Proceedings
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| Filter results5 paper(s) found. |
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1. Soybean Response to Nitrogen ApplicationsSoybean yield increases due to N fertilizer have been reported recently, particularly for N applications during the reproductive stages. It is also known that nitrate inhibits nodulat ion and nodule activity and could potentially reduce yield. Our objective was to evaluate the effect of N fertilizer on soybean yield. Forty-six experiments were conducted with N fertilizer applied at times ranging fiom planting to late reproductive stages. Some experiments had significant positive or negative responses... |
2. Site-Specific Nitrogen Management for Reducing Soil Residual NitrateSite-specific N management has potential for increasing the efficiency of N fertilizer use, and thereby reducing environmental impact. Field studies were conducted in 2000 and 2001 to evaluate the potential for site-specific N management to reduce residual soil nitrate in Missouri cornfields. Field-size side-by-side fertilizer N treatment strips were applied in cooperating farmers' fields. The site-specific crop N requirement (optimal N rate) was determined for sub- blocks that contained a full... |
3. 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. ... |
4. Biochar: Waste, or Product?Nutrient losses following summer and fall manure applications result in economic and water quality problems. We tested the potential of biochar (BC) and ammonium thiosulphate (ATS) as manure additives to retain nutrients by reduci ng nitrate pool size and runoff of N and P. To determine appropriate rates to use in field expe riments, the compounds were initially added at different rates to liquid swine manure (LSM) then the slurry mixed with soil and incubated. The selected rates, based on N transformations,... |
5. Active and Passive Spectral Sensing for Predicting the Optimum Nitrogen Rate and Timing in CornThere are many in-season plant diagnostic tools available for predicting the rate and timing of in-season nitrogen fertilizer in corn (Zea mays L.). However, soils in Southern Minnesota are generally high in organic matter and can carry over nitrate- nitrogen from one season to the next. Subsequently, there is oftentimes sufficient soil nitrogen early in the growing season to supply much of the crop requirement, limiting the use of sensor-based N management tools. Past work... T. Nigon, D. Kaiser, C. Yang, D. Mulla |