Proceedings
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| Filter results15 paper(s) found. |
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1. 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 produces... |
2. 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 chlorinating... |
3. 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... |
4. 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 test... |
5. 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. ... |
6. 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 considered.... |
7. 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 within... |
8. 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 cost... |
9. 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 demonstrations... |
10. 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 included... |
11. Understanding Spatial Variability in Cover Crop Growth and DecompositionIn many agricultural landscapes, topographic variability leads to downslope movement of soil, water, and nutrients, causing heterogeneity in both crop yield and soil fertility throughout production fields. Cover crops can slow these processes, but the impact of topography on cover crop growth and residue persistence is uncertain. We measured the growth, mixture biomass composition, and decomposition of a cereal rye (Secale cereale L.) cover crop, and cereal rye /crimson clover (Trifolium... S.J. Leuthold, M. Salmeron, O. Wendroth, E. Haramoto, H. Poffenbarger |
12. 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 values... E. Ritchey, E. Haramoto, C. Bradley |
13. Nitrogen Use Efficiency and Corn Yield as Affected by Applied Sulfur and Nitrogen FertilizerOverall corn (Zea mays L.) yield response, as well as nitrogen uptake and nitrogen use efficiency, can be affected by multiple factors, including the supply of other nutrients such as sulfur. The objective of this study was to evaluate the effect of nitrogen with added sulfur fertilizer on corn response parameters i) whole plant nitrogen uptake, ii) yield, and iii) nitrogen use efficiency when compared to nitrogen alone. Nitrogen Use Efficiencies evaluated in this study included i) Apparent... T. Husa, D. Ruiz diaz |
14. 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 1)... K. Steinke, Z. Hayden, M. Suplito |
15. Influence of Soil Amendments and Topographic Position on Winter Wheat Heavy Metal UptakeField crop heavy metal accumulation poses a major challenge for reducing food contamination and is governed by complex interactions between soil physical and chemical properties, climatic conditions, and intrinsic plant traits. Addressing these challenges requires an understanding of heavy metal accumulation during crop development and effective pre-harvest field mitigation strategies. Two winter wheat (Triticum aestivum L.) field studies were conducted in Michigan focusing on 1) fertilizer... K. Steinke, M. Suplito, Z. Hayden |