Fig. 4. Soil water filled pore space (WFPS) and rainfall (continuous bars) plus irrigation (dashed bars) during 1998–1999 growing season in no-tillage maize. P repesents urea applied at planting; V6 represents urea applied at the six-leaf stage (V6). 0–N is the control; 70 and 210 is kg N ha^-1; F represents flowering; PM represents physiological maturity.