Fig. 2. Comparison between the model-predicted and field-measured soil profile (180-cm) water storage: (a) calibration results for the 200 kg N ha^–1 yr^–1 treatment (WC200N) during 2001 to 2003; (b) validation results for 400, 600, and 800 kg N ha^–1 yr^–1 (WC400N, WC600N, and WC800N, respectively) during 2001 to 2003. Numbers in parentheses are corresponding root mean squared errors.