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1. A Combination of Soil Incubation and Chemical Extraction Tests Best Predicts Corn Yield Response to Fertilizer NitrogenSoil tests in general have served a critical role in the field of soil fertility for over half a century, and have helped to increase crop productivity and promote more efficient use of fertilizers on farms. However, N soil tests have limitations and chemical extraction tests have not predicted well the potentially mineralizable N supplied to corn over a growing season. Thus, these tests often do not accurately predict a corn’s yield response to fertilizer N. We explored 30 soil tests f... M. Mcdaniel, D. Walters, L. Bundy, C. Laboski, P. Scharf, R. Drijber, W. Horwath, J. Sawyer, J. Sawyer, M. Castellano |
2. Agronomic and Nutrient Management Strategies for Soft Red Winter WheatMichigan produces some of the greatest non-irrigated wheat (Triticum aestivum L.) yields in the United States. Enhancing or lengthening the greenness of the flag-leaf has been suggested as a method to improve photosynthetic capabilities and nutrient uptake. The objective of this study was to evaluate growth, grain quality, grain yield, and economic profitability for multiple agronomic and nutrient inputs across different production intensity levels. An omission field trial with four repl... S. Purucker, K. Steinke |
3. 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 ... |
4. Assessment of Plant Nitrogen Uptake with Late Fertilizer Applications in CornPrevious research in Kansas and other regions has shown that split applications of N fertilizer with early side-dress can increase yield compared to applications at planting in some site years. Split applications are typically done using the traditional side dress at the V6-V8 growth stage. However, late N applications (late-vegetative or early reproductive stage) is generating interest as one alternative to improve nitrogen use efficiency and possibly increase yields... D. Diaz, A. Stammer, F. Hansel |
5. Biological N Fixation on Soybeans: N Nutrition and Incidence on N BalanceSoybean [Glycine max (L.) Merr.] nitrogen (N) demand is partially met (50-60%) by the biological N fixation (BNF) process. Study of the “N-gap” (plant N demand minus N-BNF) and the partial N balance (fixed N in aboveground biomass minus N removed by seeds) are still unanswered scientific knowledge gaps. Focusing on these two components a review of 60 studies reporting on BNF was conducted in order to study the limits to which BNF can satisfy plant N demand. T... I. Ciampitti |
6. Can an Estimate of Mineralizable Nitrogen Improve Nitrogen Sufficiency Indexes?Combining the anaerobic potentially mineralizable N (PMNan) test with the pre-plant (PPNT) and pre-sidedress (PSNT) nitrate tests may improve N fertilizer guidelines for corn (Zea mays L.). Forty-nine corn N response experiments were conducted across eight states in the US Midwest (Illinois, Indiana, Iowa, Minnesota, Missouri, Nebraska, North Dakota, and Wisconsin) from 2014-2016. These studies were used to evaluate the effect of combining PMNan values from different soil sampling t... J. Clark |
7. Can Co-additives Alter the Phosphorus Fertilizer Reaction Pathways in P-Fixing Soils?In many calcareous and strongly weathered acid soils, only a small proportion of applied fertilizer P is available for plants in the year of application due to rapid transformation of applied P to insoluble forms (“fixed” P) with limited plantavailability. The residual effectiveness of applied P fertilizer decline over time due to further transformation of applied P to more insoluble forms. High nutrient loading intended to overcome P availability limitations in high P-f... G. Hettiarachchi |
8. Can Nitrapyrin and Cover Crop Improve Fall Dairy Slurry N Availability to Corn?Fall applications of manure have the potential for high nitrogen (N) losses. Cereal/grass cover crops have been shown to take up fall applied N. Similarly, using nitrapyrin (Instinct®) has been shown to prevent loss of fall applied N. No studies have been conducted to evaluate combining these tools to prevent N loss. This experiment was performed in 2016 and 2017 on a well-drained and somewhat poorly drained silt loam soils. This study was conducted to determine if using Instinct®... A. Teeter, T. Andraski, C. Laboski |
9. 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... |
10. Carbon and Nitrogen Dynamics: Cover Crop Decomposition during the Following Cash Crop Growing SeasonNitrogen (N) loss from agriculture fields in the Corn Belt contributes to impaired waterways and the development of the “Dead Zone” in the Gulf of Mexico. It has been well established that cover crops can scavenge N, which results in a reduction of N loss via tile drainage. However, the literature suggests that increased C inputs from decomposing cover crop residue may result in N immobilization during the following cash crop growing season andnegative yield impacts. Therefore, th... C. Lacey |
11. 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... |
12. 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 |
13. 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... |
14. Corn, Rye, and NitrogenThe U.S. still has an erosion problem. Half of the topsoil is gone over much of the Midwestern U.S., and erosion continues at an unacceptable rate. Protecting soil after soybean is grown is the weakest link in the chain because soybean leaves so little residue that even with no tillage the soil is vulnerable. Cover crops offer great promise to solve this problem. Rye is cheap, hardy, grows well in cool fall weather, and is easy to kill, but evidence continues to mount that rye causes yield lo... P. Scharf |
15. Correlation Between Mehlich-3 and Haney Extractable Phosphorus and Potassium, and Their Relationship to Soybean (Glycine Max) Yield ResponseNumerous soil tests have been developed for estimating the plant-availability of soil phosphorus (P) and potassium (K). Understanding the relationship between these test’s results and crop response to fertilizer application is essential for developing and improving fertilizer recommendations. Field trials have been initiated at six sites located across the state of Kansas to investigate the response of soybean to broadcast P and K fertilizer application. Plots a... E. Rutter, D. Ruiz diaz, F. Hansel |
16. 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 |
17. Cover Crop and Nitrogen Fertilizer Rate Effects on Mitigating Soil Nitrate Leaching in Irrigated Sandy Soils in Corn and Soybean ProductionCoarse textured soils are very productive when supplemented with irrigation and nitrogen (N); however, they are susceptible to nitrate (NO3–N) leaching. Nitrate leaching not only reduces fertilizer efficiency but has costly environmental impacts to the groundwater supply. The majority of NO3–N loss occurs in the fall and spring or when nutrient and water uptake from corn (Zea mays L.) and soybean (Glycine max Merr. L.) is limited but precipitation is fr... N. Ricks, F. Fernandez |
18. Cover Crops Impact on Biomass, Yield, Soil Health, and Nutrient Loss in a Tile-Terrace FieldSoil erosion by water can be the most important land degradation process on erodible to highly erodible soils. Therefore, different conservation practices can be implemented to address the issue including no-tillage, cover crops (CC), grass filter strips, riparian buffers, and terraces. A field trial was established at the University of Missouri Grace Greenley Research Center near Novelty to evaluate the impact of CC and no-CC (non-treated control, NTC) on crop yields, soil health, and water ... R. Adler, G. Singh, K. Nelson |
19. 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... |
20. 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 |
21. 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... |
22. 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... |
23. 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... |
24. 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 ... |
25. Effects of Sampling Time and Extraction Method on Soil-Test and Nonexchangeable Potassium in Iowa SoilsMore research is needed to better understand K cycling and high short-term temporal soil-test K (STK) variation. The objective of this research was to study soil-test K and nonexchangeable K pools across Iowa soils managed with corn-soybean rotations as affected by K application rates, soil properties, parent materials, and time of sampling. Three-year field trials that included a control and several broadcast K fertilizer rates were conducted at 35 Iowa sites. Soil samples (6-inch depth) wer... R. Oltmans, A. Mallarino |
26. Estimation of Nitrogen Losses from Char Amended Fertilized Soils: a Laboratory StudyMore than 50% of nitrogen (N) fertilizer added to agricultural soil is lost to the environment through volatilization, denitrification, and leaching. Proper management of soil carbon (C) may reduce N losses since soil C affects soil properties and N cycling. There are a wide range of soil C management practices, including direct addition of high C content materials to the soil. A 30-day laboratory study was conducted to evaluate effects of char on N losses from fertilized loam and sandy loam ... D. Panday, B. Maharjan |
27. Evaluation of Potassium Fertilization Strategies for Corn and Soybean: the Buildup PhasePotassium is a crop nutrient which can severely limit yield potential when deficient. Potassium fertilizer historically was low cost. Price increases have resulted in more questions as to the benefit from potassium applied for corn and soybean. The objective of this study was establish a set of trials which vary in soil test K level to be used to determine corn and soybean grain yield response to K based on initial soil test and to compare soil K analysis on moist versus air dried soil sample... J. Vetsch, D. Kaiser |
28. Fertilizer Management of Soybean in Northwestern and Northcentral North DakotaSoybean (Glycine max L.) is a new cash crop for northcentral and northwestern North Dakota (ND) producers. Soils and climate in these new soybean areas differ from current fertilizer guidelines. North central and northwestern ND is more undulating, arid, cooler, and has differing soil pH. A three year study to evaluate soybean best management practices was initiated in the spring of 2016 and will be concluded in 2018. Each year had two sites and twelve treatments. One site was acidic (pH... C. Augustin, D. Franzen |
29. Grid Soil Sample Interpolation Using Geographicaly Weighted Regression and Random ForestSoil sampling is useful in agriculture for setting fertilizer application rates. High density soil samples can also be used for variable rate seeding and other precision agriculture applications. Half-acre grid soil samples were collected from 6 soybean fields, and phosphorous (P), potassium (K), and organic matter (OM) were measured. Each soil parameter was interpolated for each field, with terrain attributes as covariates, using two different methods: geographically weighted regression (GWR... E. Matcham, S. Subburayalu, J. Fulton, E. Hawkins, P. Paul, L. Lindsey |
30. How Late Can Nitrogen Be Applied to Corn?Delaying some of the N supplied to the corn crop is considered a way to increase N uptake and yield and to limit N losses, but the length of the delay may increase the risk of yield loss. We conducted a 3-year experiment at Urbana, Illinois in which half of the N (112 kg N/ha) was injected as UAN at planting and the other half or all (224 kg N/ha) of the N was dribbled UAN next to the row, at each of eight stages ranging from V3 to R3. In corn following soybean, when half of the N was applied... B. Yoder |
31. 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... |
32. 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. ... |
33. 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. ... |
34. Iowa's 1987 Groundwater Protection ActThe law is the result of public concern about contamination of Iowa's groundwater resources. Data from all over the state have shown that agricultural chemicals are finding their way into -ter. The law calls for spending $64.5 million over 5 years on programs to prevent groundwater contamination from agricultural chemicals, sinkholes, agricultural drainage wells, municipal and irdustrial wastes, landfills, household chemicals, and buried chemical and petroleum storage tanks. Three fourths of the... |
35. 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 |
36. Nitrogen Availability and Corn Production in Minnesota Following Cover CropsCover crops are often included in BMPs for reducing soil erosion, building soil organic matter, and reducing nitrate leaching. Because of additional management requirement and uncertainties about their impact on nitrogen availability and cash crop yields, cover crops have not been widely adopted in conventional fields. This study aims to reduce these uncertainties for corn growers in Minnesota by measuring the impact of select cover crops on corn yield, nitrogen ... S. Badger |
37. 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... |
38. Nitrogen Management in Minnesota as Influenced by Soil Drainage and TillageTile-draining, conventional tillage and pre-plant applications of nitrogen (N) fertilizer are prevalent practices among Minnesota corn growers. However, climate change and increasingly warmer and wetter spring conditions have called for a re- evaluation of the appropriateness of these practices for continued sustainable corn production. The objectives of this study are to determine the influence of drainage, tillage and N application timing on (1) corn grain yield and N uptake, (2) corn N dem... G. Paiao, F. Fernandez |
39. 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 |
40. Nitrogen Source and Timing Effects on CornThe 4R’s of nutrient management call for the right source, applied at right time, at the right rate at the right placement. Producers in South Dakota ask when the correct time to apply nitrogen fertilizers. Mean annual precipitation in the major South Dakota corn growing areas ranges from 16 to 26 inches. This is a relatively dry climate compared to other major corn growing regions and the effect of nitrogen timing might not be as important. Therefore, a research question that challenge... A. Bly, S. Berg, D. Karki |
41. Nitrogen Timing and Sidedress Placement Strategies in MichiganNitrogen (N) timing and placement methods are key components to improve corn (Zea mays L.) N management. Studies were initiated in Richville and Lansing, MI in 2017 utilizing four N timing strategies including 100% N broadcast after planting (PRE); 50% N pre-plant incorporated with 50% N sidedressed (SD) at V6 (50/50); no pre-plant N with 100% N SD V6 (0/100); and 40 lbs N A-1 applied 2-in below and to the side of the seed (2x2) with remaining N SD V6. The PRE strategy was also appl... T. Purucker, K. Steinke |
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. Not All Litter is Created Equal: Differences in Nitrogen Mineralization Among Broiler Litter TypesOver three fourths of U.S. broiler chicken production is located in the Southeast and generates a substantial amount of broiler litter (BL). Broiler litter is a mixture of bedding material and manure that can be a valuable nutrient source for row crop production when properly used. New technologies provide farmers with the opportunity to use a combination of BL and inorganic fertilizers with minimal environmental impact. The first part of the project evaluated integrated N management systems ... L. Fitzgerald, E. Ritchey, J. Mcgrath, J. Shockley, H. Poffenbarger |
44. 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 ... |
45. Performance of Grain Oats at Different Nitrogen Regimes when Grown with and without Plant Growth Regulator (PGR)Among small grains grown in the South Dakota (SD), oat is considered the most susceptible to lodging which can result to significant yield loss due to harvest difficulty. Although current South Dakota State University (updated 2005) recommends 1.3 pounds nitrate N per bushel of oats (minus soil test N and legume credit), producers have been using lesser than the SD recommended rate to avoid lodging. This study was initiated in 2016- i) to evaluate the response of oat grain yield at various ni... D. Karki, A. Bly |
46. Polyhalite Alters the Uptake and Partitioning of Mineral Nutrients in MaizeModern maize (Zea mays L.) hybrids coupled with advanced agronomic practices have led to an increased yield potential on many US corn acres. To realize these higher yields demands a better understanding of crop nutrition. The objective of this study was to document the pattern of uptake, partitioning, and remobilization of nutrients released after potassium fertilization, specifically muriate of potash (MOP; 0-0-60) and/or polyhalite fertilizers (0-0-14-6Mg-17Ca- ... S. Foxhoven |
47. 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 ... |
48. 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... |
49. Side-dressing Nitrogen Influence on Nitrogen Release Dynamics of Early and Late-Terminated Cereal Cover CropTermination date and nitrogen application of corn (Zea mays L.) can influence the decomposition rate of cover crops in a corn cropping system. Our objective was to evaluate (i) the biomass accumulation and nutrient uptake of wheat (Triticum aestivum L.) fertilized with 34 kg N/ha and (ii) decomposition rate of wheat terminated early (4 weeks prior to planting) and late (at corn planting time) with and without side-dressing N at 168 kg N/ha. Our preliminary d... A. Sadeghpour, G. Singh, A. Weidhuner, R. Lange |
50. Soil Nitrogen Management is Impacted by Soil Texture and WeatherNitrogen (N) is an important nutrient for corn production that is often supplied as inorganic fertilizer, but its use can also lead to environmental degradation. The 4R (right rate, source, time, and placement) approach has been suggested as a framework for N management to improve crop yield and nutrient use efficiency while minimizing environmental contamination. There is not a universal 4R best management strategy, nor should there be because many variables impact N... J. Spackman |
51. Soil Phosphorus Fractions and Legacy after Long-term Fertilizer Placement in a Corn-Soybean RotationPhosphorus (P) fertilizer placement can affect plant P uptake during the growing season, however, the long-term interaction of placement and plant root P uptake can also affect soil P pools. The objective of this study was to evaluate the influence of long-term P fertilizer placement on soil P pools (labile, moderately labile and non-labile) and legacy soil P accumulation under a corn (Zea mays) -soybean (Glycine max (L.) Merr.) rotation. A field study was conducted for ten years from 20... M. Coelho, D. Ruiz diaz, G. Hettiarachchi, F. Hansel |
52. Soil Properties and Corn Yield as Effected by 70 year of Cattle Manure ApplicationLong-term experiments provide valuable information about the environment x agronomy interaction impacts on soil and crop productivity. The irrigated Knorr-Holden experimental site near Mitchell, Nebraska was established in 1912 and had a non- replicated unfertilized maize plot until 1941. In 1942 the plot was split into two manure treatments (0 and 27 Mg ha-1 yr-1 cattle manure) with 0.04 ha each. In 1953, second replication was added using adjacent land. The same year, manure treat... B. Maharjan |
53. Soybean Response to Potassium Fertility and Fertilizer in ManitobaSoybean acres have increased greatly in Manitoba in recent years, now occupying more than 25% of the province’s annual crop land. Potassium removal by soybean is greater than any other crop grown in Manitoba (1.1 – 1.4 lb K2O/bu). This large removal, accompanied by the large and rapid expansion in soybean acres, has contributed to an increase in province-wide potassium removal rates and likely explains the increase in incidence of potassium deficiency symptoms reported in recent y... M. Bourns, D. Flaten, J. Heard, G. Bartley |
54. Sulfur Fertility for Kentucky Agriculture: An UpdateSulfur (S) is an essential secondary nutrient for plant growth and is involved with the synthesis of chlorophyll, hormones, and a structural component of proteins. The need for supplemental S fertilizer in Kentucky has been questioned for many years due to lower atmospheric S deposition, fewer fertilizer impurities, soil test laboratory recommendations, and greater crop yields, but field research has not supported this concern. Recent tissue surveys in wheat and alfalfa across ... E. Ritchey, J. Gray |
55. 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 ... |
56. Use and Misuse of Aerial ImageryThroughout the 1990’s agricultural researchers were hitting the sky’s collecting untold amounts of spectral data. The majority of that push quieted down in the early 2000’s as scalability was a constant struggle. However, in the past few years the introduction of affordable and easy to use unmanned aerial vehicles (UAV), more cost effective cameras, and significant increase in satellite constellations has reignited the interest in remote sensing that died out a dec... B. Arnall |
57. 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... |
58. 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... |