1. 15Nitrogen Uptake and Use Efficiency in Corn in Response to Fertilizer Rate and Timing

Urea fertilizer applications at planting are becoming increasingly common for U.S. upper Midwest corn (Zea mays L.) production but wet spring conditions may result in significant nitrogen (N) fertilizer loss. Split-applications may avoid wet conditions and improve fertilizer uptake and use efficiency. Six field studies were performed to determine the effect of urea fertilizer rate and application timing on fertilizer-derived N (FDN) and soil-derived N (SDN) plant uptake over two consecutive... F. Fernandez, J. Spackman