrogen (N) due to leaching, volatilization and denitrification. The use of canopy sensors for making in-season N fertilizer applications has been proven effective in matching plant N requirements with periods of rapid N uptake (V7-V11), reducing the amount of N lost to these processes. However, N recommendation algorithms used in conjunction with canopy sensor measurements have not proven accurate in many fields of the U.S. Cornbelt, resulting in... , N.R. Kitchen, J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, F.G. Fernandez, E.D. Nafziger, C.J. Ransom, , J. Shanahan, G.M. Bean |
605. Better Maize Response to Optimal Fertilizer PlacementIncreasing trends in corn (Zea mays L.) yields require greater levels of applied nutrients per acre to maintain or increase yields; thus, we need to rethink how to best supply a crops⤙ required nutrients. One significant challenge associated with applying more fertilizer to support greater yields has been the negative environmental effects of increased levels of some nutrients, such as phosphorus. Fertilizer application technologies such as banding the fertilizer below the plant increases... |
606. Corn Nitrogen Evaluation in South DakotaCurrent Nitrogen (N) recommendations for corn in South Dakota use an N rate calculator approach (yield goal x 1.2 ⤓ soil test Nitrate-N (0-2 ft) ⤓ legume credits ⤓ other credits such as manure application or N in starter fertilizers + 30 lbs N/a for no-till). The N coefficient has been modified in the past from 1.45 in 1975, to 1.3 in 1982 and currently 1.2 determined 1991. The N coefficient is in dire need of re-evaluation becaus... A. Bly, S. Berg, P. Sexton, R. Gelderman |
607. Assessing the Status of Soil Phosphorus, Potassium and pH for Soybean Production in OhioSoybeans are one of the most valuable agronomic crops produced in Ohio, and in 2014, the value of Ohio⤙s soybean crop was $2.7 billion making soybean extremely important for agriculture and the economy. To achieve high soybean yields, it is essential to have the proper soil nutrient and pH levels; however, some nutrients can also have detrimental environmental effects. Phosphorus (P) can cause eutrophication of freshwater systems when high quantities enter waterways, furt... A. Brooker, L. Lindsey |
608. Comparison of Congranulated Fertilizer to Blends with S and Zn in Corn and SoybeansHigh yielding corn and soybean production systems in Missouri have renewed an interest in micronutrient management such as sulfur (S) which is essential for protein formation and zinc. (Zn) which is important for enzymes and metabolic reactions. Yield increases due to sulfur applications are more likely to occur during cool, wet springs when mineralization and crop growth are slow as a result of a decrease in atmospheric sulfur deposition. Soil tests in 2010 indicated that over 60% of the sam... M. Caldwell, K. Nelson, B. Burdick |
609. Crop Responses to Starter Fertilizer... |
610. Determining Cropping System and Topsoil Depth Effects on Phosphorus and Potassium Nutrient DynamicsUnderstanding the effects of fertilizer addition and crop removal on long-term change in soil test phosphorus (STP) and soil test potassium (STK) is crucial for maximizing the use of grower inputs on claypan soils. Due to variable topsoil depth, nutrient supply from subsoils, and crop removal across fields, accurate P and K fertilizer management can be challenging. Current Missouri fertilizer recommendations rely on a single buffering capacity for all soils throughout the state for P, and are on... |
611. Evaluation of Phosphorus and Potassium Fertilization on Corn and Soybean Yields and Soil Test Levels in OhioThe most recent fertilizer phosphorus (P) and potassium (K) recommendations for corn and soybean grown in Ohio were established in the mid-90s and research is required to verify the appropriateness of these recommendations after 20 years. In this study, corn and soybean rotations were established and maintained at three sites from 2006 to 2014 and fertilizer P and K were applied at 1) zero rates, 2) estimated nutrient removal rates and 3) twice the estimated nutrient removal rates for each rotat... |
612. Comparison of Canopy Sensing Technologies for Corn Nitrogen Management in MinnesotaVarious crop canopy sensing tools are being used to manage nitrogen, but their utility to predict N needs in Minnesota remains unclear. The objectives of this study are to compare the effectiveness of different canopy sensing technologies at predicting corn (Zea mays L.) yield at different development stages, and compare their capability to determine in season N deficiency. Six to seven N rates at 35 to 45 kg N ha -1 increments were pre-plant applied in six fields throughout Minnesota and a rate... |
613. Corn Response to Starter Phosphorus in Addition to Fertilizer Banded with Strip-tillageProducersoften question the need for starter fertilizer application in addition to deep band with strip-tillage. The objective of this study was to evaluate the effect of phosphorus (P) starter on corn (Zea mays) in addition to deep-banded application. A study was conducted at two locations, one under supplemental irrigation and one dry land, with a corn-soybean crop rotation established in the spring of 2006. Strip-tillage was completed before corn in the rotation and soybean was planted withou... |
614. Evaluation of Macronutrient Uptake and Partitioning in Winter WheatA better understanding of nutrient uptake patterns during the growing season for winter wheat (Triticum aestivum) can help to improve nutrient management decisions at the farm level. The objective of this study was to evaluate the effect of macro and micronutrient fertilization on nutrient uptake and partitioning for a Kansas wheat variety. This study was conducted during the 2014-2015 growing season at the Manhattan North Farm research station, Kansas State University. The experimental design w... |
615. Evaluation of Soybean Response to Micronutrients using Strip TrialsLimited studies are available on soybean response to micronutrients and particularly in field- scale strips. The objective of this study was to evaluate soybean tissue response to micronutrient fertilizers in fields with high soil variability. The experimental design consisted of two strips, an unfertilized and fertilized replicated three times. The treatments included an untreated control and a blend of Cu, Mn and Zn at a rate of 10 lb acre -1 and B at a rate of 2.5 lb acre-1. Soil samples were... |
616. Crop Sensors as In-season Nitrogen Management Tool for Winter Wheat in WisconsinIn Wisconsin, current winter wheat (Triticum aestivum L.) nitrogen (N) rate guidelines are determined by soil type, previous crop, and pre-plant soil nitrate test (PPNT). Nitrogen management may be improved through site-specific assessments of N need in the spring, offering a more effective use of top-dressed N. The study objective was to determine if crop reflectance measurements could be used to determine optimal in-season N rates on silt loam soils in eastern Wisconsin. This study evaluated t... |
617. Optimizing P Based In-Furrow Starter Fertilizer in Fields with Variable Soil Test P LevelsSoils in Minnesota are highly variable in chemical properties, particularly pH which can range from acidic to basic within a single field. In-furrow starter fertilizer is popular if fields with variable- and high (>7.5) pH fields to enhance early plant growth. The purpose of this study was to determine if in-furrow starter fertilizer rate should be varied in fields with varying pH and if starter fertilizer can increase yield in the presence of broadcast P applied at a non- limiting rate. Eight f... |
618. Starter Fertilizer and High Yield Management Impacts on Corn Production... |
619. Nutrient Reduction StrategiesThe Hypoxia Task Force (HTF) 2008 Action Plan set a goal or reducing the nitrogen and phosphorus load reaching the Gulf by 45% in order to reduce the size of the hypoxic zone to 5,000 km 2. Each of the 12 states along the main stem of the Mississippi and Ohio rivers were to develop a state specific strategy by 2013 to achieve the goal by 2015. These plans have been developed and work is underway to implement the strategies, but the time line was not realistic. In February 2015, the HTF announced... |
620. Micronutrients Fertilization for Corn and Soybean: A Research UpdateEssential plant nutrients such as boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), and others are absorbed by crops in very small amounts and are referred to as micronutrients. A deficiency can have a large impact on crop yield, however, because they perform important physiological functions. The soil parent material and soil formation processes over time along with effects of soil moisture, aeration, and temperature can significantly influence the amount of plant-a... |
621. Phosphorus Loss with Runoff after Applying Fertilizer or Manure as Affected by the Timing of RainfallPublic concerns about agriculture impacts on water quality and the likelihood of further government regulation have been increasing. Phosphorus usually is the nutrient that limits and controls algae growth and eutrophication in freshwater bodies. The uninformed public and many in regulatory agencies see reducing fertilization rates as an effective way of reducing nutrient loss from fields and improving water quality, especially when animal manure is applied. Soil testing for P is a useful, altho... |
622. Evaluation of Crop Canopy Sensors as a Tool for Soybean Research and ProductionDetermining the variables that consistently increase yields in soybean  [Glycine max (L.) Merr.] continues to challenge researchers, agronomists and growers alike. Crop canopy sensors have emerged as a technology used in other cropping systems to monitor and manage agricultural inputs. The sensors measure reflectance in selected wavebands that are used to calculate vegetation indices that relate to unique leaf or canopy characteristics. The objectives of this study were to determine if a comme... |
623. Are We Getting Better at Supplying Corn with Nitrogen?While the MRTN approach to making N rate guidelines is an improvement over previous methods, there remains the question about whether or not the database is sufficiently large to support the results adequately. This question is brought into focus when N rates used according to the MRTN guidelines are seen (or at least perceived) as being be inadequate in a given field or area in a given year. Other entities now making N rate recommendations may also market against the MRTN approach by raising do... |
624. Roto and Shoot Biomass and Nutrient Composition in a Winter Rye Cover CropNitrogen loss from applied fertilizer can be a significant environmental quality issue if NO 3 moves to surface or ground water. The Iowa nutrient reduction strategy science assessment identified winter cereal rye (Secale cereal L.) cover crop as a practice that can significantly reduce N and P loss (41% NO 3-N and 21% P reduction) from corn (Zea mays L.) and soybean [Glycine max. (L.) Merr.] fields. Cereal rye, when used as a cover crop, through its fibrous root system is able to explore the so... |
625. Which Corn Nitrogen Fertilization Rate Tools Preforms the Best in the Midwest?Publicly-available nitrogen (N) rate recommendation tools are utilized to help maximize yield in corn production. These tools often fail when N is over-applied and results in excess N being lost to the environment, or when N is under-applied and results in decreased yield and economic returns. Performance of a tool is often based on the specific soil and weather conditions of a growing season. Research is needed to determine which tools are the most effective at recommending economical optimal N... |
626. Nitrogen Contribution from Different Manure SourcesNitrogen fertilizer equivalencies (NFE) from manure are influenced by manure type, application method, crop selection, and environmental conditions. Much of the research to determine NFE of manure was conducted in tilled systems but many producers use no-tillage (NT) to reduce soil erosion and labor requirements. The objective of this study was to determine NFE for different manure types used in corn (Zea mays L.) cropping systems. Manures consisted of composted swine manure (CSM), poultry litte... |
627. Soybean and Corn Yield Response to Fertilizar Placement and Tillage SystemNutrient availability and, consequently, yields can be strongly influenced by tillage system and fertilizer placement. Also, different genotypes and rooting systems can affect nutrient uptake and plant growth. The objective of this study was to evaluate fertilizer placement and tillage system effects on yields in soybean and corn with different varieties/hybrids. The experiment was established in two locations in Kansas and the experimental design was a randomized complete block with a split-plo... |
628. Evaluation of Fertilizer Placement for Corn with Contrasting Rooting SystemCorn genetic improvements in recent year⤙s generated hybrids adapted for water limited conditions (drought tolerant-DT). Drought tolerant hybrids were developed with conventional breeding selection process, and therefore selected based on certain characteristics such as growth habits and root system. New transgenic DT corn hybrids are also becoming available to producers. A previous study demonstrated that corn response to starter fertilizer application can vary by hybrid (Gordon et al, 19... |
629. Corn Growth and Yield Responses to Pre-plant and In-season Nitrogen CombinationsIn-season N applications may help synchronize N availability with corn uptake but further investigation is needed to validate different combinations of pre-plant and in-season N strategies. Field experiments were initiated in 2014 to investigate corn response to N management programs involving multiple N-placements, timings, and sources applied at a single N rate at two Michigan locations. Nitrogen management programs were grouped into three strategies utilizing broadcast pre-plant incorporated ... |
630. In-season N for Corn Reduced Nitrous Oxide Emissions and Drainage Water Nitrate ConcentrationFarmers want to get the N fertilizer they apply into their crop, not lose it to air and water. This can be difficult to accomplish during wet years when N loss processes are going strong. Applying N in-season can be difficult to accomplish during wet years, but reduces the odds that N will be lost before the crop has a chance to take it up. We compared 2 N management strategies (140 lb N/acre applied pre-plant and variable-rate N applied sidedress based on canopy sensor measurements) and 3 drain... |
631. Nitrogen and Phosphorus Recalibration for Sunflower in the Northern Great PlainsSunflower producers in the northern Great Plains states of North Dakota, South Dakota, and Minnesota are presently directed to N and P recommendations that originate from research performed in the late 1960s and early 1970s. These three states alone produce more than 80% of the sunflowers in the United States on a yearly basis (USDA-NASS, 2015). The current general formulas determining N and P fertilizer rate in these top-producing states are equivalent. The N recommendation is represented here ... |
632. Field to Market: The Alliance for Sustainable AgricultureField To Market®: The Alliance for Sustainable Agriculture Field To Market® is a diverse alliance working to create opportunities across the agricultural supply chain for continuous improvements in productivity, environmental quality, and human well-being. The group provides collaborative leadership that is engaged in industry-wide dialogue, grounded in science, and open to the full range of technology choices.... |
633. Improved Nitrogen Management for the Food Industry Supply ChainA project is being led by the International Plant Nutrition Institute (IPNI) and The Fertilizer Institute (TFI), with cooperation by Fertilizers Canada (FC), to help strengthen the science underpinning the Field to Market Alliance for Sustainable Agriculture Fieldprint Calculator (FPC) and its field-scale greenhouse gas (GHG) emissions estimates. Cooperating Land Grant University nitrogen (N) management scientists and USDA NRCS and ARS nitrous oxide (N 2O) emission scientists were invited to wor... |
634. Soybean Response to Broadcast Application of Boron, Chloride, Manganese, and ZincMicronutrients are essential for plant growth but in low concentration. There has been increased pressure for farmers to apply micronutrients to soybean [Glycine max (Merr.) L.] due to a perception that deficiencies have increased. The objective of this study was to evaluate soybean yield and quality response to broadcast micronutrients. A study was conducted in Minnesota from 2013 to 2014. Treatments consisted of B (0 or 2 lb ac ï¤_1), Cl (0 or 20 lb acï¤_1), Mn (0 or 10 lb acï¤_1), and Z... |
635. Influence of Plant Growth Regulators and Nitrogen Rate on Soft Red Winter Wheat Growth and YieldExcessive spring nitrogen (N) applications on wheat (Triticum aestivum) can result in reduced stem rigidity leading to plant lodging prior to harvest. Lodged wheat may reduce grain quality due to inhibition of nutrient transport from roots to grain or decrease grain yield through the inability to thresh lodged plants. Palisade (trinexapac-ethyl [TE]) is a newly labeled plant growth regulator for wheat production in Michigan and was designed to decrease internode length and increase stem thicknes... |
636. Do Soil Nitrogen Tests Relate to Nitrogen Mineralization in First-year Corn Following Alfalfa?Corn (Zea mays L.) is the most frequent first-year crop grown following alfalfa (Medicago sativa L.) in the Upper Midwest. In the majority of cases, first-year corn does not respond to fertilizer N, but sometimes large amounts are needed to optimize yield. The pre-sidedress and Illinois soil N tests (PSNT and ISNT, respectively) are early-season tests used to predict corn yield response to fertilizer N. These tests measure specific fractions of soil N and define a critical concentration to separ... |
637. Nitrogen and Harvest Impact on Biomass Yield of Perennial Warm-season GrassesUncertainties of the supply of fossil fuels from finite resources and the negative environmental impacts of their use are the two major driving forces for the search of alternative burning fuels. Perennial warm-season grasses have drawn interest as bioenergy feedstocks due to the high yielding capacity with minimal amounts of inputs under a wide range of geography, and the capability to produce multiple environmental benefits. Nitrogen (N) fertility and harvest management are considered as crit... |
638. Residue Harvest Effect on Irrigated, No-till Corn Yield and Nitrogen ResponseImmobilization of applied N is expected when much high C:N crop residue remains in the field as is typical following corn grain harvest. Immobilization of N is expected to be less if crop residue is less. The effect of reduced immobilization on N availability may more than compensate for N removed in residue harvest. Therefore, applied N requirement for a following corn crop may be less if crop residue is reduced through harvest. Residue removal decreased the economically optimal N rate (EONR) ... |
639. Topsoil Depth Influences Switchgrass Nitrogen Managment on Claypan SoilsSwitchgrass (Panicum virgatum L.) is an attractive forage or bioenergy crop option for eroded portions of claypan landscapes where grain crop production is marginally profitable. Topsoil depth to the claypan can vary widely within fields and little information exists on the impacts of the topsoil depth on nitrogen (N) management of switchgrass. Therefore, a study was initiated in 2009 at University of Missouri South Farm located near Columbia, MO on a site known as Soil Productivity Assessment f... |
640. A Mechanistic Approach to Nitrogen Fertilizer RecommendationsIn efforts to improve Nitrogen (N) management, many new methodologies involving advanced technology such as optical sensors are being utilized. Although these new technologies have been proven to improve N management, their use in production agriculture is relatively low. The majority of farmers are still using mechanistic equations or simply pounds per bushel to determine their N rates due to low cost and ease of use. However, most of these N recommendation equations are becoming antiquated, an... |
641. 4R Phosphorus Management for Soybeans in the Northern Frontier: Rate and Placement Effects on Plant Stand, Biomass and Seed YieldVery little research has been conducted to determine the best rate, source, placement, and timing of P fertilizer for modern soybean cultivars grown in the Canadian Prairies. Preliminary results of the two years of field studies at 10 locations in Manitoba showed that typical agronomic rates of seed row P did not decrease plant stand and seed yield at any sites; nor was seed yield increased at any site, even with Olsen P concentrations as low as 3 ppm.... |
642. Planting Date, Nitrogen Rate, and Nitrogen Timing Interactions to Optimize Winter Wheat ProductionWinter wheat (Triticum aestivum L.) planting date is a large contributing factor for high yield production systems located within the central Great Lakes Basin, and nitrogen (N) rate and timing strategies offer the opportunity to improve both the production and efficiency of winter wheat when considered in combination with planting date. A field study was initiated in East Lansing, MI to determine the effects of planting date, N application timing, and total N application rate on winter wheat y... |
643. Improving Corn Yield Potential with Banded Phosphorus FertilizerHigh fertilizer costs and concerns about water quality issues have caused many Midwest corn producers to take a greater interest in improving the efficiency of phosphorus (P) fertilizer applications. The objective of this research was to determine the effects of P source, rate and placement on P use efficiency in high-yield corn production systems. The experiment was conducted in 2013 at two locations in Illinois. Two P fertilizer sources (mono-ammonium phosphate (MAP, 11-52-0) or an enhanced MA... |
644. Assessing the Benefits of Radish as a Cover CropOilseed radish (Raphanus sativus L) is a popular cover crop for no-till farmers in Wisconsin, especially among those that include winter wheat in rotation since radish can accumulate large amounts of nitrogen (N). However, previously presented research in Wisconsin has not shown a clear N credit for a subsequent corn crop. Additionally, there is a lack of information that quantifies other benefits of radish, including compaction reduction and nematode suppression. The objective of this project w... |
645. Crop Potassium Uptake and UtilizationCropping systems currently face dual challenges of maximizing yields in a sustainable approach. The importance of a balanced nutrition is critical for increasing crop production. In the past decades, comprehensive studies were performed for nitrogen (N) in corn and for phosphorus (P) in soybean. From a physiological standpoint, a synthesis-analysis on potassium (K) content, utilization, interaction with other nutrients and final impact on yield is relevant and needed for properly understanding s... |
646. Evaluating the Interaction between Chelated Fe Source and Placement on Phosphorus Availability in SoybeanIn agriculture, chelating agents are used to supplement micronutrients, such as iron (Fe). However, little research has been conducted on a field scale to evaluate chelating agent effects on phosphorus (P) uptake. The objectives of this study were to evaluate four commercially available chelated Fe sources on early soybean growth and nitrogen (N), P, and potassium (K) uptake. The study was conducted at two locations, and the experimental design was a randomized complete block with four replicati... |
647. Groundwater Quality and Nitrogen Use Efficiency in Nebraska's Central Platte River ValleyIn response to increasing levels of nitrate-N in groundwater in the Central Platte River Valley of Nebraska, intensive education and then regulatory efforts were implemented starting in the 1980s, to encourage adoption of nitrogen fertilizer and irrigation management practices which can reduce nitrate leaching to groundwater. Since 1988, there have been steady declines in average NO 3-N concentrations in groundwater in the Central Platte River Valley, resulting from adoption of recommended pract... |
648. Soybean Whole Plant, and Trifoliate Phosphorus Concentration Relationships to Yield and Phosphorus Removal RatesPlant tissue analysis is becoming a more popular tool to diagnosis nutrient deficiencies. Whole plant samples may be taken early ( corrections. Leaf samples taken just before grain fill may be used to diagnose problem spots in a field. Benton Jones Jr. et al. (1991) reports that the phosphorus (P) sufficiency range for upper most developed trifoliates is between 0.26 and 0.50 percent P. There is no published data on whole plant P sufficiency ranges from V4 to V6. Nutrient grain analysis is valua... |
649. North Dakota Corn Recommendations for Preplant and Sensor Directed Sidedress NNitrogen rates for preplant N application in North Dakota have been drastically revised. The former yield-based strategy may have served when N costs were stable and relatively low and high yields in North Dakota were rarely higher than 100 bushels per acre. Due to improved germplasm developed at North Dakota State University and other northern Land-Grant Universities with favorable adaptation to North Dakota climate and soil conditions corn has become one of the most planted crops in the state.... |
650. Evaluation of Secondary and Micronutrient for Soybean Production in KansasSecondary and micronutrients are being increasingly studied for their potential to contribute to yield increase. The objective of this study was to evaluate soybean response to secondary and micronutrient fertilizer application to maximize yields. A randomized complete block design was employed with four replications, at five locations during 2013 and five locations in 2014. Treatments consisted of micronutrient fertilizer as individual nutrient for B, Cu, Mn, S and Zn, in addition to a mix of t... |
651. Phosphorus Dynamics of Land-Applied Compost Bedded Pack Dairy Barn Product in Low and High Soil Test Phosphorus EnvironmentsCharacterizing and understanding the nutrient dynamics of land applied compost bedded pack dairy barn (CBP) products is necessary because this waste management system and its fertility use are increasingly common. An aerobic mineralization study was conducted to observe the phosphorus (P) dynamics of land-applied CBP product in low and high soil test P (STP) environments. An innovative phosphorus fractionation strategy employing UV-assisted organic P decomposition helped quantify fractions corre... |
652. Effect of Starter Fertilizer and Plant Date on Soybean Growth, Nodulation, and YieldEnvironmental conditions at the time of planting are a crucial determinant to soybean (Glycine max) yield potential. In recent years, it has become common in Ohio to begin planting earlier in the growing season, as soon as mid- or late-April in some cases. However, soil conditions are typically cooler and wetter at this time as opposed to later planting dates, and nutrient availability may be limited. When planting soybeans into cool and wet soil, the application of a starter fertilizer may be b... |
653. Improving Alfalfa Production in Wisconsin with Sulfur and Potassium FertilizerThe longevity and quality of an alfalfa stand is an essential component for Wisconsin�s dairy rotations. A study was developed to determine the effects of sulfur and potassium applications on the growth and development of alfalfa stands. The objectives of this study were to determine the effect of i) S fertilizer rate, timing and form on alfalfa yield, ii) recommended or no K fertilizer application on alfalfa yield on soils testing optimum or low for K, and iii) S and K application on soil tes... |
654. Minnesota Long-Term Phosphorus Management Trials: Phase I, The Build PeriodPhosphorus (P) fertilizer recommendations are usually made using one of two philosophies, Build and Maintain or Sufficiency. In recent years, the Sufficiency approach has been questioned because of concerns of reducing soil test levels and yield sustainability and whether it has the same yield potential as the Build and Maintain approach. Trials were initiated in 2010 at six locations across Minnesota to develop various soil test P Interpretation Classes in replicated experiments. The initial ph... |
655. Use of Nitrogen Fertilizer Sources to Enhance Tolerance and Recovery of New Corn Hybrids from Early Season Soil WaterloggingCorn (Zea mays L.) production losses due to temporarily flooded or saturated soils resulting from excessive precipitation are a persistent problem in Missouri and the Midwest Region of the United States. In 2011 alone, monetary losses for corn and soybean (Glycine max) production due to excessive flooding in the Midwest were calculated to be more than $1.6 billion. Application of different sources of nitrogen (N) fertilizer may promote increased flood tolerance and recovery in interaction with d... |
656. Changes in P Uptake and Partitioning in Soybean Cultivars Released in the Last 90 YearsHistorical changes in nutrient uptake and partitioning of soybean [Glycine max (L.) Merr.] were not studied. Field studies were conducted in 2011 and 2012 to investigate phosphorus (P) uptake changes and partitioning through the growing season in 25 maturity group (MG) II, and 26 MG III cultivars. Plant samples were taken and partitioned at V4 (four trifoliates), R2 (full bloom), R4 (full pod), R6 (full seed), and R8 (physiological maturity) growth stages. In-season samples were partitioned into... |
657. Profile Distribution of Available Potassium in Des Moines Lobe SoilsPlant potassium (K) concentrations and soil fertility evaluations to predict available K have received renewed attention during the past few years due to increasing interest in harvesting crop residues as feedstock for production of bioenergy and other bio-products [e.g., button mushroom (Agaricus Bisiporus) compost]. Interest in K crop nutrition has also increased as more producers adopt reduced or no-tillage production practices. This latter situation is not new, because the potential for K de... |
658. Phosphorus and Water Quality Issues in Lake ErieWhat are harmful algae blooms? Harmful algal blooms (HABs) are so named because they can produce toxins (or poisons) that can cause illness or irritation sometimes even death in pets, livestock, and humans. The term algae is somewhat misleading since HABs are actually cyanobacteria, which are commonly referred to as blue-green algae, and are not true algae. These organisms act like many other plant and use photosynthesis to capture sunlight but unlike most plants and algae some can fix their own... |
659. Evaluation of Adapt-N in the Corn BeltNitrogen is the plant nutrient required in the largest quantity, the most likely to be deficient, and the most impactful on corn yield as well as grower profit. Providing N to a corn crop in the right amount while minimizing loss is difficult because of complex biological and chemical reactions that result in the loss of N from the crop root zone via deep percolation to ground water, lateral flow, runoff and erosion to surface waters, and volatile losses to the atmosphere as ammonia, nitrogen g... |
660. Evaluation of Weed Management Strategies on Grain Sorghum Nitrogen Status and Grain Yield Using Optical SensorsInformation on weed management options and relation to nutrient status is very limited for grain sorghum production. The objectives of this study were: (i) determine the effects of different weed management strategies on grain sorghum yield; and (ii) evaluate the impact on nitrogen (N) status and development of the crop. This study was established at two locations in 2014 (Smith and Reno Co in Kansas). The study used a randomized complete block design with 4 replications. Two main factors evalua... |
661. Potassium Management, Soil Testing and Crop ResponseNew field research is conducted in Iowa as issues or questions arise to assure that nutrient management guidelines are up to date and to address new issues. This article briefly summarizes two major projects with potassium (K) whose results are useful to improve the efficacy of nutrient management and crop production. One project focused on correlating soil-test K methods with response of corn and soybean to fertilization and on obtaining better estimates of the concentration of K in corn and so... |
662. Nitrogen Management of Bioenergy Miscanthus on Claypan Soil LandscapesBioenergy crop Miscanthus x giganteus has been well studied for its yield in Europe and certain parts of the US Midwest but little has been done to investigate Miscanthus production in settings economically marginal for grain production. This study was conducted to determine nitrogen (N) requirements and yield potentials of M. x giganteus in degraded claypan soils. The effects of N fertilizer rates were investigated at four different locations in central Missouri on a Mexico series soil (fine, s... |
663. Sulfur Fertility for Kentucky AgricultureSulfur (S) fertility concerns are becoming more common in Kentucky due to the reduction in atmospheric deposition resulting from more stringent air quality concerns. The most likely crops where S deficiency would first occur are winter wheat and alfalfa, due to mineralization rates or high removal rates. Currently few, if any, fields in Kentucky show consistent S deficiency problems. Tissue surveys were conducted in alfalfa fields during 2013 and 2014 to assess S status in alfalfa. Twenty-one pe... |
664. Fertilizer Placement and Tillage Interaction in Corn and Soybean ProductionDifferent tillage systems can affect the availability of phosphorus (P) in the soil. The objective of this study was to evaluate the effects and interaction of fertilizer placement, tillage, and varieties/hybrids for corn and soybean. The experiment was established at two locations in Kansas in 2014. The experimental design was a factorial in a randomized complete block with four replications. Three fertilizer treatments were combined with two tillage systems and two varieties/hybrids of soybean... |
665. Switchgrass Rhizobacterial Community Structure as a Function of Cultivar and Nitrogen Fertility at Two Sites in MinnesotaBiofuel production using native perennial grasses such as switchgrass (Panicum virgatum) has potential to reduce U.S. dependence on foreign oil and curtail greenhouse gas emissions. Switchgrass can also provide significant ecosystem services, such as nutrient loss reduction and carbon sequestration. Best management practices (BMPs) for switchgrass fertility are being established on a regional basis, yet little work has been done to examine the intersection of soil fertility with soil biology in ... |
666. Field Correlation of Tissue Testing for Phosphorus and Potassium in Corn and SoybeanInterest in tissue testing as a method of guiding fertilization and detecting nutrient deficiencies in corn and soybean in the upper Midwest is increasing. Tissue testing may be a helpful diagnostic tool for assessing in-season crop nutrients deficiencies. No current yield-response based interpretations for tissue test results are available in Iowa, although previous reports based on limited data collected during the 1990s and 2000s suggested that the value of tissue testing for phosphorus (P) a... |
667. Effect of Tillage, Rotation (Maize and Soybean), and Nitrogen Rate in a Long Term Study on Solvita, Water Extract, H3A Extract ValuesA long term rainfed tillage/rotation/N rate study was established in 1985 on a mostly Coleridge silty clay loam (fine-loamy, mixed, superactive, mesic Cumulic Haplustoll). The study is a factorial of plow, disk, and no-till under continuous corn (Zea mays) and corn following soybeans (Glycine Max) with five nitrogen rates (0, 40, 80, 120, 160 kg ha -1). Soil samples were taken from all rotation/tillage combinations and three N rates in the fall of 2013 to 0.20 m (8 in). They were analyzed using ... |
668. Effects of Nitrogen Managemetn on Maize Yield and Nitrate Leachingon Irrigated Sandy SoilsIrrigated sands are some of the most productive and environmentally sensitive areas in Minnesota. Reducing nitrate leaching is critical for corn (Zea mays L.) production as ground water is a major source of drinking water in these soils. The objective of this study was to evaluate agricultural technologies that may improve nitrogen (N) management for profitable corn production and mitigate negative effects in groundwater. A randomized complete block design with four replications was established... |
669. Quantifying the Effects of Nutrient Management and Cover Crops on Soil Microbial Communities and Soybean ProductionAgricultural productivity relies upon microbial communities to cycle nutrients from soil to plant yet little information is available concerning how nutrient management and cover cropping practices influence microbial activity and crop production. Lack of consistent soybean (Glycine max L.) yield response to applied fertilizer has resulted in a need to further investigate management practices focused upon enhancing soil biological activity which in turn may feed the crop. A field study was init... |
670. Soil Mineralogy and Potassium AvailabilityIn this talk, I will try to answer four questions. The outline below gives the overall framework for the presentation. 1. What are the mineral sources of potassium? Primary minerals crystallize from the magma. Those that contain K are: Feldspars (microcline and orthoclase) Micas (biotite and muscovite) Primary minerals weather decompose by several mechanisms. Chemical bonds are destabilized by acid attack. Al ions are complexed by orga... M.L. Thompson |
671. Accuracy of Credits and Soil Indicies for Predicting Nitrogen Response in Corn Following AlfalfaCorn is the most frequent first- and second-year crop following alfalfa in the upper midwestern United States. In the majority of reported cases, there is little need for additional fertilizer N to optimize yield of first-year corn following alfalfa. For second-year corn following alfalfa, fertilizer N is needed in about one-half of cases and the economically optimum N rate (EONR) has varied greatly in responsive fields. The objective of this research was to use literature data to evaluate the ... |
672. Stand Age Affects Fertilizer Nitrogen Response in First-Year Corn Following AlfalfaThrough a symbiotic relationship with soil bacteria, alfalfa can acquire nitrogen (N) from the atmosphere, use the N for its own growth, and contribute large amounts of N to subsequent crops. To estimate this N contribution, most land-grant universities use book-value N credits based on alfalfa stand density at termination. However, a recent literature analysis indicated that alfalfa stand density is not a reliable predictor of grain yield response to fertilizer N in first-year corn. That analys... |
673. Comparison of Soil Properties under Long-Term Crop Rotation and TillageShifts in cropping systems from long-term rotations including forages to mostly annual crops has intensified tillage, but has also led to the development of conservation tillage practices such as no-till. There is a shortage of information about the interactive, long-term effects of rotation and tillage on soil quality. The objective of this study was to assess soil chemical and physical properties after 15 years of crop rotation and tillage treatments. Continuous corn (Zea mays L.) (CCC), corn... |
674. Phosphorus Sorption Behavior of Kentucky Soils with Varying Indigenous Phosphorus ContentThe risk of phosphorus (P) losses from agricultural lands through surface transport to waterways increases with increasing levels of soil P. Agricultural soils in the Inner and Outer Bluegrass of Kentucky have high indigenous P content. This study investistigates the phsophorus sorption characteristics that influence the soils potential for P loss to water bodies. Four soils from the Inner Bluegrass and four soils from the Outer Bluegrass were identified as eing agriculturally significant soils ... |
675. Cover Crops Following Corn Silage and Winter WheatCover crops are widely used in Wisconsin following corn silage or winter wheat harvest to control erosion, but effects on subsequent corn yields and their optimum N rates have not been documented. Two separate studies were conducted to: (1) determine the effect of rye as a cover or silage crop on corn yields at varying N rates and (2) determine the effect of radish on corn yields and optimum N rates. In two of three years, a reduction in corn silage yield was determined following rye silage comp... |
676. Corn Nitrogen Rate Response and Crop Yield in a Rye Cover Crop SystemWater quality impairment related to N loss from crop production fields continues to be a concern in Iowa, including meeting the USEPA nitrate-N drinking water standard and reducing N export to the Gulf of Mexico. Therefore, in-field production practices would be helpful to aid in reduction of nitrate leaching and movement to water systems. One practice identified in the science assessment for the Iowa Nutrient Reduction Strategy is use of a winter cereal rye (Secale cereal L.) cover crop, where ... |
677. Cover Crops Effects on Nutrient Cycling and Fertilizer Recommendations... |
678. Nitrogen Timing, Loss, and Replacement... |
679. Assessing Nitrogen Management and Claypan Soil Variability Effects on Switchgrass using Reflectance SensingThe topsoil depth or depth to the claypan (DTC) can be highly variable across the landscape for some Midwest soils. This makes managing crops on these soils difficult because their productivity can be highly variable. In some ar eas of the landscape there can be no topsoil and leave the claypan exposed (e.g., side-slope) while in other areas it can be buried (e.g., toe-slope) (Kitchen et al., 1999). Due to the high variability of theses soils, switchgrass (Panicum virgatum L.) is a potential pro... |
680. Biochar: Waste, or Product?Nutrient losses following summer and fall manure applications result in economic and water quality problems. We tested the potential of biochar (BC) and ammonium thiosulphate (ATS) as manure additives to retain nutrients by reduci ng nitrate pool size and runoff of N and P. To determine appropriate rates to use in field expe riments, the compounds were initially added at different rates to liquid swine manure (LSM) then the slurry mixed with soil and incubated. The selected rates, based on N tra... |
681. Relationship between Nitrogen Rate and Weed Removal Timing on Corn YieldWeeds actively compete for nitrogen in corn grain production systems. Field studies were conducted in 2009 and 2010 at the Michigan State University Crop and Soil s Research Farm in East Lansing , MI to evaluate the effect of N application rate and weed removal timing on grain yield . Treatments included four preplant incorporated rates of urea (0, 67, 134, and 202 kg N ha - 1 ) and four weed removal timings (5, 10, 15, and 20 cm) based on average weed canopy height. An additional season- long w... |
682. Slow-Release Fertilizer Effect on Groundwater Nitrogen Concentration in Sandy Soils under Potato ProductionCurrent nitrogen (N) fertilizer management practices for potato farming have led to elevated levels of N in the local groundwater. Slow-release fertilizer, specifically Environmentally Smart Nitrogen® (ESN®) polymer coated urea (PCU ) may reduce the amount of N leaching to groundwater; however no field scale studies have been performed in Wisconsin to validate these assertions. Field experiments were conducted at the Hancock Agricultural Research Station using Russet Burbank potato, planted i... |
683. Enhanced Efficiency Phosphorus Application for a Corn-Soybean RotationPhosphorus (P) is an essential plant nutrient that is taken up by plants as inorganic ions (H 2PO4- and HPO 4 -2) found in soil solution. With higher fer tilizer costs, farmers are evaluating application rates and considering enhanced effi ciency phosphorus applications or treatments. AVAIL®(Specialty Fertilizer Products, Leawood, KS), NutriLife Max® (Advanced Microbial Solutions, Pilot Point, TX), and P ₂O ₅ Max (Rosen's Inc., Fairmont, MN) are three products that are intended to enhance ... |
684. Mitigating Phosphorus Movement from Agricultural FieldsAgriculture is often cited as the primary factor for the high P loads polluting Lake Erie and Ohio�۪s watersheds, but the contributions of agriculture as a system, a combination of tillage, best management practice (BMP) and fertilizer source rather than an industry is unknown. This study supplied either commercial fertilizer or poultry litter to tilled or no-till production systems with their corresponding BMPs of incorporation and cover crops, respectively, to determine the P lost via surf... |
685. Variability of Soil Test Potassium in Space and TimePotassium soil test may be highly variable within fields. In the western part of the North Central Region, where the history of K fert ilization is marked by low rates of K fertilizer and fields where K has never been applie d, natural variability of K is governed by clay content and landscape position. In areas where K fertilization has been high, man-made variability is more common. Man-made variability may be experienced as differences in historic rates within fields merged over years of own... |
686. Nitrogen Management: Unraveling the Effect of Timing and FormImprovement of nitrogen use efficiency by co rn production would decrease the potential for nitrogen loss into the environment. A study ha s been conducted in Ames, Iowa on 16 different forms and rates of nitrogen in both a continuous corn and corn-soybean production systems. There were differences among treatments; howeve r, the most consistent treatment was the SuperU applied as a 150 lb A -1 preplant or as 50 lb A-1 preplant and 100 lb A-1 sidedress and UAN with Agrotain adde d to both the 5... |
687. Nutrient Deficiency Diagnostic Training with Field and Hydroponically Grown CropsThe Manitoba Crop Diagnostic School was initiated in 1995 and annually provides training for 350 - 400 field agronomists over a two week period in mid July. Symptons of nutrient deficiencies, other than Nitrogen (N), have proven difficult to demonstrate on the fertile high organic matter loam texturd soiles of the Carman Researh Station. The following techniques have been developed to demonstrate many of the macro and micronutient deficiencies which may occur in prairie crops.... |
688. Corn Plant Uniformity Following Shallow NH3 Placement in Precision-Guided, Pre-Plant Nitrogen ApplicationsCorn (Zea mays L.) production relies extensively on different types of N fertilizers, and anhydrous ammonia (NH 3) continues to be a dominant N s ource in much of the Corn Belt. Timing and placement of NH 3 fertilizer can affect plant-to-plant uniformity and yield of corn, and especially so when high N rates are applied and there is little time between spring pre-plant NH 3 application and planting. The effects of shallow pre-plant NH3 placement on corn plant-to- plant uniformity were investig ... |
689. Evaluation of Algorithm Thresholds for Crop Canopy Sensor-Based In-Season Nitrogen Application in CornNitrogen fertilizer is frequently the most lim iting nutrient in corn production. Typically most nitrogen is applied before plan ting. Since nitrogen can leave th e soil system fairly easily, the result can be an inefficient use of nitrogen fe rtilizer. Previous research has shown increased efficiency with no reduction in yield by applying nitrogen later in the season when the crop is actively growing, with rates regul ated spatially through the use of active crop canopy sensors. This study eva... |
690. iPhone Apps: Corn Nitrogen Fertilizer Rate Calculator and Nitrogen Fertilizer Price Comparison CalculatorAs communications technology advances, there is a need for Extension to deliver information and decision- making tools that leverage these new technologies to engage existing and new clientele groups in new wa ys. Smart technologies allow ac cess to pertinent information on-the- go and out in the field, right when it's needed. ... |
691. Building a Corn Nitrogen Rate Database for Minnesota's Irrigated Sandy SoilsA study was conducted to determine the optimum N rate to apply for corn grown on irrigated sandy soils in Minnesota. Sandy soils in Minnesota vary in the texture of the surface fron silt loam to sand. Since 2006, 11 sites had 8 to 9 N fertikizer rates applied. The optimum N rate for the sandy sites with a silt loam surface texture ranged from 168 kg N/ha to 200 kg N/ha while the sandy surfaced soils optimum N rate ranged from 250 kg Nha to 280 kg N/ha. The silt loam surface soil sites optimum N ... |
692. Identification of Reasons for High Temporal Soil-Test Potassium VariationExtensive research has focused on potassium (K) fertlization and soil K testing during several decades in the Corn Belt. IN Iowa, more t han 200 conventional or on-farm strip trials were conducted since the iddle 1990s until the early 2000s. Results of this research were used to update Iowa State University (ISU) K recommendations in 1999 and in 2002. In spite of increasd knowledge about soil-test K calibration, K fertilizer placement meethods, and needed K fertilizer rates, this research demons... |
693. Effect of Late-Applied N on Corn Dry Matter, N Content, and YieldNitrogen management of corn (Zea mays L.) may be improved by delaying N application until just prior to the rapid growth phase (approximately V6-V8). This timing is commonly referred to as 'sidedress'.� Some farmers do not sidedress because they are concerned inclement weather may delay N application beyond V8, requiring high clearance equipment to apply N and possibly reducing grain yield. However, few studies have investigated the effects of late-applied N in rain-fed production environment... |
694. Winter Annual Weeds Affect Nitrogen Availability for No-Till CornWinter annual weeds effects on nitrogen availability have not been adequately studied. The objective of this study was to determine winter annual weed s effects on nitrogen availability for rainfed no -till corn (Zea mays L.) following soybeans ( Glycine max L. Merr.). Field research was conducted in 2010-2011 at 14 sites with heavy winter annual weed pressure in eastern Kansas. A two -factor factorial arrangement in a randomized complete block design with three replications included t hree her... |
695. Tillage and Nitrogen Responses to Residue Removal in Continuous CornWith the growing interest in harvesting corn stal k residue for use as biofuel comes the need to examine how residue removal might affect yield a nd N needs of the subsequent corn crop. We are conducted an experiment over the past five years ( 2006 to 2010) at four Illinois locations (three in Mollisols and one in Alfisol) in which all, part, or none of the corn residue is removed, followed by tilled and no-till split within each residue treatment, a nd with N rates split within each residue-til... |
696. Nutrient Management Studies in Bio-Fuel Cropping SystemsResearch was conducted to determine the effect of nutrient management practices on bio-fuel crop production, and to evaluate long term effects of bio-fuel crop production on selected chemical, physical and microbiologi cal properties. Experimental plots for research on bio-fuel crops production were established in 2008 at two sites in Missouri. The experimental design was an 8x3 factorial laid out in a sp lit plot design. The main plots were eight bio-fuel cropping systems including: 1) continu... |
697. Phosphorus and Potassium Removal and Leaching from Residue in Corn and SoybeanResearch is continually being conducted to adjust and update recomm endations for phosphorus (P) and potassium (K), and to be tter understand relationships betw een nutrient application, grain yield, nutrient removal with harvest, and soil-test values. Studies in Iowa and other states of the north central region have been used to develop guidelines about P and K removal rates in corn and soybean for use together with soil testing information to manage P and K. There is very large temporal varia... |
698. Survey of the Tissue Nutrient Status of Winter Wheat in KentuckyA field survey conducted in western Kentucky (KY) was initiated to determine if University of Kentucky soil fertility recommen dations for winter wheat production was adequate. Twenty- nine fields in 15 western KY counties were iden tified by county extension agents for sampling. Soil and tissue samples were collected for anal ysis in a 150 foot by 150 foot sampling area. Approximately 100 flag leaf samp les were collected, air-dried, ground, and analyzed for N, P, K, Mg, Ca, S, B, Zn, Mn, Fe, ... |
699. Switchgrass Response to Nitrogen: Trade-offs between Quantity and QualityIn 2009 and 2010, a study was conducted at four loca tions in southwest Wisconsin to determine optimal nitrogen (N) fertilizer rates and harvest timings for switchgrass quantity and quality. The study was conducted as a randomized complete bloc k, split plot design with five main plot treatments (0, 56, 112, 168, and 224 kg ha -1 of N) and three split plot treatments (mid-fall, late- fall, and early spring harvest). Dry matter (D M) yields increased between 2009 and 2010 and were most often max... |
700. Micronutrients as Starter and Foliar Application for Corn and SoybeanCorn and soybean production under high yield environments can benefit from the combined use of starter and foliar fertilization, including macro and micronutrients. The objective of this study was to evaluate corn and soybean response to starter fertilizers in combination with foliar application of macro and micronutrients to maximize yield s. Experiments were conducted in 2010 and 2011 at two locations for corn and soybean under irrigation. Starter and foliar fertilizer treatments were applied ... |
701. Evaluation of Novel Soybean Inputs to Enhance YieldThe U.S. Average soybean yield was 43.5 bushes/acre in 2010 (www.nass.usda.gov), with reports of much higher yields in some areas. With large yield differences among years and locations, as well as some high-profile marketing and publicity campaigns promoting 'high yield' management, producers are interested in any inputs or management practices that might improve yields. High soybean prices at present and interest in finding ways to increase yield have led to emergence of a number of new produc... |
702. Irigated Soybean Response to Nitroen Applied During Early Pod FormationHigh yield soybean ( Glycine max L.) has a high rate of N uptake during grain fill with maybe 2/3 of the N derived from the atmosphere. The rema ining needs to come from the soil. Previous research has found that the probability of response to N applied at early pod development (R3) for yield trials, including 44 with mean yield >60 bu/A, we re conducted in Nebraska to determine effect on soybean yield of applying N and S to the soil at R3. With 27 lb/A N applied and >60 bu/A yield, mean yield ... |
703. Adapt-N: A Computational Tool for Precise N Management in CornCurrent approaches to estimation of optimum N fertilizer rates are based on mass balances, average expected economic return based on field experiments, soil N tests, an d crop leaf or canopy sensing. However, denitrification and leaching losses of nitrogen may occur from dynamic and complex interactions among weather, soil hydrology, crop water and N uptake, and management practices , and result in high variability in annual crop N needs in maize ( Zea mays L.) production. W eather impacts the ... |
704. Nitrogen Fertilizer Additives, Which Ones Work?Nitrogen fertilizer additives were evaluated in nine different studies. In the first study, Nutrisphere had no effect on urea hydrolysis when applied with a urea solution. In a second study, Nutrisphere had no effect on nitrification when applied with a urea solution. In a third study with urea granules, Nutrisphere had little effect on ammonia volatilization. In a fourth study with urea granules, Nutrisphere had no effect on nitrification. In a fifth study, Nutrisphere was found to be less effe... |
705. Managing Riparian Buffers to Improve Soil Structural PropertiesFifty-five percent of Kentucky's stream impairments have been attributed to agriculture. Riparian buffer management may improve buffer effectiveness and reduce agricultural contaminants impairing water quality. Three mowing regimes and one native grass establishment regime were imposed in the riparian buffer zone surrounding a tributary of Cane Run Creek in Fayette County KY. Treatment plots measured 10m x 15m, with 10 replications of each treatment. One year after treatment, root biomass, soil ... |
706. Corn Residue Harvesting Effects on Yield Response to N FertilizationProducers have many choices of diverse tillage practices for their corn (Zea mays L.) production systems. However, no-till has become an important soil management practice to help reduce water and wind erosion, as well as nutrient runoff, while conserving soil moisture for crop use. No-till systems also help farmers by saving labor and time, as well as reducing farm costs due to less equipment and fuel consumption. Nevertheless, no-till production is typically more successful and has higher crop... |
707. Validating Potassium Fertilizer Guidelines in Alfalfa-corn RotationsIn 2008 to 2010, on-farm research was conducted on 10 fields with medium soil test K (STK) to validate Minnesota K fertilizer guidelines by determining the effect of K fertilizer applications on alfalfa yield and quality in its last production year, and estimating the carryover of excess fertilizer K to first-year corn. We were surprised to find that no K fertilizer was needed to maximize alfalfa yield or overall forage feed value and quality. Luxury consumption of K occurred because as K applic... |
708. Management Zone Delineation Techniques to Aid In-Season Sensor Based Nitrogen ApplicationThe increased efficiency of nitr ogen fertilizer (N) use has been a long-term goal in reduction of nitrate contamination in the stat e of Nebraska. Preliminary rese arch has shown sensor based in- season application of nitrogen has the ability to be economic and environmentally viable. Although benefits have been published there is an opportunity for increased accuracy of N application through the integration of preprocesse d georeferenced management zones. In-season sensor based N application ... |
709. Manure Management Practices to Limit Nutrient Loss from Frozen Agricultural FieldsManure applied to crop areas can be an importa nt source of plant nutrients for crop production and may improve soil quality. Relatively small amounts of nutrients especially phosphorus (P) from manure reaching water bodies can signifi cantly increase eutrophication and impair water quality. Most recommendations indicate not to apply manure to fro zen soils because the risk of nutrient loss to surface water may be increased. Our research objective was to determine the influence of manure applica... |
710. Plant Density Consequences on Nitrogen Uptake Dynamics of Maize Plants from Vegetative to Reproductive StagesThere are few studies to date that have inte nsively examined the simultaneous effects of differences in plant crowding and fertilizer N availability for different hybrids and locations on N uptake and maize (Zea mays L.) grain yield. The main research objective was to utilize a quantitative framework to bett er understand the physiological mechanisms that govern N dynamics in maize plants at varying plant densi ties and N rates. Two field experiments involving paired near-isogenic hybrids (i.e... |
711. Slow-Release Nitrogen Fertilizers and Nitrogen Additives for Field CropsNitrogen management continues to be difficult due to transformations of nitrogen fertilizers that are possible when applied to soil and the uncertainties of weather (Cabrera et al., 2008). Nitrogen fertilizer in the form of urea is subject to ammonia volatilization through the activity of the urease enzyme found ubiquitously in soil (Kissel et al., 2008). Nitrate fertilizer is subject to leaching (Randall et al., 2008) or denitrification (Coyne, 2008) depending on the water content of the soil ... |
712. Micronutrient Nutrition for Corn and Sobyean: Emerging Issues in KentuckyIn certain Kentucky regions, corn-Zn and soybean-Mn are well known crop-micronutrient problems. In response to grower observations/c oncerns in another region, soil and leaf tissue sampling indicated that pH P, K, B, Cu and Zn nutrition problems were co-mingled. A series of corn and soybean field studies were conduc ted between 2008 and 2010 to sort out/among possible problems/solutions, relati ve to similar soils in other areas of the state. The results indicate that when P and K nutrition are... |
713. Field Evaluations of Nitrogen Ramp Calibration Strips in ManitobaNitrogen Rate Calibration Strips (NRCS) were dem onstrated in some 30 farm fields of cereals, corn and canola. Mid-season assessments of crop yield sufficiency were useful in estimating the adequacy of nitrogen (N) supply. For cereals, rela tive plant height provided a simple and quick indicator of N sufficiency. This NRCS techniqu e has been used to demonstrate the provincial N rate calculator in extension and has been adapted for P de monstrations in alfalfa. ... |
714. Drainage Management and Nitrogen LossNitrate-N loss through subsurface agricultural draina ge is of local and regional concern in the Midwest. Good drainage and nitrogen management practices have the potential to reduce nitrate- N concentrations and loss from subsurface drainage systems. The five year (2005-2009) nitrogen management study in Pocahontas County, IA suggests that while fall application of fertilizer may result in higher nitrate-N concentrations than spring application during certain period of the growing season; overa... |
715. Soil Test Phosphorus Trends in OhioAgriculture is often sited as th e primary factor for high P loads polluting Lake Erie and Ohio's watersheds, but its exact contribu tion is actually unknown. This proj ect evaluated historical soil phosphorus (P) trends in the state of Ohio by collecting historical soil data from the three largest commercial laboratories servicing Ohio to dete rmine if P levels at a county resolution are changing over time. This helps address to what extent widespread over-applications of P (either commercial ... |
716. Response to Starter Applied Sulfur in Combination with Nitrogen and Phosphorus Across a LandscapeCorn ( Zea Mays L.) response to starter fe rtilizer combinations containing sulfur were studied using a replicated strip trial methodology. Combinations of ni trogen (20 lbs N), phosphorus (20 lbs P 2O5), and sulfur (25 lbs S) were applied two inches beside and below the seed with the planter and compared with a no-starter control a nd 25 lbs broadcast sulfur. Early plant growth was consistently increased by starter P and so metimes by starter N, while sulfur uptake was increased by S and P app... |
717. What Do You Do When Your N-Rich Reference Fails?In recent years, canopy reflectance sensing has b een investigated for in-season assessment of crop N health and fertilization. Typically, the procedure followed co mpares the crop in an area known to be non-limiting in N (the N-rich area) to the crop in a target area, which may be inadequately fertilized. Measurements from the two areas are used to calculate a relative reflectance to represent the potential need for add itional N fertilizer. Establishing N rich areas or strips is often inconve... |
718. Carbon Sequestration: The Lack of Initial Measurement Could Bias Interpretation of Management Effect on Soil CarbonMuch research has been done in the last decades to determine the effect of management practices on the rate of soil carbon (C) seque stration over time. Generally paired fields are sampled and soil organic carbon (SOC) content under each manage ment system is determined. Conclusions about the effectiveness of different management systems in sequestering soil C are established based on the SOC difference and le ngth of the experiment. However, properly archived historic samples are often unavail... |
719. Winter Annual Weeds Effect on Corn Response to NitrogenThe timing to control winter annua l weeds is a management concern for producers. In regards to corn response to nitrogen, the objective was to determine how important the timing of winter annual weed control is for no-till, rainfed co rn production following soybeans by assessing: soil water and nitrate; early growth and nitrogen uptake of corn; nitr ogen status of corn at silking- blister; and grain yield. Field research was conduc ted in 2010 at seven locations in Kansas. There were four diff... |
720. Active Crop Canopy SensorsActive crop sensor usage for managing crop nitrogen inputs has been an area of intense research over the last decade. The question on the minds of producers, consultants, and policymakers is how well does the technology functi on in the field? And is it robust enough for commercial usage? The goal of this proceedings article and subsequent presentation and panel discussion is to provide a little background on current approaches, research successes and failures, and commercial prospects and chal... |
721. Nitrous Oxide Emissions in Claypan Soils Due to Fertilizer Source and Tillage/Fertilizer PlacementNitrogen fertilization for agricu ltural production is a major contri butor to increased soil nitrous oxide emissions. These emissi ons may contribute to global warming and ozone depletion. Nitrogen fertilizer source and placeme nt can influence soil nitrous oxide (N 2O) emissions by affecting the concentration of ammonium and nitrat e available for nitrification and denitrification throughout the growing season. The objectives of this research were to quantify the effect of tillage / fertilize... |
722. Sensing Soybean Canopy Development Responses to and K Nutritional StressNormalized difference vegetative index (NDVI) has been correlated with physiological plant parameters and used to evaluate plant growt h. Recently, active canopy reflectance sensors have been used to determine N nutrition al needs of corn, wheat and forage grasses. There is little information about the use of this technique to detect soybean nutrient deficiencies. The objective of this work was to determine th e ability of the NDVI sensor to detect P and K deficiencies, and grain yield reductio... |
723. Changes in Soil Test Phosphorus as a Function of Inorganic and Organic Phosphorus in Animal ManureUnderstanding how and why soil test phosphorus (P) levels increase with manure and fertilizer application is important to assist in improvi ng any nutrient management plan. An incubation study investigated the change in soil test P (STP) after 42 different animal manures (dairy, beef, swine, chicken, turkey, goat, sheep, and horse) or fer tilizer were applied at a rate of 40 mg total P kg -1 to 25 different agriculturally important soils of Wisconsin. Both liquid and solid dairy and swine manure... |
724. Nitrogen Fertilization Requirement and Corn-Soybean Productivity in a Rye Cover Cropping SystemNitrogen (N) fertilizer inputs for intensive corn-based cropping systems can increase nitrate (NO 3 -N) concentrations in groundwater. Nitrogen tr ansport in surface water to the Gulf of Mexico is also an on-going issu e for the upper Mississippi river ba sin, especially areas with large corn and soybean acreage. Education and policy efforts have focused on i\provement in N application rate, timing, management, and crop N us e efficiency. However, additional means to reduce N loss are needed. R... |
725. A Smorgasbord of Preliminary Results from Field Trials in OntarioField scale trials may be established to support lo cal needs, but the results seldom reach a wider audience. This paper summarizes two recent fiel d studies by staff of the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) on fertilizer use in soybeans and corn. A study of starter fertilizer response in soybeans found that yield responses to fertilizer tended to be relatively small, and seldom large enough to cove r the cost of the added fertilizer. A second study of ammonia vola... |
726. Utilizing Fertilizer Technologies to Reduce Nitrate Leaching in the Central Sands Region of WisconsinLeaching of nitrate into the groundwater has been a continuing and extensively researched problem in the sandy soils of Wisconsin. However, no proven solution to this problem has been identified as yet. Research results from our studies in 2009 showed that several products had potential in reducing nitrate-nitrogen (NO 3-N) leaching. Although not always statistically significant, one slow-release fertilizer, Environmentally Smart Nitrogen (ESN), produced greater yields than conventional fertiliz... |
727. Quantifying Corn Nitrogen Deficiency and Application Rate with Active Canopy SensorsPrecision agriculture technologies are an integral part of many crop production operations. However, implementation for N application has lagged, primarily due to lack of a viable system for variable N rate decisions. Ac tive canopy sensors have been developed as a tool to determine plant N stress deficiency and provide an on-the- go decision for implementing variable rate. Two general approaches could be implemented. On e is to plan on conducting canopy sensing each year, with a reduced N rate ... |
728. Active-Crop Sensor Calibration Using the Virtual-Reference ConceptCalibration of laboratory and field instruments usually involves collecting data from some type of accepted standard materials or compounds. This approach works well for most physical and chemical measurements; however, such procedur es become problematic when dealing with biological systems like plants that go throug h a number of physiological states during the growing season. In addition, genetic composition differences between cultivars can affect the architecture of plant canopies a nd rela... |
729. A Seed Company Perspective on Use of Crop Canopy Sensors for Making Corn Nitrogen Fertilizer RecommendationsCurrent nitrogen (N) management practices for corn production typically include significant quantities (e.g., 200 to 250 lbs/A) of pre-plant applied N at field-uniform rates. These conventional practices can sometim es result in sizeable N fertilizer losses, especially in extremely wet springs in the Corn Belt. The lo st N not only reduces grower profits through lost fertilizer and reduced yields in N deficien t areas, but can also lead to environmental contamination through nitrate leaching or... |
730. Time of Harvest Alters Nutrient Management of SwitchgrassSwitchgrass is one of many cellulosic crops bei ng considered as a biomass feedstock for the production of bioenergy, including ethanol. It is being promoted as a crop that can grow well on marginal lands with low nutrient inputs as well as on more fertile soils. Nutrient removal is important for long-term perennial crop production. A study, establishe d to evaluate the effects of nitrogen rate and harvest management system, was used to evaluate the nutrient removal in switchgrass harvested at ... |
731. Agronomic and Nutrient Cycling Responses in a Rotation StudyA twelve-year rotation study was established in the Divide soil near Brookings SD in 2000. Treatments of crop rotations (corn-soybean, s oybean-spring wheat, and corn-soybean-spring wheat), tillage (conservation till vs. no-till), and residue management (post-harvest residue removed vs. residue returned) were established. Grain yield, residue crop residue production, nutrient cycling, and carbon storage responses were documented. Mean grain yield for various crops was not significantly influenc... |
732. One-Time Tillage of No-Till Crop Land: Five Years Post-TillageField research was conducted at two eastern Nebr aska locations to test the hypotheses that one- time tillage of no till (NT) land results in increased grain yield, reduced stratification of available soil phosphorus but reduced wet aggregate stabili ty, and increased soil organic carbon (SOC), without a long term effect on the soil microbial community. Research was conducted in long- term NT fields under rainfed corn [ Zea mays (L.)] or sorghum [Sorghum bicolor (L.) Moench.] rotated with soybea... |
733. Response of Corn to Residue Management and Nitrogen FertilizationInterest in the production of cellulosic fuel production for bioenergy has identified corn (Zea mays L.) as a suitable option. However, residue removal can affect the growth and yield of a following corn crop and its response to N fertilizer. Residue removal may also influence the optimal tillage system with regard to yield and N-use efficiency. In southern Minnesota, concern about yield reductions due to cool, wet soil conditions, partially attributed to high amounts of crop residue, have limit... |
734. Soybean foliar manganese recommendations on chronically Mn deficient soils.Soil Mn availability decreases with increasing pH and organic matter concentrations, leading to seasonal Mn deficiency symptoms in soybeans pr oduced on these soils. In Michigan, high pH conditions are often found in alluvial calcareous lakebed soils where conditions lead to low Mn solubility. High organic matter co ncentrations in organic soils reduce Mn availability due to formation of unavailable chelated Mn 2+ compounds and organic complexes in the soil. While Mn deficiencies on lakebed soil... |
735. Recommendation Development Under 4R Nutrient StewardshipThe 4R Nutrient Stewardship concept defines the right source, rate, timing and placement of plant nutrients as those leadi ng to the economic, social and e nvironmental benefits desired by stakeholders. This implies roles for both science and stakeholder engagement . Scientific data on the linkages to outcomes needs to be communicat ed to stakeholders to ensure their valid participation and to build public confidence. Th e 4R Nutrient Stewardship concept helps to link science to practice and co... |
736. Soybean Growth Components as Influenced by No-till and Strip-till Systems and Different P and K Rates and PlacementsReduced tillage and broadcast phosphorus (P) a nd potassium (K) applications can lead to accumulation of these nutrients in the soil surfa ce. The objective of this study was to determine the impact of conservation tillage (no-till and strip-till) and rate/placement of P and K on soybean production. The experiment was arranged in a split-split-block design with three replications with tillage/placem ent no-till broadcast (NTBC), no-till deep placement at 15 cm (NTDP), and strip-till deep placeme... |
737. Evaluation of Nitrate Leaching Potential from Slow and Controlled Release Nitrogen Fertilizer Application to Irrigated CornThe use of slow and controlled release nitrogen (N) fertilizers as a practice to reduce nitrate leaching from irrigated corn was evaluated on coar se-textured soils in the Central Platte River Valley of Nebraska in 2007 & 2008. Slow-releas e methylene urea (MU) and polymer-coated urea (PCU) were compared to a standard fertil izer of urea ammonium nitrate (UAN) solution. Flooding in 2007 severely impacted the study site, and results are not reported here. Saturated soils were common at the site i... |
738. Current Perceptions on Soil Fertility Recommendations and Status of Soil Fertility in IllinoisWhile most soils in Illinois are generally recognized for their high productivity, regular application of phosphorus (P), pot assium (K), and limestone are necessary to maintain their productivity. Determination of soil P, K, and pH levels through soil analysis is necessary to guide application of these nutrients and limestone. Due to recent high fertilizer prices there has been interest from producers to temporarily reduce or eliminate P and K applications without reducing crop yield. In an ef... |
739. Nitrogen Recalibration for Spring Wheat and Durum in North DakotaNorth Dakota will begin using new fertilizer r ecommendations beginning Dec. 1, 2009. Previous recommendations required a yield guess by growers with no rega rd to economics of nitrogen application. The new recommendations recogni ze different N response curves with yield and grain protein within three state agri-climatology zones. The reco mmendations use the "return to N" method, which vary the N recommendation based on crop price and N costs. The resulting rate is adjusted based ... D. Franzen, G. Endres, J. Lukach, R. Ashley, J. Staricka, K. Mckay |
740. Micronutrients in Northern ClimatesEarly work on micronutrients in northern US dates back to the late thirties and early forties and dealt primarily with boron (B) (Cook 1939; Cook a nd Millar 1940; Pierre and Allaway 1941). In Manitoba, it was initiated in the sixties and id entified zinc (Zn), copper (Cu) and manganese (Mn) as potential problem micronutrients. Early work also id entified organic (peat) soils as a primary target for micronutrient deficiencies. Work on mineral soils would produce significant yield responses in th... |
741. A Nitrogen Rate of Return Calculator for Wheat, Barley, and Canola in ManitobaNitrogen (N) general guidelines in Manitoba ar e reviewed by a panel of government, industry and university experts on an annu al basis and revisions as well as additions and corrections are reflected in the Soil Fertility Guide that is published (as well as posted on the web-site) by Manitoba Agriculture, Food and Rural Initiatives. However, a comprehensive review of the N databases for barley, wheat and canola has not been undertaken since September 1990. Post 1988 database of experiments cond... |
742. What are the Benefits of Canopy Sensing for Variable-Rate Nitrogen Corn Fertilization?Canopy reflectance sensing for assessing crop N health has been proposed as a technology on which to base top-dress variable-rate N applicat ion. The objective of this research in Missouri was to evaluate the economic a nd environmental benefit of activ e-light crop-canopy reflectance sensors for corn N rate decisions. A total of 16 field-scale experiments were conducted over four seasons (2004-2007) in three major soil areas. Mu ltiple blocks of randomized N rate response plots traversed the le... |
743. 2009 - The Summer of Plant Analysis: What Did We Learn?There was a significant increase in the number of samples submitted for plant analysis to the UW Soil and Plant Analysis Laborat ory during the 2009 growing seas on. The objective of this study was to analyze the data from plant samples submitted to the UW Soil and Plant Analysis Laboratory over the past five years to determine if any relevant plant nutrition trends appear. ... |
744. Long Term Phosphorus Studies and How they Effect RecommendationPhiosophiesProfitable crop production requires adequate levels of phosphorus (P) and other nutrients. Careful planning is required because of volatile grain and fertilizer prices and increasing public concerns about water quality impa irment due to excess nutrient loss from fields. Higher fertilizer prices may not be a major issue as long as the hist orical ratio between crop and fertilizer prices is approximately maintained, becomes more favora ble, or increases can be predicted. Largely unpredictable pri... |
745. The Changes in Soil Test Potassium in Kentucky Soils Following Incubation and the Addition of Potassium FertilizerSoil test potassium levels across the state of Kentucky have been declini ng for the past several years. The high price of potash fertilizer has definitely played a role in this decrease, but crop removal rates have also been increasing. This re search is being conducted to improve fertilizer recommendations, to help producers raise or ma intain K soil test level, and to obtain an optimum, profitable yield. Curr ently, University of Kentucky has a single set of K recommendations regardless of so... |
746. Using Optical Sensors to Make N Recommendations for Sorghum, Wheat and Corn in KansasEfforts were begun in 2005 focused on developi ng sensor based N recommendations for grain sorghum ( Sorghum bicolor L. Moench), winter wheat ( Triticum aestivum L) and corn (Zea mays L.). The objective of these studies was to develop sensor based mid-season N recommendations using active crop sensors currently available on the commercial market. Sensors used to date include the GreenSeeker and CropCircle. Our appr oach used has been to establish multiple in- field well fertilized reference str... |
747. Soil pH and Lime Management for Corn and Soybean: An Ongoing On-farm ProjectSoil acidity can affect plant growth directly and indirectly by affecting the plant-availability of nutrients, levels of phytotoxic el ements, microbial activity, and ot her soil properties. Soils may become acidic in the long term as a result of several natural processes. In the short term, however, soil acidity develops mainly due to application of N fertilizers or manure, primarily those having high concentrations of ammonium or urea because nitrification releases hydrogen (H) ions. Soil pH ... |
748. Early Season Nutrient Uptake from Combinations of N itrogen, Phosphorus, and Potassium Applies in Starter Fertilizer in Two Corn HybridsConventional small plot field trials were establ ished to study the effect nitrogen (N), phosphorus (P), and potassium (K) applied as starter ferti lizer on early season growth and nutrient uptake of two corn hybrids with a nd without the Bt-rootworm gene. Ei ght locations were studied over two years comparing a non-starter check, N only, K only, NP, NPK, and NK starter fertilizer combinations on early season growth and nutrient uptake. Sites tested High initially in both P and K. One or more st... |
749. Fertilizer ManufacturingRock Phosphate + Sulfuric acidPhosphoric Acid + Gypsum Phosphoric Acid + Anhydrous Ammonia MAP or DAP (18-46-0) Phosphoric Acid + Rock Phosphate TSP (46-0-0) Concentrated Phosphoric Acid + Anhydrous Ammoni a APP (11-37-0) 1. Ore containing KCl and NaCl is mined, brought to the surface and ground up 2. Reagents added in a brine to remove clays 3. Reagents added to attach to KCl crystals 4. KCl crystals floated to the surface in flotation cells 5. NaCl separated to tailings pile or put back under... |
750. Potassium in Corn Starter Fertilizers RevisitedDespite the importance of potassium in crop nutriti on, there has been relatively little assessment of potassium in starter fertilizer s, and particularly where sufficie nt preplant broadcast K has been applied to meet the needs of the crop. Initial re sults from the first year of a multi-year study in Southern Ontario showed that corn yields were increased by about 0.4 t ha -1 by the inclusion of potassium in a starter fertilizer on low P and K testing soils, above the response to added P. Fur... |
751. Dealing with Sulfur Deficincies in Crop Production: The Iowa ExperienceResearch conducted for more than forty years (pri or to approximately 2005) in Iowa rarely noted improved crop yield with sulfur (S) fertilization. Studies during that time period with corn and soybean found yield increase from S fertilizer application only three times out of approximately 200 trials. Research in the early 1980's had also documented sufficient plant available S in the soil profile for crop production on most Iowa soil associations. Results of recent studies (2000- 2005) in corn ... |
752. Corn Nitrogen Rate Response Trials in Northwest and Westcentral Minnesota, 2007=-2009With the growing number of corn producers and increased acres of corn in NW and WC Minnesota along with the revisions in the Univer sity of Minnesota Corn Nitrogen Guidelines (2006) many northern corn growers were asking a bout the validity of the new nitrogen guidelines for corn production in the region. Prior to 2007, University of Minnesota calibration and correlation data included in the new guidelines did not include any research sites north of Interstate 94. A request for funding from the ... |
753. Foliar Fertilizer and Pyracolstrobin Fungicide Combinations for CornIncorporating a foliar applied fert ilizer with fungicide application could reduce application costs, improve disease suppression, increase nutrient re sponse, and enhance the management of crop response to environmental conditions within th e growing season. A two-year field trial was initiated in 2008 at three sites in northeast, southeast and northwest Mi ssouri. Treatments consisted of a factorial arrangement of 13 diffe rent commercially-available foliar fertilizers containing both macro- a... |
754. Integration of Ultrasonic and Active Canopy Sensors to Estimate the In-Season Nitrogen Content for CornThe objectives of this research were to: (i ) determine the correlation between active canopy sensor (ACS) assessments of N status and ultr asonic sensor measurements of canopy height at several growth stages for corn receiving varying am ounts of N, (ii) test the ability of both sensors to distinguish N-mediated differences in canopy development and (iii) test the integrated use of both sensors. This experiment was conducted with varying N rates in an existing long-term study and farmer's field... |
755. Effects of Sampling Time, Soil Moisture Content, and Extractant on Soil Test Potassium LevelsAn accurate prediction of plant-available pota ssium (K) requires a thorough understanding of the mechanisms that might impact soil test K. A three year field study was developed to determine relationships between soil test potassium (STK) levels and time of soil sampling, soil moisture content, and extractant. Five field sites were established in 2006 throughout Wisconsin at Arlington, Hancock, Marshfield, and Lancaster Agricultural Resear ch Stations, and a private farm in Fond du Lac county ... |
756. Use of Nitrogen Mangaement Products and Practices to Enhance Yield and Nitrogen Use Efficiency in No-till CornLong- term research has shown that nitrogen (N) fertilizer is usually needed to optimize corn production in Kansas. Research has also shown differences in the response to various N fertilizers, products, and practices , particularly in the eastern portion of the state, where soil and climatic conditions regularly can lead to N loss. A project was initiated in 2008 and continued in 2009 to quantify how a number of currently marketed products and commonly utilized management practices performed at... |
757. Effect of Phosphate and Sulfate Application on Wheat (Triticum Aestivum) Grain Selenium Content and Yield ComponentsThe interest in Selenium (Se) has increased due to its potential anti-cancer attributes in human health. Wheat ( Triticum aestivum ) will assimilate Se according to soil availability. There is interest in developing a consiste nt grain supply of high Se wheat for markets in Europe and Asia since plant-available Se in soils of these continents are very low. Agricultural soils in some regions of central and western South Dakota ha ve high Se content. Yet the common plant available forms of Se, sel... |
758. Effects of Glyphosate Application and Manganese Fertiization on Leaf Manganese Concentration and Yield of Glyphosate-Resistant SoybeanGlyphosate-resistant (GR) soybean is widely accep ted in the United States. Recent research in Indiana and elsewhere has observe d that post-emergence foliar applications of glyphosate may cause or exacerbate manganese (Mn) deficiency and then limit yield of GR soybeans on low Mn availability soils. The objectives of this study were to 1) better understand how glyphosate application(s) might reduce the up take and translocation of Mn in GR soybean plants, and 2) determine the effectiveness of s... |
759. Alternative Approaches to Making Fertilizer RecommendationsThe objective of this research project was to evaluate, both agronomically and economically. some common altcrnative methods of making fertilizer recornmcndations for corn, soybeans, and soft-red winter wheat used in Indiana. Over a period of six years ( 1992- 1997) the effect of seven alternative fertilizer recommendation philosophies on soil test levels, crop yields, plant tissue analysis, and fertilizer additions were measured in an attempt to determine differences in performance between thes... |
760. Basic Concepts of Soil Acidity and LimingMost midwestern soils require periodic applications of aglitne or other liming materials for optimum crop production. Liming has several beneficial effects: I ) it reduces harmhl or potentially tosic conditions which can develop in acid soils; 2) it increases the availability of some of nutrients: 3) it replaces the supply of calcium and magnesium essential for plant growth which is depleted as soils become acid; 4) it ensures favorable conditions for the activity of certain herbicides; and 5) i... |
761. Chloride Fertilization on Wheat, Corn, and Grain SorghumResearch in the Pacific Northwest and the Northern Great Plains has documented positive cereal grain responses to chloride (CI) fertilization. Field research was conducted in Kansas evaluating CI fertilization on winter wheat, corn, and grain sorghum. Chloride fertilization consistently and significantly increased plant CI concentrations in all crops. Chloride fertilization increased grain yields or one or more winter wheat cultivars at 3 of 4 sites. The most dramatic yield increases were at th... |
762. Deep Banding Phosphorus and Potassium for No-till Corn and SoybeanThe information presented is part of ongoing research to identify effective fertilizer placement methods and diagnostic tools lor phosphorus (P) and potassium (K) in no-till corn and soybeans. There is uncertainty about soil test interpretations and cost-effective methods of fertilizer application for the no-till systcni. Moreover, producers are uncertain about the value of soil testing in conservation tillage because of large variability and lack of knowledge concerning techniques for collectio... |
763. Effect of Nutrient Combinations and Nitrapyrin in Starters on CornExperiments were conducted from 1994 to 1996 at the Belleville Research Center of Southern Illinois Univerity and the Dixon Springs Agricultural Center of the University of Illinois to evaluate the effect of starter fertilizers. nitrapyrin (N-Serve) amendment of the starters, and tillage on conn. The soil at the Belleville site was an Iva silt loam, a low organic matter soil with relatively high P and K soil test levels. At Dixon Springs a Bonnie silt loam (bottomland) soil was used and the soil... |
764. Hypoxia in the Northern Gulf of Mexico- Causes and ConsequencesSeasonally severe and persistent hypoxia, or low dissolved oxygen concentrations, occur on the inner to mid-Louisiana continental shelf to the west of the Mississippi River and Atchafalaya River deltas. The areal extent during mid-summer surveys of 1993- 1997 ranged from 15.800 to 18,200 km2. The shelfwide distribution in mid-summer for 1985 to 1992 averaged 8,000 to 9,000 km2. Hypoxia occurs below the pycnocline from as early as late February through early October, but is most widespread, persi... |
765. Influence of Nitrapyrin on Nitrate Concentrations in SoilsIn central Ohio most of the water used for d&g comes from the Scioto River Watershed. This water shed in primarily composed of farmland in which corn and soybeans are the dominant crops. Periodically the nitrogen in the Scioto River exceeds safe drinlung water standards of 10 ppm nitrate nitrogen. Several EPA studies have concluded the high nitrate nitrogen levels are the results of nitrate flushes through the underground tile in agricultural fields. These flushes of high nitrates usually from l... |
766. Intensive Nitrogen Management of Soft Red Winter WheatThe current system of making nitrogen recommendations for wheat in the Eastern cornbelt assumes that nitrogen fertilizer required is a simple function of yield potential. The higher the yield potential, the more N fertilizer needed. The problem with this assumption is that factors such as soil type and ability of a site to release N through mineralization, climate, variety. disease pressure and managetnent practices all affect nitrogen use efficiency, and are not considered in making nitrogen re... |
767. Interaction of Soil Applied Herbicides with Soil pHManagement of soil pH is important in enhancing the availability of certain plant nutrients and in minimizing toxic levels of other elements to crops. However, the reaction of herbicides with soils under varying soil pH levels can affect both crop growth and herbicide performance. Soil pH affects herbicide performance in several ways. When crops are under stress due to nutrient imbalance from unfavorable soil pH levels, application of certain herbicides may increase risk of crop injury. When soi... |
768. Limestone Sources and Factors Affecting Their QualityAddition of liming materials to correction soil acidity is an age old practice. According to Barber (1984). Cato and Varro used lime to correct soil acidity about 200 B.C. In America. benefits derived from liming acid soils were docuniei~ted in the early 1800's (Ruffin, 1821). In a sunfey conducted in 1980. all but two of the North Central States (North Dakota and South Dakota) reported that research had shown a need !'or limc (Whitney, 1980). The need has not changed over the last 17 years, i.e... |
769. Liming in No-till SystemsIn 1985 a study was initiated at Penn State to look at the effects of surface application of lime on a very acid, long-term no-till soil. Since 1977 this field had been in no-till corn production with no limestone applied. The initial pH of "plow layer" was 5.1 and the surface 2 inch pH was 4.5. The limestone recommendation, based on the SMP buffer pH and a target pH of 6.5, was 6000 Ib calcium carbonate equivalent (CCE) per acre. The study included four limestone rates (0. 3000, 6000.9000 Ib CC... |
770. Methods and Limitations of Zone Sampling Using Topography as a Logical BasisTwo forty-acre fields in North Dakota were sampled in a 110 foot grid. Each field was measured for elevation in the same 110 foot grid. Topographic sampling zones were identified in each field and a correlation of the sampling based on these zones was compared to the correlation values from a 220 foot grid. Nitrate-N and the 220 foot grid were both correlated to the 110 foot sampling values for nitrate-N and P. A map of field nitrate-N levels from topography sampling compared to the 220 foot gr... |
771. Nitrogen Availability to Corn Following Small GrainsNitrogen rate recommendations for corn are generally reduced following legumes compared to following corn or small grains. A 4-yr field study was conducted on a Plano silt loam soil in southern Wisconsin to evaluate the capability of soil NO3 tests to predict N availability to corn follo~b-ing small grains. Previous crop small grains included \vinter wheat, winter qe. and oats harvested for grain and straw. Nitrogen fertilizer was applied to corn at rates of 0 to 180 Ib/a in 30 Ib increments. Gr... |
772. Nitrogen in the Mississippi River Basin- Sources and Factors Affecting Loss of Nitrate to the RiverNitrogen (N) is a naturally occurring element that is essential to plant growth and crop production. In a soil system, nitrate-N is continually supplied through mineralization of soil organic matter. Other sources of N include fertilizers, animal manures, municipal sewage wastes, agricultural and industrial wastes, atmospheric deposition. and dinitrogen fixation, all of which either occur as nitrate-N or can be converted to nitrate-N through mineralization and nitrification. ... |
773. Performance of Early vs. Late Maturing Corn Hybrids in MichiganThe planting of fill-season, or late maturing hybrids in Michigan is encouraged by their tendency to produce higher yields. Full-season hybrids can take advantage of the entire growing season available at a particular location. Shorter season hybrids reach physiological maturity sooner and generally yield less. Recent experience with cool, wet springs resulting in delayed planting, and growing seasons that provided less growing degree days (GDD) than normal has caused corn producers to question ... |
774. Precision Phosphorus Management for SoybeanSoybean responds to phosphorus fertilization in the Midwest. Most correlation and calibration data suggests that soybean is less responsive than corn. Because of this. normal management in the Upper Midwest is to fertilize before the corn crop in a corn-soybean rotation for both the corn crop and following soybean crops. This saves the cost of one application and the logistical problem of fertilization with P after a corn harvest. This management works well in soils tvith a pH less than 7.4 and... |
775. Predicting N Fertilizer Rates for CornSixteen N rate experiments were carried out in farmer fields in 1995 and 1996. The objective was to measure optimum N fertilizer rates and see whether they could be reliably predicted ahead of time. Yield response to N was measured in each experiment along with soil N measurements (planting and sidedress), and tissue N and chlorophyll meter reading at sidedress time. A very wide range of economically optimum N fertilizer rates was found, fairly evenly spread from 0 to 200 Ib N/acre, with an aver... |
776. Remote Sensing as a Tool for AgricultureThe tendency for nearlv everything in our society to be bigger, better, faster, easier, cheaper, and safer than in the past has resulted in many challenges. Agriculture is not immune from these trends, and in some cases agriculture even leads the way. Incorporation of remote sensing into site- specific management activities is one area where technologies are being merged to develop a new array of products that are intended to help producers and consultants make better and more timely management ... |
777. Response of Minimum-till Corn to Starter Fertilizer and ACAStarter fertilizer containing N and P often increases grain yield under no-till management. but yield responses to starter have riot been consistently observed under conventional tillage. Experiments were established in 1996 and 1997 at six sites varying in latitude, soil type. fertility, and crop rotation to evaluate the effect of starter fertilizers on corn grown under high-residue minimum-till systems. In one experiment, a factorial combination of 3 N. 2 P, and 2 K rates placed in a 2x2 band ... |
778. Spoke Injection of Fertilizer Phosphorus for GrassesFertilization of forge grasses with phosphorus has shown limited forage increases in South Dakota, even with low soil tests. Lack of response to added phosphorus may partially be due to fertilizer placement on established grass stands. Traditionally broadcasting fertilizer has been the only placement method available. Since P moves very iiiile in the soil, root feeding from tne added P must occur very ciose to the soil surface. A dry soil surface could limit P uptake by grasses, limiting any yie... |
779. Topsoil Thickness Influence on Phosphorus and Potassium Availability and Crop ResponseSoil testing to estimate nutrient availability and fertilizer needs is a widespread management practice for cropping systems in the United States. as well as in other countries. The purpose of soil testing is to simulate the ability of the plant roots lo uptake these various nutrients critical for normal growth. Crops generally uptake a s~nall amount of phosphorus (P) compared to potassium (K). The portion of soil P that is readily available for plant growth maybe limiting due to the small quant... |
780. Using Soil Properties to Predict Soluable Phosphorus Losses from Indiana SoilsEscessive phosphorus (P) levels in surface water can degrade water quality by causing algal blooms and accelerating the eutrophication process. Agriculture has bceri implicated as a major nonpoint source of P, so many states have considered restricting P applications from inorganic fertilizers, manures, and other Pcontaining materials once soil test P levels esceed "threshold values". Relationships between soil properties and soluble P loss potential have not been welldocumcnted. This laboratory... |
781. Variable Fertilizer Nitrogen Application Based on the Delta Yield Index- A Field StudyA quick review of the both the scientific and popular literature indicates that many different approaches have been suggested for the prediction of variable fertilizer N applications in the field. In previous meetings of this conference we have presented the general outline and approach taken for our site-specific crop management project in Ontario. Briefly, historical data sets of grain corn response trials to fertilizer N (encompassing some 300 site-years worth of data) indicated that most yi... |
782. Field Estimation of Ammonia Volatilization from Surface-applied UreaAccurate estimation of the potenial for NH3 volatilization from urea-based fertilizers is an important step in optimizing Nuse efficiency from these fertilizers. Published estimates of volatilization from surface-applied urea vary widely. Citations listing losses from 2% on up to 80% from various systems can be found. Consequently, many growers, to protect themselves, will apply urea at higher than recommended rates, assuming some arbitrary level of loss will occur. The objectives of the researc... |
783. Impact of Phosphorus and Potassium Fertilization on Corn and Soybean Productivity and Soil Nutrient LevelsA common production practice in the Eastern Corn Belt is to supply enough phosphorus (P) and potassium (K) in the fall prior to corn planting to satisfy the nutrient needs of both corn and soybeans in a rotation. This practice is most likely a viavle option for fields with more than adequate soil nutrient levels, but on marginal fields this practice may be limiting production (specifically with regard to K). Two field experiements were estabished to evauate the impact of P and K fertilization... K.A. Dietrick, R.W. Mullen, C.E. Dygert |
784. Re-Evaluating Rate, Time, and Placement of Urea and Other Nitrogen Sources in MinnesotaUrea is increasingly an important nitrogen (N) source in Minnesota. Approximately 43% of our farmers use urea as their major N source. In the southwestern, south-central and west-central areas approximately 45% of the N is applied in the fall, 50% is applied in the spring, and 5% is applied at sidedress. While most of those that use urea as the major N source apply it in the spring, approximately 4% do the major application with urea in the fall and there are others that apply some of their N... F. Fernandez, K. Fabrizzi, J. Vetsch, D. Kaiser |
785. How Agronomic Management Affects Soil Nitrous Oxide EmissionsThe effects of crop and soil management practices on soil emissions of non-carbon dioxide (CO2) greenhouse gases (GHGs) such as nitrous oxide (N2O) are highly variable, and long-term field data are limited. Management strategies that impact nitrogen (N) mineralization are also likely to affect how N is lost to the atmosphere as N2O gas. This presentation covers the agroecosystem soil N cycling concepts leading to losses as N2O as well as... V.L. Jin, M.R. Schmer, B.J. Wienhold |
786. A 2020 Vision on Nutrient Use DecisionsMany farmers this fall are facing significant financial stress due to several factors including low crop prices and weather-induced crop losses. Crop prices are currently much lower than they were in the first half of this decade but we have been here before … time tested principles continue to apply. Past studies of the characteristics of the most profitable farmers show that they tend to have higher yields, lower costs, and are more rapid adopters of technology than their less profit... P.E. Fixen |
787. No-till and Cover Crops Influence Soil Health and Nitrogen Rate and Timing Recommendations: Early ResultsThe idea of improving soil health has become increasingly more talked about by researchers, agronomists, and farmers in the past five years. Management practices such as no- or reduced-tillage and planting cover crops are recommended to improve soil health because of their potential to improve organic matter and soil structure leading to a greater capacity to hold water and nutrients needed for plant growth. Research in South Dakota has been occurring these past two years to determine the inf... J.D. Clark, A. Bly, D. Karki, D. Sanyal, J. Wolthuizen, P. Kovacs |
788. Impact of sulfur and its interaction with N rates on wheat and barley in North Dakota and Western MinnesotaEffects of S, N, and their interactions were assessed on grain yields and protein of spring wheat and barley, across eight site years in Western Minnesota (MN), and ten site years (hereafter, sites) in North Dakota (ND) from 2015 to 2019. The studies were to determine if S improves yields and protein in wheat, and if the effects were dependent on N rates. Treatments included all combinations of five N rates of N (0, 60, 120, 180, and 240 lbs/ac) and three rates of S (0, 10, 20 lbs/ac) in MN. ... J.M. Teboh, S. Yuja, B.G. Schatz, G. Pradhan |
789. Efficacy of Variable-Rate Application Technology for Phosphorus, Potassium, and Lime ManagementVariable-rate (VR) application technology may improve P and K fertilizer and lime use efficiency, increase crop yield and the profitability of crop production, and reduce within-field soil-test variability. On-farm research assessed the potential of VR P or K fertilization and liming for corn and soybean in Iowa. Replicated strip-trials evaluated one to three cycles of the two-year rotation. Treatments for areas 10-30 acres in size were a non-fertilized or unlimed control, VR based on dense g... A.P. Mallarino |
790. Evaluating Relationships between Soil Respiration and Nitrogen Use Efficiency in CornAvailable nitrogen (N) often limits the agricultural production of corn (Zea mays) and the N fertilizer use efficiency is of primary concern for producers in Kansas and the Midwest. This study was carried out to understand the agronomic value of commercially available soil health tests (e.g. 24 hr CO2 burst) and their relationship to components of nitrogen use efficiency (NUE) in corn. Relationships between N response and soil CO2 evolution were investigated across multiple sites and manageme... D. Ruiz diaz, B. Rutter |
791. Nitrogen Non-Cycling from Cover Crops Grown Before Corn and Spring Wheat-Unexpected Early Project ResultsNitrogen credits in North Dakota State University fertilization recommendations include those anticipated from the previous year annual legume crops (field pea, lentil, soybean, chickpea) and from terminated alfalfa. In addition, it was established in the region that sugarbeet tops returned to the soil may have an N credit potential of up to 80 pounds of N per acre (Crohain and Rixhon, 1967; Moraghan and Smith, 1994a; Moraghan and Smith, 1995a; Moraghan and Smith, 1995b; Franzen et ... D. Franzen, A. Wick, H. Bu, L. Ressler, J. Bell, M. Berti, C. Gasch |
792. Correlation of the Weak Organic Acids Test of a Soil Health Tool with Crop Yield Response to Phosphorus FertilizationThe field correlation of a soil P test with yield response to P fertilization is the foundation for sound soil-test interpretations and fertilizer recommendation guidelines. Weak organic acid extractants have been used to measure soil P for decades in some northeastern states of the US and other countries, but not in Iowa or the Midwest. A new test based on a mixture of malic, oxalic, and citric acids (H3A) was developed as a component of a Soil Health Tool to measure soil P and K. The H... A. Mallarino, J. Jones |
793. Does it Pay to Sidedress Some of the Nitrogen on Corn?Dividing the amount of nitrogen fertilizer applied to corn over two or three applications has become a common practice, based on the understanding that waiting to apply some of the N lowers the potential for loss of N, and that applying N during vegetative growth stages enables N to get into the plant quickly when the plant is rapidly taking up N. Across 20 sites, spring preplant ammonia at 200 lb. N/acre, fall-applied ammonia at 100 lb. N/acre + 50 lb. N as UAN injected at planting + 50... E. Nafziger |
794. Manure, Phosphorus, and 125 Site-Years of Edge-of-Field Runoff MeasurementsPhosphorus export from agricultural fields continues to create water quality concerns in Wisconsin. The UW Discovery Farms program, along with Discovery Farms Minnesota have collected 125 site-years of edge-of-field monitoring datawhich can be used to better understand the relative effects of inherent soil properties (slope, drainage class, texture), management practices (manure application, tillage, crop rotation, cover cropping), and soil test P values on seasonal (frozen and non-... M. Ruark, A. Thompson, Z. Zopp, T. Radatz, A. Radatz, E. Cooley |
795. Corn Nitrogen Management Following Cover Crops and the Microbial ResponseCover crops (CCs) may provide tools for fertilizer management and opportunities to influence soil biological communities. However, corn (Zea mays L.) growth and microbial response remain unclear when corn nitrogen (N) management strategies are practiced in combination with specific CCs. Field studies were conducted in 2015 and 2016 to evaluate the effects of no CC, Daikon radish [Raphanus sativus (L). var. The Buster], and Forage oat [Avena sativa (L.) var. Magnu... K. Steinke, J. Rutan |
796. The Economics of Corn and Soybeans... R. Batts, G. Schnitkey |
797. Nitrification Inhibitor Value in Irrigated Corn: Insights From a Long-term StudyProper nitrogen (N) nutrition is key to optimizing corn yields. Due to its dynamic behavior in soils, N can be lost through different pathways and negatively impact corn production. Nitrification inhibitors (NI) decrease the rate of ammonium transformation to nitrate in the soil, potentially decreasing denitrification and leaching potential. However, NI only has a positive effect on yield if environmental conditions are conducive to loss to the point of N becoming limiting to crop p... L. Bastos |
798. Active-Optical Reflectance Sensing Evaluated for Red and Red-Edge Waveband SensitivityUncertainty exists with corn (Zea mays L.) N management due to year-to-year variation in crop N need, soil N supply, and N loss from leaching, volatilization, and denitrification. Active-optical reflectance sensing (AORS) has proven effective in some fields for generating N fertilizer recommendations that improve N use efficiency. However, various sensors utilize different wavebands of light to calculate N fertilizer recommendations making it difficult to know which waveband is most sens... G. Bean, N. Kitchen, J. Camberato, R. Ferguson, F. Fernandez, D. Franzen, C. Laboski, E. Nafziger, J. Sawyer, P. Scharf, J. Schepers, J. Shanahan |
799. Manure and Fertilizer Management Influence on Soil Nutrient Levels and Grain Yields in Eastern South Dakota from 2003 to 2014Concentrated animal feeding operations (CAFOs) are required to hold a manure management permit in South Dakota. The permit encompasses available nutrients from manure, crop nutrient use and removal, soil test nitrate-N, and phosphorus and land availability for approved nutrient application rates. The management plan determines if nitrogen or phosphorus based manure application rates are used. Most CAFO’s start out following the nitrogen based plan as soil test phosphorus (P) levels... A. Bly, S. Berg, R. Gelderman, B. Rops, P. Sexton, C. Morris |
800. Relating Soil Properties to Spatial Variation of Phosphorus Critical LevelVariable rate (VR) fertilizer application has increased with proliferation of VR capable equipment. Current recommendations for VR phosphorus (P) application often assume that critical level is constant across a field adjusting only for spatial variation of soil P concentration. We conducted this study to determine whether variation in critical level, identified by relative yield of unfertilized to fertilized plots, could be explained by soil properties. In 2016, plots, me... J. Bowen |
801. Fertilizer management and cover crop effects on phosphorus use efficiency, environmental efficiency and crop yieldPhosphorus loss from agricultural production is a significant contributor to the degradation and contamination of surface and ground waters. To help protect these waters, it is vital to maximize agronomic and environmental efficiency of phosphorus in the cropping system. The objective of this study was to quantify the effects of cover crops and different phosphorus fertilizer management practices on nutrient use efficiency, environmental efficiency and yield in a no-tillage corn-soybean rotat... R. Carver, N. Nelson, G. Kluitenberg, K. Roozeboom, P. Tomlinson |
802. The Importance of Soil Health and the Efforts of NRCSSince its inception in 1932, USDA-NRCS has worked with agricultural producers and landowners to address natural resource concerns, and improve long-term productivity on the nation’s private working lands. The mission of the agency is accomplished primarily through local field staff who provide technical assistance, and work with interested farmers and ranchers to develop conservation plans that improve identified resource concerns. In addition to site-specific technical&n... D. Chessman |
803. Do Split-Nitrogen Applications in the Midwest Affect Corn Nitrogen Uptake and Grain Yield?It is hypothesized that split-nitrogen (N) relative to single near-planting applications improve corn (Zea mays L.) grain yield and nitrogen recovery efficiency, which can lessen environmental impacts of fertilization. However, these hypotheses have not been fully tested. A 49-site-year study across eight US Midwestern states over three years was conducted to compare near-planting (Single) and split-N (Split) applications. Three N application timings were evaluated [Single near plan... J. Clark, F. Fernandez, J. Camberato, P. Carter, R. Ferguson, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, J. Sawyer, J. Shanahan |
804. Integrating Management Zones and Canopy Sensing for Improved Nitrogen Recommendation AlgorithmsActive crop canopy sensors have been studied as a tool to direct spatially variable nitrogen (N) fertilizer applications in maize, with the goal of increasing the synchrony between N supply and crop demand and thus improving N use efficiency (NUE). However, N recommendation algorithms have often proven inaccurate in certain subfield regions due to local spatial variability. Modifying these algorithms by integrating soil-based management zones (MZ) may improve their accurac... J. Crowther, J. Parrish, R. Ferguson, J. Luck, K. Glewen, T. Shaver, D. Krull, L. Thompson, N. Mueller, B. Krienke, T. Mieno, T. Ingram |
805. Soil Organic Matter as it Relates to Soil Health and Plant NutritionTotal organic matter via loss on ignition is a standardized soil measurement in the North Central region. There is wide spread consensus that total organic matter is a very important indicator of the fertility of a soil, but how many farmers actually use total organic matter values from a soil test in an actionable way? An alternative approach would be to focus on the active fraction of organic matter. This is a small, but important pool that reflects the biologically available and ... S. Culman |
806. Arbuscular Mycorrhizal Fungi and Their Role in Modern AgricultureArbuscular mycorrhizal (AM) fungi are obligate symbionts of over 90% of land plants, including most of the worlds economically important food crops. This symbiosis is believed to have evolved some 400 million years ago concurrentwith land plant flora to assist in phosphate uptake, an ion of poor mobility in soil. A key feature of the symbiosis is the ‘arbuscule’, a fungal organ that penetrates root cortical cells and forms a convoluted peri-arbuscular membrane of large surfac... R. Drijber |
807. Recalibration of Potassium Requirements for Corn in North DakotaThe previous North Dakota potassium recommendations for corn were borrowed from central Corn Belt states, where the dry soil-based 1 M ammonium acetate extraction for soil test K was utilized with a critical K value of 150 ppm. This value was adequate before 2000 because corn production was limited to only a few counties in southeastern North Dakota, and soil test K values were commonly above 300 ppm. However, the intensification of corn production in these counties and an increasing acreage ... D. Franzen, J. Breker, M. Rakkar, A. Chatterjee |
808. Crop P Nutrition and the Three Pillars of Soil Health: Less Soil Disturbance, Greater Crop Diversity, Organic Nutrient SourcesThe soil health initiative is built around a number of principles, but three central components are reduced soil disturbance, especially no-tillage; increased crop diversity, especially cover crops; and greater use of organic materials (manures, composts, etc.) as nutrient sources. Reduced tillage intensity causes temperate soil environment changes such that oxidation of organic matter is slowed and phosphorus (P) stratification is reinforced. Cover crop insertion heightens P cycling, ge... J. Grove |
809. Cover Crops and Tillage Interaction on Claypan Soils of Southern IllinoisIncreased nutrient leaching due to agricultural practices such as tillage and fertilization is a significant environmental concern. Nitrogen (N) mineralization stimulated by tillage can increase the risk for nitrate leaching before subsequent crops have an opportunity to take up the N released by microbial activity. An alternative measure for reducing potential nutrient loss via leaching and runoff is use of cover crops (CCs). A field experiment was conducted at the Southern Il... S. Gurbir, J. Schoonover, K. Williard, K. Gauge |
810. Cereal Rye and Hairy Vetch Cover Crops for Improving Soil and Water QualitySoil and water quality benefits of cover crops (CCs) have been inferred only from plot scale studies. Replicating cover crops at the watershed scale and expecting similar results to that of plot scale studies need further research. Therefore, cover crop study at Southern Illinois was carried at the plot as well as the watershed scale. The objectives of plot scale study were (i) to evaluate the contribution of fertilizer and soil organic matter (SOM) to N leaching under corn/soybean ... S. Gurbir, K. Williard, J. Schoonover, R. Cook, R. Mcelroy |
811. Root Growth and Phosphorus Uptake Affected by Fertilizer Management in Soybean and WheatPlant root growth patterns can be affected by nutrient and water availability. The objective of this study was to assess the effect of phosphorus (P) fertilizer management on soybean (Glycine max. L) and winter wheat (Triticum aestivum L.) root system growth and macro and micronutrients uptake. Two greenhouse studies were carried out at Kansas State University, Manhattan, Kansas under controlled environment. The experimental design... F. Hansel, D. Diaz |
812. Nitrogen and Potassium Interactions in CornExtensive research in the North Central region has investigated separately nitrogen (N) and potassium (K) fertilizer management for corn. However, there is scarce information available about how N and K interactions affect corn grain yield and nutrient uptake. The objective of this study was to evaluate the effects of various combinations of N and K rates on corn yield, N and K tissue concentrations, and N and K removed with grain harvest. Two trials with continuous corn were conducted from 2... J. Hirniak, A. Mallarino |
813. Minnesota Long-Term Phosphorus Management Trials-Phase II: Sufficiency Level vs. Build and Maintain ApproachesCurrent Minnesota P recommendations for corn and soybean are based on the Sufficiency approach. In recent years, it has been questionable that the Sufficiency approach could maximize potential grain yield in today’s agricultural systems. The objective of this research was to establish six long-term experiments across Minnesota to test phosphorus management strategies on soils with a defined long-term phosphorus history. Four soil test P (STP) Interpretation Classes&n... D. Kaiser |
814. Influence of phosphorus management on potential for soluble phosphorus loss through leachingThe over application of phosphorus (P) fertilizers in agricultural systems may pose a threat to water quality due to the loss of dissolved P to fresh water bodies leading to eutrophication. The objectives of this study were to evaluate the potential for water soluble P loss from top soil (0-6 inches) across a range of initial soil test phosphorus (STP) levels, soil types, and leaching volumes; and to determine if P leaching loss could be predicted with existing soil P tests. Intact soil colum... L. Leverich, D. Kaiser |
815. Evaluation of Agricultural Lime and Pelleted Lime to Increase Soil pH and Crop YieldAgricultural lime (aglime) is applied to increase pH of acidic soils to values optimum for crop production, and its effectiveness is affected mainly by it calcium carbonate (CaCO3) equivalent (CCE) and fineness. Availability and use of pelletized limestone has increased in recent years, but there is limited information about its effectiveness. Six field trials were established in 2014 at acidic Iowa soils (pH 4.9-6.1) with contrasting texture and organic matter. Treatments replicated three ti... A. Mallarino, M. Haq |
816. Basic Concepts of Soil Acidity and LimingWith today’s cropping systems utilizing high rates of N fertilizers, most Midwestern soils require periodic applications of aglime or other liming materials for optimum crop production. Liming has several beneficial effects: 1) it reducesaluminum or manganese toxicity, harmful or potentially toxic conditions which can develop in acid soils; 2) it increases the availability of some of the essential nutrients; 3) it replaces the supply of calcium and magnesium essential for plant gro... D. Mengel |
817. Comparison of Ground-Based Active Crop Canopy Sensor and Aerial Passive Crop Canopy Sensor for In-Season Nitrogen ManagementCrop canopy sensors represent one tool available to help calculate a reactive in-season nitrogen (N) application rate in corn. When utilizing such systems, corn growers must decide between using active versus passive crop canopy sensors. The objectives of this study was to 1) determine the correlation between N management by remote sensing using a passive sensor and N management using proximal sensing with an active sensors. Treatments were arranged as field length strips in a randomized comp... J. Parrish, R. Ferguson, J. Luck, K. Glewen, L. Thompson, B. Krienke, N. Mueller, T. Ingram, D. Krull, J. Crowther, T. Shaver, T. Mieno |
818. Soybean Seeding Rate and Nutrient Interactions on Growth and Yield in MichiganSoybean (Glycine max L. Merr.) prices are forecast to remain stagnant placing greater emphasis on production costs for growers across Michigan. Seeding rates and fertility inputs are two factors producers can manage to influence economic return. Field research was conducted in Richville and Lansing, MI in 2017 to evaluate biomass production and yield in response to nutrient inputs and help determine economically optimal seeding rates. The study was desig... T. Purucker, K. Steinke |
819. Targeting Input Responses and Returns on Intensively-Managed Soft Red Winter WheatConsecutive years of record wheat (Triticum aestivum L.) yield (81 and 89 in 2015 and 2016, respectively), climate variability, and continued demand from Michigan’s milling and cereal industry have increased interest in intensively-managed (i.e. multiple-input) soft red winter wheat production systems. The objective of this study was to investigate the grain yield and economic profitability of several agronomic inputs across intensive (i.e., multiple- input) and traditiona... D. Quinn, K. Steinke |
820. Late-Split Nitrogen Application On CornThe practice of applying a last (or additional) increment of N fertilizer during late vegetative growth of corn using high-clearance equipment has grown rapidly in the last few years, despite the absence of evidence supporting the profitability of this practice. We established a set of trials in which a range of N rates from 0 to 280 kg/ ha were applied as UAN solution, either all at planting or with 56 kg N reserved and hand-applied at the base of the plants at tasseling (late-spli... D. Rapp, E. Nafziger |
821. The Effect of Agricultural Management Practices on Labile Soil Carbon and Nitrogen in WisconsinAmid ever-increasing enthusiasm for soil health there remains uncertainty about how best to measure it, to interpret the results, and to adapt agricultural management accordingly. One factor of particular interest to farmers is the capacity of a soil to mineralize organic matter, making nutrients available to crops. This research takes a survey-based approach to identify how labile carbon (C) and nitrogen (N) – as permanganate oxidizable carbon (POxC), potentially mineralizable carbon (... G. Richardson, M. Ruark, E. Silva, M. Chawner, E. Olson, A. Radatz, C. Zegler |
822. Can a Winter Rye Cover Crop Mitigate Nitrate Leaching from Corn Production on Irrigated Coarse Textured Soils?Minnesota has approximately 500,000 acres of irrigated coarse textured soils. These soils are very productive but are highly vulnerable to nitrate (NO --N) leaching and ground water contamination. In these soils, most of the NO --N leaching losses take place in early spring and late fall, when precipitation is high and crops have limited water and nutrient uptake. The objectives of this study are 1) quantify the capacity of rye (Secale cereal L.) as a cover crop to mi... N. Ricks, F. Fernandez, J. Baker |
823. An Integrated Approach to Understanding Poultry Litter Use in Corn-Soybean Production SystemsThe majority of poultry litter (PL) in Kentucky is generated in the western third of the state, the same area that produces approximately 80% of corn, soybean, and wheat. This PL is applied to row crop fields as a nutrient source. Producers and commodity board representatives were concerned with reported nutrient availability coefficients, nutrient value, and long-term use of PL. Four field sites in a NT corn-soybean rotation were identified in the fall of 2012 with low to medium soil test va... E. Ritchey, E. Haramoto, C. Bradley |
824. Corn grain nitrogen and yield with foliar nitrogen application at early reproductive growth stageLate fungicide applications in corn with the use of high clearance equipment create the opportunity for additional foliar fertilizer applications. The objectives of this study were to (1) evaluate the benefit of fungicide applications on yield and grain N in combination with foliar N applications and (3) assess the value of foliar N the application using N sources with urea- formaldehyde/triazone during the VT-R1 growth stage. This experiment was conducted at 6 locations in 2016 and 2017... A. Stammer, D. Ruiz diaz |
825. The Science Behind NutrientStarNutrientStar is a science-based assessment and education program that is focused on products and tools that are marketed to increase nitrogen use efficiency. The program was initiated about three years ago by the Environmental Defense Fund with a primary focus on corn production in the Mississippi River Basin. NutrientStar operates with support from a panel of ten soil scientists plus administrative consultant staff. Panel activities include developing recommended protocol... J. Schepers |
826. Stover Removal Effects on Continuous Corn Yield and Nitrogen Use Efficiency Under IrrigationCorn (Zea mays L.) residue or stover is harvested as supplemental feed for livestock and is a primary feedstock for cellulosic biofuels. Limited information is available on corn residue removal effects on grain yield under different nitrogen (N) fertilizer rates, irrigation rates and amelioration practices to minimize soil carbon loss and soil erosion. A study on a silt loam in south, central Nebraska (2011-2016) evaluated potential interactions between stover removal (residue r... M. Schmer, V. Jin, A. Sindelar, R. Ferguson, B. Wienhold |
827. Should Corn Nitrogen Fertilizer Guidelines be Adjusted for Late N Fertilizer Applications?Late application of nitrogen (N) fertilizer is a topic that is receiving considerable attention. Previous research in Kansas has shown that split applications of N fertilizer can increase yield compared to applications at planting in some site years. This study was designed to investigate how N rate recommendation guidelines can be affected by splitting N fertilizer application with applications during late vegetative growth stage. Four corn study locations were established in North Central a... A. Stemmer, D. Ruiz diaz |
828. Nitrogen Fertilizer For SoybeanConcern about soybean’s ability to provide energy to fix adequate N while still producing high yields has led to renewed interest in in-season use of N fertilizer. We conducted a series of fertilizer N timing experiments in Illinois, in different soil types with a range of yield potential. There were few responses to N in silt loam soils, with unfertilized check yields ranging from 4,108 to 6,125 kg/ha, though applying the same N increment four times increased yield sig... J. Vonk, E. Nafziger |
829. Post-Harvest Soil Nitrate Following Corn Production in Eight Midwestern StatesApplying nitrogen (N) at economically optimal rates (EONR) and at times of rapid crop uptake are practices that are thought to minimize the amount of residual soil nitrate (RSN) in the profile that may be susceptible to loss. The objective of this study was to evaluate the effects of rate (0 to 280 lb N/a in 40 lb increments) and timing (pre-plant (PP) or PP plus V9 sidedress (PP+SD)) of N application on corn grain yield and RSN in the top 3 feet of soil relative to the calculated EONR. Thirt... C. Bandura, C. Laboski, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, E. Nafziger, J. Sawyer, J. Shanahan |
830. Can Unmanned Aerial System-Mounted Passive Sensors Be Used To Recommend Sidedress Nitrogen Rates In Corn? A Comparison Between Active and Passive SensorsThe objectives of this research were to (i) assess the correlation between active and passive crop canopy sensors’ vegetation indices at different corn growth stages, (ii) assess sidedress variable rate nitrogen (N) recommendation accuracy of active and passive sensors compared to the agronomic optimum N rate (AONR) and (iii) assess sidedress VR N rate recommendation correlation between active and passive sensors. Two experiments were conducted, one near Central City, Nebraska on a Novi... L. Bastos, R. Ferguson |
831. Tillage, Crop Rotation, and Cover Crop Impact on Corn Nitrogen Requirements in Southeastern South DakotaNitrogen is the lifeline of corn production. There is uncertainty whether nitrogen (N) requirements are the same for corn raised under long term no-till versus conventional till production systems. The objective of this study was to evaluate N fertilizer requirements for long term no-till soils in southeastern South Dakota, while considering effects from cover crops and crop rotation. This was a two year study at the SDSU Southeast Research Farm near Beresford, SD on long term no-till plots e... S. Berg, P. Sexton, R. Gelderman, A. Bly, C. Derdall |
832. Managing Urea Fertilizer for Optimal N Use and Productivity of CornCorn (Zea mays L.) yield is usually limited by nitrogen (N) availability more than any other nutrient in agricultural soils. Urea is the primary source of inorganic nitrogen fertilizer used worldwide, either as a crystalline solid containing 46% N, or a urea-ammonium nitrate solution (UAN, 28-32%). A major caveat, however, to urea as an N fertilizer is its susceptibility to loss through volatilization when applied to the soil surface. Many products are marketed as nitrogen stabi... B. Bernhard, F. Below |
833. Do Soil Tests Predict Yield Response to Phosphorus in Modern Corn and Soybean Production?Modern corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] production systems produce higher yields, and consequently, may remove more nutrients than fertilizer rates based upon existing soil test recommendations for these yields. With greater emphasis on soil test levels for nutrient stewardship strategies, soil tests need to also predict critical levels in which fertilized nutrient responses are likely. Current soil test recommendations for Illinois have negl... T. Beyrer, F. Below |
834. Corn Nitrogen Calibration in South DakotaSouth Dakota (SD) corn nitrogen (N) rate recommendations were last established in 1991 and based on the coefficient of 1.2 lbs N/bu of the yield goal. The South Dakota corn N rate calculator subtracts the pre-plant soil test NO3-N (0-2ft) and legume credits and adds 30 lbs N/a for recently established no-till. Much improved corn genetics, shifting farming practices, and climate changes warrant re-calibration of corn N rate recommendations. During 2013-2105, N rate studies were conducted at 20... A. Bly, S. Berg |
835. Potassium Recalibration for Corn in North Dakota and Sampling TimePotassium (K) fertilizer recommendations for corn (Zea mays, L.) are commonly guided by yield response calibrations to soil K levels; however, sample drying and time of soil sampling have been shown to affect the amount of extractable K. Potassium rate trials were established at 13 locations in southeastern North Dakota during 2015 with objectives to evaluate soil K testing methods and their relationship with corn yield response to K fertilization and to assess temporal soil K variat... J. Breker, D. Franzen |
836. Manitoba Corn Meets 4-R Nitrogen Management (Year 2): Effects on Crop Performance and the EnvironmentReplicated corn trials to evaluate previous research on fertilizer technologies were conducted in 2015 under farm conditions at three sites Manitoba as well as in Quebec. Sites were located northwest of Elm Creek, MB on a loamy fine sand, near Carman, MB on a loamy very fine sand and at Culross, MB (southeast of Elm Creek) on a Red River clay. Treatments in the Manitoba trials included: a zero N Check; three rates of urea/ESN (50% each by weight) broadcast/incorporated prior to plan... C. Cavers, S. Sager, G. Parent |
837. The Anaerobic Potentially Mineralizable Nitrogen Test as a Tool for Nitrogen Management in the MidwestThe anaerobic potentially mineralizable nitrogen (PMNan) test is a tool that can improve estimations of mineralizable nitrogen (N) and enhance nitrogen use efficiency. This tool may also help improve predictions of N uptake, grain yield, and the economic optimum nitrogen rate (EONR) of corn (Zea mays L.). A 32 site-year study across eight US Midwestern states was conducted to 1) compare the effect of incubation length (7-, 14-, 28-d), soil sampling timing, N fertilizer rate, and thei... J. Clark, K. Sloan veum, F. Fernandez, J. Camberato, P. Carter, R. Ferguson, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, J. Sawyer, J. Shanahan |
838. Topsoil Thickness Effects on Phosphorus and Potassium Dynamics on Claypan SoilsDue to variable depth to claypan (DTC) across landscapes, nutrient supply from subsoils, and crop removal, precise P and K fertilizer management on claypan soil fields can be difficult. Therefore, a study was performed to determine if DTC derived from soil apparent electrical conductivity (ECa) could be used to improve P and K management for corn (Zea mays L.) and soybean (Glycine max [L.]). Research was conducted on a claypan soil at the University of Missouri&rsq... L. Conway, M. Yost, N. Kitchen, N. Kitchen, K. Sudduth |
839. Potassium Effects on Yield, Grain Quality, Lodging, and Stalk Strength in RiceMissouri has a long history of rice production, going back to 1910 when the crop was first grown in the northeast region of the state. From this 40-acre start, rice acreage has increased steadily over the years to over 180,000 acres currently. The statewide average yield was 110 bu/A in 1997 and increased to over 156 bu/A in 2015. Traditionally, nitrogen (N) management has been given top priority by farmers. But with increased yields and rotations with soybeans, K fertility is increasingly be... D. Dunn, G. Stevens |
840. Phosphorus Distribution After Long-Term P Fertilizer Placement Under Strip-TillageLong-term phosphorus fertilizer placement under strip-tillage tillage can affect the vertical and horizontal distribution of soil test P (STP). The objective of this study was to evaluate the effect of P fertilizer placement on STP distribution under strip-till. A study was established in Scandia, Kansas in 2006 under a corn- soybean rotation. Treatments included a (1) control (No P); and P applied at 80 lb P2O5 ac-1 as (2) broadcast, (3) deep band, (4) broadcast with starter 2x2, a... C. Edwards, D. Ruiz diaz |
841. Independence of Crop Yield and Nitrogen Rate Across SitesHistorically soil fertility specialists in the North Central States of the USA have constructed nitrogen (N) rate recommendations based on ‘yield goals’ or ‘expected yield’. Within the past ten years, there has been a general realization by soil fertility researchers that within a site or field there is a relationship between N rate and yield; however, because of soil and weather differences between sites there is no relationship in N rate studies with a large number o... D. Franzen, L. Sharma, H. Bu, E. Schultz, J. Breker, A. Denton |
842. Nitrogen Fertilizer Management for Wheat Under Dual Purpose Grazing and Grain ProductionDual purpose winter wheat is a common system used in many regions of the Southern Great Plains. The objective of this study was to i.) evaluate the interaction of wheat grazing management and soil and fertilizer nitrogen requirements with emphasis on dual purpose wheat. This study was established at three locations during the 2015-2016 growing season. Experimental design was a randomized split block design with 16 treatments including simulated grazing and grain only treatments and varying ra... T. Gardner, D. Ruiz diaz, C. Edwards |
843. N-Fertilizer Recovery Efficiency by Corn Using Controlled Release UreaLimited research has been conducted on the use of 15N-labeled controlled release urea fertilizers under field conditions for corn production. The objectives of this study were to: 1) evaluate the fate of N derived from a blend of two enhanced efficiency N fertilizers in corn plants throughout the growing season; and 2) to determine the N recovery efficiency of the two N sources from a blended application. A field study was conducted during the 2015-2016 growing season at Iracemápo... H. Gonzalez, D. Ruiz diaz, C. Filho, P. Trivelin |
844. Mine the Data Not the Soil: Big Data Considerations for Soil FertilityFarm data has become a current topic in agriculture as well as other industries and is known as ‘big data’. Debate regarding the ownership of the data and who should receive value from the use of that data are hotly debated. This paper dispels many of the myths of big data in agriculture and offers insights into best management practices with respect to using data isolated to a given farm as well as within a larger community. A substantial portion of this paper was adapted from Gr... T. Griffin |
845. Soybean Yield Response to P Fertilizer Placement as Affected by Soil Parameters: A ReviewIn the last decades, several studies were conducted to evaluate more efficient P fertilizer management with emphasis on placement. Many of these studies report contrasting results, suggesting that a general recommendation may not be appropriate and specific factors of soils, crops, and weather should be considered. A literature search was completed using Google Scholar, and published papers that met our selection criteria included 62 experiments, with 95 site-years. Approximately 9.8% of the ... F. Hansel, D. Ruiz diaz, L. Rosso |
846. Nitrate-N Loss Reduction: Scale of In-Field and Edge-of-Field Practice Implementation to Reach Water Quality GoalsStates in the Mississippi River Basin have developed state level nutrient reduction strategies in response to the 2008 Hypoxia Action Plan. The Iowa Nutrient Reduction Strategy was released in 2013 and the Nonpoint Source Nutrient Reduction Strategy Science Assessment reviews potential practice performance in reducing downstream nutrient loss and the scale of implementation that would be necessary to reach the Hypoxia Action Plan goal of a 45% reduction in riverine Nitrogen and Phosphorus. To... M. Helmers |
847. Nutrient Management Practices for Water QualityField to Market®: The Alliance for Sustainable Agriculture Field to Market® is a diverse alliance working to create opportunities across the agricultural supply chain for continuous improvements in productivity, environmental quality, and human well-being. The group provides collaborative leadership that is engaged in industry-wide dialogue, grounded in science, and open to the full range of technology choices. ... A. Herges |
848. Response of Continuous Corn to Varying Rates and Placements of Starter FertilizerPrevious research has shown that starter fertilizer, a small amount of fertilizer placed with or near the seed at planting, often accelerates early season growth and increases biomass production, but does not always increase grain yield in corn (Zea mays L.). Our objective was to evaluate the effects of starter fertilizer on crop growth and development, as well as grain yield and moisture in continuous corn cropping systems. Treatments consisted of no fertilizer applied at planting (Cont... C. Hornaday, J. Camberato, R. Nielsen |
849. Influence of Source and Particle Size on Agricultural Limestone Efficiency at Increasing Soil pHExcessive soil acidity is known to have potential negative impacts on crop production. The chemical and physical characteristics of a liming material determine its capacity to neutralize soil acidity. The calcium carbonate (CaCO3) equivalent (CCE) and estimates of particle size impact on the efficiency at increase soil pH are considered when assessing a material’s liming value. The reaction of limestone particles within the soil depends largely on the soil pH and the material surface ar... J. Jones, A. Mallarino |
850. Prediction of Corn and Soybean Grain Yield Response to P in Minnesota Using the Haney H3A and Mehlich-III TestsMinnesota soils are highly variable in P availability due to the wide range of chemical properties. Currently, two soil tests are used to measure soil P in Minnesota, the Bray-P1 for pH<7.4 and the Olsen P for pH>7.4. The purpose of this study was to correlate crop response in corn and soybean rotations to the Bray-P1, Olsen, Mehlich-III, and Haney H3A extractions and to determine critical concentrations for each extraction method. Soil P tests were also correlated with one another to d... D. Kaiser, L. Leverich, J. Vetsch, J. Strock |
851. Effects of Applied Soil Micronutrients on Corn and Soybean Yields in Eastern South Dakota EnvironmentsMicronutrients although taken up by plants in small quantities, their deficiencies can have significant detrimental effects on grain yield. As growers aim for maximum corn and soybean yields, availability of micronutrients in agricultural market both as individual source or combined with other secondary nutrients have also increased. However, effects of micronutrients on corn and soybean grain yields are not well documented for South Dakota (SD) soils, and growers seem to be concerned if appl... D. Karki, A. Bly, S. Berg |
852. Project Sense: Sensors for the Efficient Use of Nitrogen and Stewardship of the Environment. An On-Farm Research Effort to Increase Adoption of Sensor Based N ManagementLow nitrogen use efficiency (NUE) has been attributed to several factors including asynchrony between nitrogen (N) fertilizer application, crop demand, and spatial variability (Shanahan et al., 2008). Sidedress applied N synchronizes crop uptake demand for N, but does not address the spatial and temporal variability that exists in a field year to year. Active crop canopy sensors provide an ability to monitor and respond to spatial and temporal N variability for a given field. A three-year pro... B. Krienke, R. Ferguson, J. Luck, L. Thompson, J. Parrish, N. Mueller, T. Mieno, J. Crowther, T. Shaver, T. Ingram, D. Krull, K. Glewen |
853. Phosphorus and Potassium Response In No-Till Corn and Soybean ProductionCurrent UWEX fertilizer recommendations and plant analysis interpretation guidelines were developed prior to the release of GMO corn. There is some concern amongst University soil fertility specialists and industry agronomists that corn and soybean response to P and K fertilizer applications may be different with modern corn hybrids and soybean varieties. In addition, in the UW recommendation system, an estimate of the amount of nutrients removed in the harvested portion of the crop is used t... C. Laboski, T. Andraski |
854. Starter Fertilizer Slows the Movement of Corn Roots Across the RowApplications of starter fertilizer may alter the root morphology of young developing plants by causing lateral roots to proliferate when the root system enters the highly concentrated fertilizer band. This may affect the timing of root movement across the row when starter fertilizer is used. The timing of root movement across the row was determined by placing 20 12-inch-long perforated cylinders vertically in the soil at the V2 leaf stage. The cylinders were placed approximately every 15&rdqu... J. Lee, J. Camberato, R. Nielsen |
855. What Can Long Term Experiments Provide for Improving Phosphorus and Potassium Management?Agricultural research utilizes both short-term and long-term experiments. Short-term experiments provide useful information on how a system is affected at the time of management changes, and evaluate short-term responses by the soil or crop. Agricultural systems are complex systems with multiple components that operate on different time scales of response, however. Therefore, the initial response of either the whole system or individual components may not necessarily indicate the direction or... A. Mallarino |
856. Residual Effects of Nitrogen Fertilization on Soil Nitrogen Pools and Corn GrowthNitrogen (N) fertilization of corn (Zea mays L.) may increase, decrease, or not affect the N supplying capacity of the soil. Six field-scale corn N rate trials were established in corn-soybean rotations in diverse soil types across Indiana. Six N rates ranging from about 25 to 270 lb N ac-1 were replicated 4 to 6 times at each site and re-applied to the same plots for each of four corn crops. In the fifth corn season, 2015, half of the replications at each location were sup... M. Moser, R. Nielsen, J. Camberato |
857. Comparative N and Dry Matter Dynamics in Corn Ears, Stems, and Leaves During the Critical Period After Early and Late-split Sidedress NThere is currently great interest in the possible agronomic and environmental benefits of split N applications that include a late vegetative sidedress timing. The objective of this study was to determine the impact of N rate and timing of N application on the accumulation of N and dry matter in the ears, stems, and leaves of corn during the critical period (encompassing the period two weeks before to two weeks after silking) in order to understand the differing sensitivity to N stress in the... S. Mueller, T. Vyn |
858. Nitrogen Fertilizer on Soybeans: Are We Making Progress?The recent drop in the price of soybeans has dampened enthusiasm for applying inputs of uncertain value to crops, but application of fertilizer N during the season is often reported by soybean yield contest winners as a way to increase yields, and some producers have adopted this as a practice. As soybean yields have increased, the amount of N required by the crop has increased. Soybean seed with 36 percent protein is about 5.75% N, and a bushel of soybean grain contains about 3 lb.... E. Nafziger, J. Vonk |
859. Evaluation of Four Iron Sources for the Control of Iron Deficiency Chlorosis in SoybeanIron deficiency chlorosis (IDC) is a destructive disorder of soybeans grown on calcareous soils in the North Central region. Certain chelates are effective at preventing IDC, but the quality of commercial-grade materials varies. The objective of this greenhouse study was to compare the ability of four commercial iron fertilizers to prevent IDC in soybeans. The four sources were a high-quality FeEDDHA product (FeEDDHA-1), an FeEDDHA product of lower quality (FeEDDHA-2), FeEDDHSA, and FeHBED. T... H. Ohm, R. Goos |
860. Winter Wheat Growth and Grain Yield Response to Individual Agronomic InputsProducers’ interested in optimizing wheat (Triticum aestivum L.) growth and yields have adopted intensive (i.e. high-input) wheat management systems in Michigan. Additional research is required to evaluate growth, grain yield, and profitability of multiple and individual agronomic inputs. An omission field trial was initiated in Lansing, MI during 2015 to evaluate the response of soft red winter wheat to six agronomic inputs in enhanced (high-input) and traditional (low-input) ... D. Quinn, K. Steinke |
861. Fall Nitrogen for Winter Wheat Production?Fall nitrogen (N) applications are typically not recommended in Kentucky unless previous corn yields exceed 30 bu/A more than expected or when wheat is planted later than optimal in combination with a wet fall. In 2016, much of Kentucky experienced this combination of yield and environmental conditions. A study was initiated to test the need for fall applied N and how much fall N may be needed. Wheat was planted at recommended (normal) dates and then at dates that would be considered later th... E. Ritchey, J. Grove |
862. Impact of Nitrogen Application Timing on Corn ProductionWater quality issues have renewed interest in timing of nitrogen (N) application as a means to improve use efficiency in corn and reduce losses. Improved economic return is also desired as N fertilization is one of the most costly inputs to corn production. Time of fertilizer application is a component of the site-specific 4R nutrient management stewardship programs. In Iowa, the Nutrient Reduction Strategy has a 7% (37% std. dev.) nitrate-N reduction with a 0% (3% std. dev.) corn yield chang... J. Sawyer, D. Barker, J. Lundvall |
863. Variation in Internal N Efficiency of Corn and Impact on Yield-Goal Based N RecommendationsInternal N efficiency (IE) is defined as bushels per acre (GY) produced per pound of N per acre (PMN) in the plant at physiological maturity (R6). Internal N efficiency defines the required amount of plant N content at R6 in a yield-goal based N rate recommendations (currently used in 30 U.S. states) and several commercial N recommendation models. Commonly IE is assumed to be constant at an approximate value of 0.8 bu lb-N-1 in yield-goal based recommendations. Our research objective was... M. Shafer, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, R. Nielsen, J. Sawyer, J. Shanahan |
864. In-Season Soil Nitrogen as a Predictor of Corn Grain YieldCorn (Zea mays L.) grain yield is closely linked to plant available soil nitrogen (N). Our objectives were to (i) examine the influence of N rate, source, and time of application on N use efficiency with relation to grain yield and total plant N uptake, and (ii) evaluate in-season soil N testing as a tool to determine N rate needs and predict grain yield. During the 2014-2015 growing seasons, 12 fields across Minnesota varying in soil and climate conditions received 1) pre-plant urea (0 to 20... J. Spackman, F. Fernandez |
865. Soil Health: Approaches in Fertility ManagementInconsistent grain yield and in some cases variable yield response to fertilizer inputs suggest improving fertility management strategies with greater emphasis towards resilient cropping systems may also improve nutrient efficiency. The soil microbiome may affect nutrient mineralization, nutrient movement to roots, disease incidence, and other specialized relationships (e.g., nodule formation in soybean (Glycine max L.)). Although within-field grain yield variability has correla... K. Steinke |
866. Evaluation of Polyhalite as a Source of Potassium and Sulfur for a Corn-Soybean Rotation in MinnesotaPolyhalite contains K, S, Mg, and Ca which could be used as a source of nutrients for crops in Minnesota. The objective of this research was to determine if polyhalite can utilized within for a two-year corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation. Field studies were established at two locations in Minnesota with the soil test K of <120 ppm (0-6 inch sample extracted with 1M NH4OAC) and where a response to S was expected. Treatments were polyhali... A. Sutradhar, D. Kaiser, C. Rosen |
867. Chemistry of Soil Phosphorus - Agronomic and Environmental ImplicationsTo be available for uptake by crop plants or to stimulate algal growth in a eutrophic environment, P must in a dissolved form. Therefore, in the absence of soil erosion, chemical processes that can transfer phosphate ions from the soil solution to the solid phase can limit P bioavailability and mobility. These processes include exchange, adsorption, and precipitation reactions. This presentation focuses on how local fluctuations in soil water content, solution pH, redox potential, and dissolv... M. Thompson |
868. Respiration as a Measure of Soil Health: Challenges and OpportunitiesIn recent years, respiration has become a commonly-used soil health metric. It has been used as a standalone predictor of soil N supplying capacity and in conjunction with other metrics to assess overall soil health. However, the sources of variation underlying respiration itself have not been thoroughly assessed. We show that across growing regions in California, respiration was unable to accurately predict soil N supply. The R2 values were much higher in fields that had received a rece... J. Wade, S. Culman, T. Hurriso, W. Horwath, R. Miller |
869. Lessons learned from long-term P & K trialThis presentation will disucss corn and soybean response to P and K over 10 years in a notill system. ... C.A. Laboski, T.W. Andraski |
870. Reevaluating Potassium Recommendations for Soybean Production in KentuckyFertility recommendations from land grant universities are typically lower than private soil test laboratories and lead producers to question the adequacy of current recommendations. Further, soil samples analyzed at UK Regulatory Services Soil Testing Laboratory indicate that average state-wide soil test potassium (K) levels are declining approximately 1 lb K/A/year. The reason for this decline is not known, but some suspect it might be due to increased crop yields while maintaining historic... E. Ritchey, J.H. Grove, J.M. Mcgrath |
871. Relationship of in-season soil nitrogen concentration with corn yield and potential nitrogen lossesModeled or measured soil mineral N (SMN) levels during the corn growing season have been used to set sidedress N rates, but there has been little research linking SMN levels at different growth stages to yield to help guide this process. The degree to which SMN level influences the risk of N losses is also not known. Data from 32 site-years of field experiments in Illinois (2015–2018) that included 12 combinations of N fertilizer rate, timing, and source, were used to evaluate... G. Preza-fontes, E. Nafziger, L. Christianson, C. Pittelkow |
872. Role of Postemergence Sidedressed Fluid Potassium Fertilizer to Complement Preplant Fertilization in Corn-Soybean RotationsRole of Postemergence Sidedressed Fluid Potassium Fertilizer to Complement Preplant Fertilization in Corn-Soybean Rotations Antonio P. Mallarino and Louis B. Thompson-Ansorena Iowa State University ABSTRACT Farmers and crop consultants of non-irrigated areas of the north-central region have been asking questions about possible use of post-emergence fluid potassium (K) fertilization to complement preplant fertilization. Sidedressing N for corn is c... A.P. Mallarino, L.B. Thompson-ansorena |
873. Corporate Sustainability Initiatives and Their Interface with Crop Nutrient ManagementAn increasing number of corporations are establishing sustainability initiatives. For ag/food companies, these interface with nutrient management mainly via nitrogen—a lot of carbon dioxide is produced during nitrogen fertilizer manufacture, and some nitrogen fertilizer is converted to nitrous oxide (a potent greenhouse gas) after application. A corporate sustainability representative, a nitrous oxide expert, and a farmer will present their views and then take ques... P. Carter, R. Sirolli, G. Robertson, M. Hora |
874. Working Toward a National Soil Test P and K Database and Recommendation SystemSoil test recommendations differ across state lines and across regions—sometimes these differences are large. They may be due to differences in soil and climate, but they may be due to historical accident. This presentation will explain a new project to gather all available soil test P and K calibration data nationally, to create a transparent framework to house this data and make it available, to conduct new calibration research to fill in gaps, and to create reco... D. Osmond |
875. Oh, K? When is Too Much K Too Much?Potassium is required in large amounts by crop plants and is a staple fertilizer, mainly as KCl. Recent data across three midwestern states suggests that sometimes, especially at high rates and shortly before planting, KCl may have negative impacts on corn and/or soybean yields. Three researchers will briefly describe their research in this area and then field questions from the audience. - Kaiser Twenty-nine potassium (K) fertilizer trials were conducted in ea... D. Kaiser, S. Casteel, D. Franzen |
876. 35 years of nitrogen researchThis presentation will hit the high points of 35 years of nitrogen research in corn, wheat, and cotton, focusing mostly on timing and rate. With all three crops, applying no N early did not hurt yield—thus no benefit to splitting N. Exception is wheat with low tiller density at greenup, which needs early N Later N applications often gave higher yield than earlier applications for corn and whea... P. Scharf |
877. Should we incur a loss by interseeding in sugarbeet ?The Red River Valley of North Dakota and Minnesota contributes with half of the nation’s sugarbeet (Beta vulgaris L.) production. Interseeding cover crops within sugarbeet has the potential to reduce the impact of soil disturbances. Field experiments were conducted to evaluate the impact of cover crop interseeding time and species on sugarbeet root yield, sugar content, and economic profitability during 2018 -20 growing seasons. Cover crops were first interseeded in June and second... S. Sigdel, A. Chatterjee, M. Berti |
878. What’s Working (or Not) in Winter WheatMichigan winter wheat growers produce some of the greatest soft red and white wheat (Triticum aestivum L.) grain yields in the U.S. with statewide averages > 71 bu A-1 since 2015. Interest in enhanced management strategies continues to increase but maintaining or improving profitability has become increasingly important as broad implementation of enhanced management has not produced consistent yield gains. Increased demand for wheat straw has cast greater foc... K. Steinke |
879. Corn Nitrogen Fertilizer Management Practices in Eastern South DakotaThe adoption factors of N best management practices (BMPs) that can lessen N loss needs to be understood to help increase adoption rates. Understanding the local, small-scale factors (geographic location, tillage type, and farm size) that influence the use of N BMPs will help nutrient management professionals provide the research and information needed to increase the use of N BMPs. South Dakota (SD) survey data from 465 producers was used to examine the above local, small-scale factors that ... J.D. Clark, A. Bly, P. Kovacs, J. Ulrich-schad |
880. Independence of Yield and N-Rate, and Use of EONR in N Fertilizer Recommendations in North DakotaEvidence for the independence of N-rate and yield comes from the improved relationship of N-rate with relative yield compared to raw yield in corn, spring wheat and sunflower N-rate experiments in North Dakota. Relationships were also improved in corn by grouping experiments by regional location and whether the soils are high clay (>40% clay) or not, and discriminating between long-term no-till (6 years or more continuous no-till) or conventional till. In spring wheat, regional differences... D. Franzen, H. Bu, L. Sharma, E.C. Schultz, A. Wick, B. Goettl, M. Berti |
881. Impact of Site-Specific Variability on the Effectiveness of Active Canopy Sensors for In-Season N Management in CornIn-season nitrogen (N) management in corn guided by active canopy sensors is often associated with higher yields, profit and nitrogen use efficiency (NUE). However, these benefits could vary from field-to-field and year-to-year. These inconsistent relationships between technology and benefits represent a major challenge for increasing adoption of sensor-based N application in corn. Thus, a better understanding of which site-specific factors determine positive benefits from sensor-based N appl... L. Puntel, J. Luck, L. Thompson |
882. Fertilizer Manufacture - Converting Nature's Nutrient Storehouse to Plant NutritionNorth American farmers rely on reliable supply of key fertilizer inputs to maintain productivity and profitability. Nitrogen fertilizers are produced from atmospheric nitrogen gas, while phosphate and potash fertilizers are mined from major North American deposits as well as others around the world. All the major fertilizers are supplied, in large part, by North American producers from domestic production supplemented by some imports from international producers. Nitrogen prod... A. Blaylock |
883. The MRTN Approach: Past, Present, and FutureThe method of using crop N response data assimilation, now called the “MRTN approach”, was conceived at a September, 2004 meeting in Bettendorf, Iowa of scientists from several Corn Belt states. This meeting was prompted by findings in field trials that showed substantially lower optimum N rates than those based on using corn yield goal to predict crop N needs; most also showed no correlation between EONR and yield at EONR across trials. The MRTN method is straightforward: yield d... E. Nafziger, J. Sawyer |
884. Should Potassium Chloride be Applied to Soybean?Potassium chloride represents 98% of potassium sales in Minnesota. Potassium chloride contains 50% of chloride by mass. Research in the southern U.S. shows excess chloride is known to result in decreased soybean (Gylcine max var Merr.) yield. The objective of this study was to determine whether chloride impacts soybean yield in northern growing regions and evaluate the effect of rate (100 or 200 lb K ac-1) , fertilizer (K or Cl) source (none, KCl, K2SO4... D. Kaiser |
885. Evaluation of Soil Test Methods and Early Tissue Analysis to Assess Potassium Response in SoybeanMultiple soil test methods has been evaluated as diagnostic tool for potassium management in soybeans. This study compared different soil test K methods (STK) and evaluate the correlation to soybean yield and K uptake response in low testing soils, and assessed tissue analysis as alternative for in-season correction options. ... D. Charbonnier , D. Ruiz diaz |
886. Some Thoughts on Nutrient Mineralization and Cycling in No-Till SystemsHigh post-harvest residue accumulations (10+ tons/acre) often occur in crop sequences involving high yielding corn, spring wheat and soybean. Over the last decade, we have conducted several studies that show that N or P availability may be suppressed either through slow residue decomposition, slow mineralization or immobilization. Although several states provide fertilizer recommendation adjustments for no-till and for high residue accumulations, the recommendations are sometimes contra... L. Cihacek, R. Alghamdi |
887. Implementation and Validation of the MRTN Recommendation System in WisconsinThe maximum return to N (MRTN) recommendation system for corn was implemented in Wisconsin in 2006. In many ways, MRTN is a dynamic extension of N response-based N recommendation that was implemented in 1991. Vanotti and Bundy (1994) demonstrated the utility of using N rate response trials as the basis for N recommendations. And that grouping soils by N response and soil characteristics was useful could improve N recommendations. In Wisconsin recommendations, relative yield potential was qual... C. Laboski |
888. Farming the Data: New Paradigm in Precision AgriculturePrecision Agriculture has been around for over two decades. The first decade had a strong focus on quantifying spatial variability in soils, the second decade spent significant time on science and technology of precision management of nutrients. Now, with increasing adoption of Precision management techniques and practices there is interest in harnessing the power of data to grapple the new paradigm of making management decision based on evidence. The success of future farming practices, outp... R. Khosla |
889. A New Frontier Below the Horizon: My Work with Pivot Bio BiologicalsSymbiotic Nitrogen (N) fixation is an amazing process that harnesses the power of two organisms (a legume and rhizobium) to mutually benefit one another. However, the process of biological N fixation or the reduction from dinitrogen gas to ammonia/ammonium via the nitrogenase enzyme is an expensive one. The relationship between host plant and rhizobium hinges on the free exchange of N for carbon and other metabolites. Nitrogen fertilizer is often the most limiting nutrient for cereal crop pro... T. Roberts |
890. Chloride from Fertilizer and Water Pollution -Should I Be Concerned?Chloride is a more recently recognized pollutant of concern in many states. In Minnesota, 50 lakes and stream reaches are impaired for chloride, 30% of shallow monitoring wells exceed the secondary health standard, and chloride is on the rise in many other waters. Chloride is toxic to aquatic life, can contaminate groundwater, and has additional environmental impacts. How much does fertilizer contribute? This presentation will cover chloride sources... C. Dindorf |
891. Advances in North Dakota Soil Fertility 2022Following years of accumulating data from field studies using the GreenSeeker™ and Holland Scientific Crop Circle™ active optical sensors, algorithms for use in spring wheat for in-season N application for yield, and immediate post-anthesis N application for protein enhancement have been developed. Both algorithms require an N non-limiting area as a standard. The algorithm for protein enhancement considers whether a cultivar has inherent high protein or lower protein characteristi... D. Franzen, H. Bu, M. Berti, A. Wick |
892. Practical Farmers of Iowa On-farm Research ProgramPractical Farmers of Iowa (PFI) has been leading and conducting on-farm research since 1987. The organization has staff scientists to help design experiments based on questions from participating farmers. Farmers are cooperators in research and they often collaborate with other farmers on the same project. Ideas for projects are considered at the annual Cooperators’ Meeting in December each year. Cooperators describe what was done on their farm, why they did it, and what they found. The... S. Gailans |
893. The Ammonia RainbowAgriculture has been identified as a major contributor to atmospheric carbon dioxide with nitrogen fertilizer production as a key component. Recent scrutiny of nitrogen production processes has identified ammonia production processes to reduce carbon output from traditional Haber-Bosch processes. These different ammonia production processes are often described with color descriptions to designate the processes used and qualitatively identify their carbon footprint, such as “green ... A. Blaylock |
894. Landscape Position Affects Management Decisions for Crop ProductionLandscape attributes including topographic positions, slope, curvature, elevation, water flow direction and water flow accumulation are well documented in the literature for their effects on crop productivity. Topography influences crop growth and yield by impacting water and nutrient movement in the soil. Under dryland crop production systems, water availability generally depends on topsoil depth, soil organic matter, and curvature of the micro-topography. To improve overall productivity of ... G. Singh , K. Nelson, G. Kaur |
895. N, S and Micronutrient (B + Zn) Interactions in Soft Red Winter Wheat NutritionThis work is intended to answer certain questions that result from the implementation of a multi-element wheat nutrition program. Nitrogen rate is a fundamental driver of wheat yield and quality. However, the impact/value of S or the micronutrients, which are likely components of a more integrated wheat nutrient management program, is not clear.The main study design included 4 rates of N (40, 80, 120 and 160 lb N/acre), 2 rates of S (0 and 10 lb S/acre), and 2 rates of the micronutrient &lsqu... J. Grove, E. Ritchey, J. Shockley |
896. Utilizing Fertilizer and Fungicide Strategies to Enhance Winter Wheat Grain and Straw ProductionThe establishment and overwintering success of Michigan winter wheat (Triticum aestivum L) are often determining yield factors but identifying both autumn and in-season practices that may enhance yield and economic return can be difficult. Additional demand for straw has growers considering inputs that may not only affect grain yield potential but also overall biomass production and serve as another means to improve profitability. Recent research has documented significant grain and ... K. Steinke, L. Suplito, M. Chilvers |
897. Carbon Credit and Sequestration in Agroecosystems; Lessons from Trials in Southern IllinoisA carbon (C) credit is the attribution of net CO2-C equivalent which can be used to decrease climate forcing through a given practice or farming system for a given unit time. Carbon credits allow industries to purchase C that is produced on a farm (i.e., offsets). Carbon can be captured in two ways; (i) by capturing and reducing greenhouse gasses (on a CO2-C equivalent basis), and/or (ii) by increasing soil organic C stocks. Therefore, to enable C credits in the agricult... A. Sadeghpour, A.M. Weidhuner, G. Burkett, O. Zandvakili, O. Adeyemi, C. Kula, J. Berberich, J. Pike, A.J. Margenot |
898. Integrated and Impactful Research and Extension Through Digital On-farm ResearchAdvancements in digital agriculture tools have increased the scale and complexity of agricultural challenges which can be addressed through on-farm research. On-farm research has the potential to center farmers in the discovery and innovation process and integrate the research, extension and teaching missions of the university. Synergistic partnerships with industry advance technology adoption. Thompson will discuss the opportunities to leverage the changing landscape of on-farm experimentati... L. Thompson |
899. Agronomic Management of Nitrogen to Reduce N2O Emissions in ManitobaNitrous oxide (N2O) emissions from soil accounts for about 20% of Manitoba’s total greenhouse gas (GHG) emissions. Numerous and recent field research has evaluated these emissions as influenced by nitrogen (N) management practices – such as use of enhanced efficiency fertilizers (EEFs), fertilizer placement and timing, use of legume and cover crops and organic farming. Several practices result in considerable decreases in N2O emissions, across a w... J. Heard, M. Tenuta |
900. Cover Crops, Manure, and NitrogenFall seeded cover crops can offer soil and water conservation benefits to dairy-based cropping systems. However, uptake by these fall cover crops can also limit nitrogen availability from the manure to the next crop. Field research projects throughout the state of Wisconsin have been conducted to assess how cover crop specie, biomass, and N uptake influence the amount of supplemental N needed to fertilize the following corn crop to maximize yield. Fall seeded cover crops that winter kill (spr... M. Ruark, A. Waggoner |
901. Pelleted Lime Application Strategies for Iowa Corn and Soybean ProductionResearch has shown inconsistent results about the efficiency of pelleted lime at increasing soil pH or crop yield compared with aglime. Our previous Iowa research (2015-2016) showed that pelleted lime manufactured with limestone from northern Iowa quarries attained maximum soil pH with the same rate and at the same time than finely ground calcium carbonate, but more time was needed for aglime. However, there were no yield differences between the sources for corn-soybean rotations when one-tim... A.P. Mallarino, M.U. Haq |
902. Design, Wrangling and Analysis of an On-farm Strip Trial. Iowa Soybean Association MethodologiesIowa Soybean Association (ISA) has conducted over 4,000 replicated on-farm trials over the past 15 years. During this time, we have developed our own methodologies and approaches to the data. In this talk we review step by step ISA approaches to a replicated strip trial involving 5 nitrogen rates including trial design, data wrangling, data analysis and machine learning approaches. The talk concludes with discussion on some difficulties in on-farm research with an appeal to the science commun... S. Nelson |
903. Comparing Yield Goal and Maximum Return to N Based Methods in Predicting Corn Economic Optimal Nitrogen RatesThere are two main N rate recommendation systems used in the U.S.–Yield goal and maximum return to N (MRTN). The current yield-goal based system for calculating corn N rate recommendations in SD has not been evaluated for accuracy since 2013. Therefore, the objective of this project was to 1) evaluate the accuracy of the current yield goal-based equation and 2) create a database of N response trials and evaluate the accuracy of using the MRTN approach for predicting N rate requirements.... J. Clark, P. Kovacs, A. Bly, C. Graham |
904. Summary of Regional Studies in Corn on Selected Commercial Asymbiotic N-fixing Organisms and Suggestions for Companies Developing Similar ProductsThis presentation will provide a brief summary of N rate studies from the North Central region which include treatments with selected commercial asymbiotic N-fixation organism products. Farmers are encouraged to remain curious of new products, but also skeptical; testing the products of interest through replicated strip trials their farms to determine whether the products have value to their operation. In conversations over the past several months with companies interested in developing asymb... D. Franzen |
905. Fertilizer Industry Update – Markets, Trends, and New DirectionsThe fertilizer industry was characterized, perhaps above all else, as volatile. We saw near record prices as supply chains were affected by war in Ukraine, international sanctions, and high production costs. Across the industry, fertilizer manufacturers and suppliers seek to cut operating costs to cope with rapidly falling prices. We will review key market drivers and other industry trends. ... A. Blaylock |
906. Ag Economy and Policy Outlook for 2024We will explore the factors currently shaping the ag economy and the various sectors that drive economic growth in the sector. We will investigate the connections among feed, fuel, and export markets and examine potential changes to federal agricultural policy (i.e., the Farm Bill). We will discuss the potential for agricultural profitability over the next few years and outline the challenges to reaching robust economic gains. ... C. Hart |
907. Is There an Optimal Source of Sulfur for Corn?Sulfur has become a common nutrient applied to corn in the Corn Belt. While research has demonstrated that sulfur can greatly increase yield, the source of sulfur offered to farmers by retailers can vary. Sulfur is only taken up by corn in the sulfate form while sulfur fertilizer source can contain sulfate that is readily available to plants or elemental sulfur which needs to be oxidized to sulfate before it is taken up by a crop. Four long-term research sites were established in Minnesota us... D. Kaiser |
908. Optimizing Nitrogen Management for Sustainable Production of Furrow-Irrigated Corn in Nebraska PanhandleLosses of nitrogen (N) via leaching to groundwater and greenhouse gas emissions pose an environmental and human health threat. The risk for environmental N losses, particularly nitrate leaching loss, is greater in furrow-irrigated fields than those under drip or sprinkler irrigation. Furrow irrigation accounts for 30% of total irrigated acres in Nebraska and approximately 36% in the US. However, much of the efforts for N management improvement are concentrated on sprinkler or drip systems. Th... B. Maharjan, D. Ghimire |
909. Re-evaluating Phosphorus and Potassium Management for Corn, Soybean, and Wheat in OntarioIn Ontario, long term trends show decreasing soil test P and K levels as high crop yields in corn, soybeans, and wheat remove more nutrients than are being replaced through nutrient application. Deficiencies or insufficient available P and K from either the soil, fertilizer applications, or both, could mean that modern yields of these crops are not fully reaching their potential. A long-term project was established between 2010 and 2012 on 4 field sites in Ontario to compare two different fer... D. Hooker, C. Elgie |
910. Assessing Sulfur Response, Utilization Efficiency, and Diagnostic Tools for Corn in KansasEfficient sulfur (S) utilization is crucial for crops' productivity and the sustainability of agricultural systems. This study aims to evaluate the effect of sulfur application on corn production across various Kansas sites and determine how sulfur fertilization affects different growth parameters and diagnostic tools for corn. The study was conducted over the 2021-2022 growing seasons, with a comprehensive field experiment carried out across 26 sites in Kansas. A randomized complete bloc... G. Roa , D. Ruiz diaz |
911. Potentials and Constraints for Successful BioinoculantsBiologicals for agricultural production are receiving much interest, investment, and research. Biologicals offer replacements for chemicals. However, understanding the abiotic and abiotic interactions that affect survival and activity is needed to assess performance. Abiotic factors include soil properties, soil moisture, and temperature. Biotic factors include compatibility with native microorganisms and root characteristics. Given these factors, performance will be more variable than chemic... C.W. Rice |
912. Carryover Effects of Sulfur Fertilization from One Cropping Season to the NextCorn and soybean grain yield increases with S fertilization are not uncommon in Indiana. Low rates of S fertilizer (<15-20 lb S/acre) are needed to maximize grain yield response. We found that sulfate-S fertilizer applied to silt loam or heavier textured soils in one cropping season provided S to the crop grown the next season more often than not. At some S responsive locations, S applied the prior season at 15 to 20 lb S/acre produced yields of the second crop equivalent to crop yields wi... J. Camberato, R. Nielsen |
913. Evaluation of Instinct II and Radiate on Soft Red Winter Wheat in Northwest OhioProducers in Northwest Ohio are encouraged to purchase various additives for urea-ammonium nitrate (UAN) with the expectation to increase grain yields; however, they have limited information on the benefits of these products except what was provided by the selling company. Two products that were commonly promoted were Instinct II, a nitrification inhibitor, and Radiate, a growth regulator. A three-year study was completed at the OARDC Northwest Agricultural Research Station near Custar, Ohio ... E.M. Lentz |
914. Overview of Biostimulant Classification and Industry PerspectiveThere are many but what is the definition of biostimulant? How are these products categorized? We will start off with definitions of commonly used terms around biostimulant products used in agriculture. The current categories in which biostimulant products fit, or do not fit into, are continually evolving as industry and regulatory work towards fine-toning definitions. As more products become commercially available, producers need to be aware of their advantages, as well as challenges, to max... C. Preston |
915. Managing Phosphorus and Potassium Soil Test Levels and Effects on Corn Response to Nitrogen with Variable Crop PricesAnnual fertilizer investment for corn-soybean rotation systems represent a significant portion of annual input costs. Variable crop and fertilizer prices raise questions of which macronutrients can be prioritized or cut from fertilization programs. Corn yield response to N fertilization is affected by soil N supply, crop N demand, and interacting factors that affect crop N use, such as phosphorus (P) and potassium (K) supply. The later also influencing soybean yield in the rotation. To invest... J. Jones |
916. The Three-Legged Stool: Nitrogen, Environment, and Crop ProductionNitrogen, crop production, and environment are interrelated. The presentation will discuss recent and ongoing studies in Minnesota aimed at understanding how to manage nitrogen efficiently to enhance corn production while minimizing negative environmental impact. Realizing that overemphasizing one component or underemphasis another creates instability, just like adding or cutting a piece of a leg in a three-legged stool, this research is trying to find the "sweet spot" where each of... F. Fernández |
917. Is Field Crop Contamination with Heavy Metals an Emerging Concern?Heavy metal contamination of food, particularly food consumed by infants and young children, with arsenic (As), cadmium (Cd), and lead (Pb) is a major food safety concern in the United States and beginning to draw heightened regulatory scrutiny. Crop uptake of heavy metals also has high spatiotemporal variability due to multiple soil, field, climate and plant factors. Management strategies that minimize heavy metal uptake and translocation are needed. The objective of this field study was to ... K. Steinke, Z. Hayden, M. Suplito |
918. Wisconsin's Nitrogen Optimization Pilot Program: Highlights and Successes of On-Farm ResearchAccurately determining nitrogen fertilizer requirements for crops is challenging due to the wide variability introduced by management practices and environmental conditions. Over-application reduces profits and negatively affects water quality, while under-application can prevent yield targets from being reached. Conducting field-scale, on-farm research is a practical approach to better estimating optimum nitrogen rates on a field by field basis. In 2023, Wisconsin’s Department of Agric... M. Schauer, M. Ruark |
919. The Iowa Nitrogen InitiativeThe Iowa Nitrogen Initiative is a private-public partnership with a vision to provide Iowans with the best nitrogen science for the benefit of productivity, profitability, and environmental performance. We are working alongside agricultural service providers, farmers, and their advisors to design, execute, and interpret hundreds of coordinated on-farm, scientifically robust nitrogen rate trials every year. In 2024, we conducted more than 400 scientifically robust, fully replicated trials. Dat... S. Archontoulis, M. Castellano, M. Miller, M. Baum, R. Osman |
920. Cover Crops and Nitrogen Cycling in North Dakota Cropping SystemsCover crops have proven effective in reducing wind and water erosion, improving soil health, and capturing excess N in the fall to prevent leaching. Although the benefits of cover crops to soil health are widely reported, their impact on the yield of the following crops is not clear. The purpose of this North Dakota study was to determine the impact cover crops have on the yield of following corn (Zea Mays L.) and wheat (Triticum aestivum L.) crops along with quantifying nit... B. Goettl, D. Franzen |
921. Updating Nitrogen, Phosphate and Potash Rate Recommendations (AGR-1) for Kentucky Grain GrowersFor UK soil test lab users, soil test phosphorus (P) and potassium (K) have been slowly declining for several decades, suggesting recommended ‘maintenance’ rates (initiated in 1992) were insufficient. Adjusting for modern grain P and K concentrations and increasing yield-driven nutrient removal, we raised corn, soybean and wheat maintenance rates by 10 to 20 lb P2O5 and 10 to 30 lb K2O per acre, depending on the individual crop. Corn nitrogen (N) rate recommendations had not ... J. Grove, E. Ritchey |
922. Cover Crop Species and Planting Methods Influence on Corn N Requirement in Southern IllinoisIt is well established that planting cover crops prior to corn (Zea mays L.) can influence soil temperature, moisture, and nitrogen (N) dynamics. These changes in soil along with the effects of cover crop on corn plant population can influence corn grain yield and N requirement. Two strategies to facilitate corn establishment and avoid N immobilization especially in winter cereal cover crops is by mixing cover crop species or skipping the corn row (precision planting). A randomized c... A. Sadeghpour, C. Kula, G. Sener |
923. Corn Grain Yield Response to Nitrogen Rate Timing, Source, and Nitrification Inhibitor in MissouriNitrogen response depends on several factors including weather conditions, soil N supply capacity, previous crop in rotation, plant population, and fertilizer management practices. Fertilizer management practices include fertilizer rate, source, application timing, placement, and use of nitrogen stabilizer. In Missouri, the nitrogen fertilizer rate recommendations for corn are based on the yield goal equation. This equation includes the target plant population, pounds of nitrogen removed per ... G. Singh , K. Nelson, G. Kaur , J. Lory, M. Davis, L. Abendroth, H. Naumann, J. Calhoun, J. Chlapecka, W. Bradley, C.J. Ransom, R. Carson, P. Pal |
924. Phosphorus Management in the North Central Region: A Brief History, Current Unknowns and Next StepsThe history of phosphorus (P) reflects the history of agriculture in the North Central region. The yield-limiting importance of P, secondary to nitrogen, was recognized as at the turn of the 19th century. An overview of key developments and unfinished business following the picking of these low hanging fruit in the 20th century that face researchers, agronomists, and producers will be discussed. These include assessing P mobility, P sources from fertilizer versus soil, the concept o... A. Margenot |
925. Management Practices to Minimize Edge-of-Field Phosphorus LossManaging agricultural phosphorus (P) loss at the edge-of-field is critically important to inhibit the development of algal blooms in freshwater bodies. This is particularly important in the Northern Central region which has an abundance of freshwater lakes, agricultural lands, and harmful algal blooms. Edge-of-field monitoring data allows us to take a broad look at how management affects P export from cropland. Looking across a region over several decades also allows us to evaluate the non-ma... L. Pease |
926. Implication of Soil Conservation Practices on Fertility ManagementManagement practices for soil conservation are crucial for reducing soil degradation, and improving crop productivity and soil health. Often these practices are implemented after a problem has already occurred in a field. Therefore, because of changes in conservation management and year-to-year variability soil conditions are often not in a state of balance. Management practices for soil conservation are often studied to establish their impact on crop production, other soil properties, and th... F. Arriaga |