Proceedings
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| Filter results7 paper(s) found. |
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1. Remote Sensing of Corn Canopy Dynamics and Biophysical Variables Estimation in MichiganThis study was initiated to evaluate sensor-based nitrogen and water application for corn (Zea mays L.) in Michigan. The specific objectives of this study were: 1) to identi@ wavelengths that are more sensitive to N deficiency in corn, 2) to determine when to predict corn grain yield fiom spectral remote sensing data, and 3) to estimate biophysical variables ofcorn such as leafareaindex (LAI) and fractional cover (Fc) fiom spectral vegetation indices (SVI) obtained fiom radiometric measurements over... |
2. Relationship Between Response Indices Measured In-Season and at Harvest in Winter WheatCurrent methods for making nitrogen recommendations in winter wheat (Triticum aestivurn L.) do not adjust for in-season temporal variability of plant available non-fertilizer nitrogen (N) sources. The purpose of this study was to compare the use of different nitrogen response indices determined in-season @INDVI and RIPLANTHEIGkm) to the nitrogen response index measured at harvest (RIHARvEST). In addition, this study evaluated the use of the in-season response indices for determining topdress nitrogen... |
3. The Analysis of Nitrogen and Plant Population InteractionsNitrogen and plant population are significant factors for corn production. Accurate nitrogen fertilizer and seeding rate recommendations are essential for optimizing profitability for the fmer and minimizing nitrogen losses. Research and development of yield response curves provide important information that can be used to understand the relationships between these inputs (nitrogen fertilizer and corn seeds) and output (grain yield). Over the varying levels of inputs. yield response functions can... |
4. Cropping Systems Management Effects on Soil N Mineralization DynamicsChanges in soil organic matter (SOM) content due to cultivation also impacts the amount of indigenous soil nitrogen (IN) supply. Crop management practices designed to achieve high yields also result in high residue inputs, which can contribute to SOM build up and enhanced indigenous N supply. The objective of this study was to evaluate the long term effect of crop rotation and nutrient management in conventional and intensive maize based systems on the change in soil N supply. Soil samples fiotn... |
5. 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... |
6. 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... |
7. Adapt-N: A Computational Tool for Precise N Management in CornCurrent approaches to estimation of optimum N fertilizer rates are based on mass balances, average expected economic return based on field experiments, soil N tests, an d crop leaf or canopy sensing. However, denitrification and leaching losses of nitrogen may occur from dynamic and complex interactions among weather, soil hydrology, crop water and N uptake, and management practices , and result in high variability in annual crop N needs in maize ( Zea mays L.) production. W eather impacts the soil... |