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1. 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 ... |
2. 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 ... |
3. 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... |
4. 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... |
5. 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... |
6. 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... |
7. 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 ... |
8. 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... |
9. 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 ... |
10. 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 ... |
11. 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... |
12. 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... |
13. 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... |
14. 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... |
15. 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... |
16. 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... |
17. 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... |
18. 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 ... |
19. 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... |
20. 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... |
21. 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... |
22. 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. ... |
23. 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. ... |
24. 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... |
25. 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... |
26. 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... |
27. 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... |
28. 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 ... |
29. 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... |
30. 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... |
31. 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... |
32. 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... |
33. 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 ... |
34. 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... |
35. 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... |
36. 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 ... |
37. 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... |
38. 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... |
39. 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 ... |
40. 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 ... |
41. 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 ... |
42. 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... |
43. 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... |
44. 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... |
45. 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 ... |
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. 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... |
49. 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... |