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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. 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... |
3. 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... |
4. 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 ... |
5. 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... |
6. 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 ... |
7. 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 ... |
8. 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... |
9. 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... |
10. 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... |
11. 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... |
12. 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... |
13. 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... |
14. 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... |
15. 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... |
16. 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... |
17. 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... |
18. 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 ... |
19. 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... |
20. 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... |
21. 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 ... |
22. 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 ... |
23. 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... |
24. 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... |
25. 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... |
26. 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 ... |
27. 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... |
28. 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... |