Fig. 1. Denitrification N losses in no-tillage irrigated maize as a function of N rates and application times in the 1996–1997 and 1998–1999 growing seasons. 0–N is the control; 70, and 210 is kg N ha^-1; P is fertilization at planting; V6 is fertilization at the six-leaf stage; F is flowering; PM is physiological maturity. Asterisks indicate significant effect (P 0.05) of the N rate on denitrification rates log-transformed.