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| Filter results9 paper(s) found. |
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1. Post-Harvest Soil Nitrate Following Corn Production in Eight Midwestern StatesApplying nitrogen (N) at economically optimal rates (EONR) and at times of rapid crop uptake are practices that are thought to minimize the amount of residual soil nitrate (RSN) in the profile that may be susceptible to loss. The objective of this study was to evaluate the effects of rate (0 to 280 lb N/a in 40 lb increments) and timing (pre-plant (PP) or PP plus V9 sidedress (PP+SD)) of N application on corn grain yield and RSN in the top 3 feet of soil relative to the calculated EONR. Thirty-two... C. Bandura, C. Laboski, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, E. Nafziger, J. Sawyer, J. Shanahan |
2. Variation in Internal N Efficiency of Corn and Impact on Yield-Goal Based N RecommendationsInternal N efficiency (IE) is defined as bushels per acre (GY) produced per pound of N per acre (PMN) in the plant at physiological maturity (R6). Internal N efficiency defines the required amount of plant N content at R6 in a yield-goal based N rate recommendations (currently used in 30 U.S. states) and several commercial N recommendation models. Commonly IE is assumed to be constant at an approximate value of 0.8 bu lb-N-1 in yield-goal based recommendations. Our research objective was... M. Shafer, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, R. Nielsen, J. Sawyer, J. Shanahan |
3. Residue Harvest Effect on Irrigated, No-till Corn Yield and Nitrogen ResponseImmobilization of applied N is expected when much high C:N crop residue remains in the field as is typical following corn grain harvest. Immobilization of N is expected to be less if crop residue is less. The effect of reduced immobilization on N availability may more than compensate for N removed in residue harvest. Therefore, applied N requirement for a following corn crop may be less if crop residue is reduced through harvest. Residue removal decreased the economically optimal N rate (EONR) by... |
4. Assessing the Benefits of Radish as a Cover CropOilseed radish (Raphanus sativus L) is a popular cover crop for no-till farmers in Wisconsin, especially among those that include winter wheat in rotation since radish can accumulate large amounts of nitrogen (N). However, previously presented research in Wisconsin has not shown a clear N credit for a subsequent corn crop. Additionally, there is a lack of information that quantifies other benefits of radish, including compaction reduction and nematode suppression. The objective of this project was... |
5. Active Sensor Orientation Over Corn Rows and Effect on Assessment of BiomassOur long-tern mresearch goal is to develop practical N application systems that use on-the-go remote sensing as a nleans to assess crop N status and only apply N where needed at times when the crop can most efficiently utilize N. Our preliminaty testing of two active sensor systems has shoxl-11 considerable promise for rapid and accurate assessment of canopy N status and crop biomass. In this work, the effect of sensor positioning and orientation over the canopy and their effects on assessment of... |
6. In Season RecommendationsWe are testing a prototype high-clearance tractor configured with active crop canopy sensors, drop nozzles with electronic valves, and a variable rate controller as means to deliver in-season variable rates of liquid N fertilizer based on crop needs as an alterative to preplant uniform applications of N. The active sensor we're evaluating is the model ACS-210 Crop Circle made by Holland Scientific. It generates it's own source of modulated light in the amber and near infrared (NIR) bands and then... |
7. Organic Farming in Nebraska: Establishing Organic Research for the Organic Farming CommunityFour sites in Nebraska were developed to have land available to conduct research on certified organic land. All sites will be certified organic by the end of 2008. The goal of the project is to conduct research relevant to the organic farmi ng community and not to compare organic systems with conventional systems. Resear ch is being conducted on the use of flaming to control weeds, winter wheat variety development and selection for the organic market, variety testing of organic winter wheat, proso... |
8. 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 procedure... |
9. Stover Removal Effects on Continuous Corn Yield and Nitrogen Use Efficiency Under IrrigationCorn (Zea mays L.) residue or stover is harvested as supplemental feed for livestock and is a primary feedstock for cellulosic biofuels. Limited information is available on corn residue removal effects on grain yield under different nitrogen (N) fertilizer rates, irrigation rates and amelioration practices to minimize soil carbon loss and soil erosion. A study on a silt loam in south, central Nebraska (2011-2016) evaluated potential interactions between stover removal (residue removal,... M. Schmer, V. Jin, A. Sindelar, R. Ferguson, B. Wienhold |