Evaluating AquaCrop Model Performance to Predict Grain Yield and Wheat Biomass, Under Water Stress

This study was conducted for evaluating AquaCrop model performance in prediction of grain yield and biomass production of winter wheat, under water stress at Fars Agricultural Research Station (Zarghan), during two years (2006-2008). The experiment was a randomized block, based on a split plot design with four replications. Main plots consisted of two irrigation treatments, namely I1 (nonstressed), and I2 (Post anthesis water stressed plots with 65% FC). Each subplot consisted of three varieties; Shiraz, Marvdasht, and Chamran. Evaluation of the simulated yield and biomass production values were performed based on the measured data adjusted coefficient of correlation, relative error, and normalized root mean square error (NRMSE). Based on the results, the NRMSE values for the predicted grain yield of studied varieties in the calibration and validation stages were between of 0.5-2, and 2-9 percent, respectively. Also, the NRMSE values of calibration and validation in biomass production for the varieties, were between 2-5, and 3-6 percent, respectively. Results indicated that the AquaCrop model could predict the grain yield and biomass production with an acceptable accuracy.