Performance evaluation of AquaCrop model to predict yield production of wheat, soil water and solute transport under water and salinity stresses

In this study, the performance of AquaCrop model to predict yield production of winter wheat (Roshan and Gods varieties), water and solute balance of soil profile was evaluated under water and salinity stresses. Field experiments were conducted with three levels of saline irrigation water including: S1, S2 and S3corresponding to 1.4, 4.5 and 9.6 dS/m, respectively, and four levels of irrigation depth including: I1, I2, I3 and I4 corresponding to 50, 75, 100 and 125 percent of crop water requirement, respectively, with three replications in Birjand region for 2005-2006 period. The AquaCrop model predicted the grain yield with a high precision in both of the varieties. The mean relative error of the model calibration for grain yield prediction of Roshan and Ghods were calculated 2.98 and 4.82 percent, respectively. The average normalized root mean square error of calibration and validation in soil water content prediction for Roshan variety, were calculated 14.58 and 15.1 percent, respectively, and Ghods variety, were calculated 14.6 and 15.3 percent, respectively. The average normalized root mean square error of calibration and validation in ECe prediction for Roshan variety, were calculated 34.6 and 36.8 percent, respectively, and Ghods variety, were calculated 34.5 and 36.8 percent, respectively. Results indicated that the AquaCrop predicted ECe with more error compared with soil water content and grain yield.