Ahmed M. Saad, Marwa G. Mohamed and Gamal A. El-Sanat
AquaCrop model (version 4) was validated using data from two field experiments conducted at North Delta (Sakha and El-Hamoul Districts) during the summer seasons of 2012 and 2013. Maize cross 321 variety was sown to study the effect of deficit irrigation, nitrogen fertilization and soil mulching on maize water productivity. After that, AquaCrop model was validated using such data by different statistical indicators such as coefficient of determination( R2),normalized root mean square error ( NRMSE),degree of agreement (D )and efficiency (E). Results indicated that, AquaCrop software was able to simulate well maize water productivity under different irrigation regimes, nitrogen fertilization levels and mulching application at North Delta. Where, under non saline soil conditions (Sakha location) values of R2, NRMSE, D and E were 0.88, 0.36, 0.98 and 0.99 % respectively. While, under saline soil conditions ( El-Hamoul location) values were 0.88, 15.5, 0.12 and 0.77 % for R2, NRMSE, D and E respectively. Data also, showed that, under non saline soil, the highest value of water productivity was obtained by irrigation at 36 days after post planting irrigation ,then irrigation at 70 % depletion from soil available water, non limiting nitrogen fertilization and adding plastic mulching. While, under saline soil conditions, irrigation at 26 days after post planting irrigation, then irrigation at 50 % depletion from soil available water, near optimal nitrogen fertilization and plastic mulching gave the best value of water productivity
