Proceedings
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| Filter results6 paper(s) found. |
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1. 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 preplant,... |
2. 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. In... |
3. 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 relies... |
4. Nitrogen Fertilizer and Irrigation Effects on Soil and Plant Nitrogen DynamicsCropping systems can be exposed to different nitrogen (N) and water availabilities for a variety of reasons. Both N and water have been shown to have both positive and negative; direct and indirect effects on soil and plant N dynamics. Given that agronomic crops require large amounts of N to achieve high yields and often acquire a majority of their N from soil nitrogen mineralization (N min), it is important to understand how nitrogen and water interactions alter soil and plant N dynamics. Our... T. Donovan, J. Schneekloth, L. Comas, M. Schipanski |
5. Developing a Sustainable Sufficiency ParadigmSustainable conservation practices must align agronomic productivity and environmental protection goals to facilitate widespread and consistent adoption on-farm. Agricultural phosphorus (P) management is a critical control point for detrimental environmental consequences of P loss in surface runoff from agricultural fields. Reduced P fertilizer inputs are recognized as an effective and necessary control measure to limit P loss; however, current P fertilizer recommendation systems do not support... M.A. Bourns, N.O. Nelson, D. Ruiz diaz, G. Roa |
6. Effects of Cover Crops on Surface Runoff Under Increasing Precipitation IntensitiesWith climate change increasing the frequency of extreme precipitation events, the risks of erosion, nutrient transport and flooding increase as well. Cover crops (CC) are a best management practice for cropping systems that are vulnerable to soil erosion. The objective was to analyze the effects of CC and precipitation intensity on surface runoff and water quality under natural precipitation events. Runoff and water quality data were collected from 2015-2022 from a corn-soybean cropping... S. Moylan, N.O. Nelson, G. Kluitenberg, A. Sheshukov |