| Nitrogen and plant population are significant factors for corn (Zea mays L.) production. Accurate nitrogen fertilizer and seeding rate recommendations are essential for optimizing profitability for the farmer and minimizing nitrogen losses. This study examines the relationship of nitrogen and plant population and potential interactions on corn production at two sites in eastern South Dakota. Using standard deviation as a measure of plant spacing uniformity, higher seeding rates correlated to lower standard deviations and vice versa. Higher plant populations also showed higher values for leaf area index, a measurement of plant canopy cover. Nitrogen, but not plant population impacted chlorophyll meter readings. Nitrogen and plant population were found to significantly impact yield, stover, biomass, and harvest index and various sites, but not across all site years. Lower yield potential decreased the significance of nitrogen and plant population on corn production. Economic analysis of each site year indicates seeding rates near 70,000 plants/ha (28,350 seeds/ac) produced optimum yields. Optimum nitrogen rates varied from 0 N/ha to 168 kg N/ha (150 lb N/ac) across all site years. |
