Corn Yield Response to Nitrogen at Multiple In-Field Locations

摘要: Improving N management for corn (Zea mays L.) production with precision agriculture technologies requires that spatial recommendations adequately represent in-field variability in availability. Our objective was to evaluate response increasing rates several locations represented the range of soil organic matter (OM) content field. In a 2-yr study, three center pivot-irrigated fields were selected south-central Kansas and Nebraska. Four or five within each At location, six treatments (0-336 kg ha -1 ) surface-applied early growing season. The minimum rate achieve maximum yield varied by as much 130 among at site-years. least amount did not coincide representing greater OM. Yield two site-years same locations; however, mean 4.2 Mg , potential improvement use efficiency. Leaf tissue below critical threshold 60 100% observations different but <35% all other locations. reason discrepancy availability conclusively identified only related OM content. Variable based on is too simplistic reflect