Assessing Aquacrop Model Accuracy for Simulation of Corn Yield and Water Use Efficiency in Different Plant Densities and Water Amount

The importance of the corn plant has led to the widespread cultivation of different cultivars of this crop in many parts of Iran. Since the study of environmental and managerial factors such as planting density, irrigation amount and plant cultivar on grain yield, biomass and water use efficiency of crops requires costly and time-consuming field experiments, it seems that the effect of various factors on the crop yield can be stimulated using plant models. The present study was performed to evaluate the AquaCrop plant model for two maize cultivars, mid cultivar SC500 and early cultivar SC302, under 75000, 85000 and 95000 and 80000, 90000 and 100000 plant/ha densities, respectively, with different irrigation values of 75, 100 and 125%. The results showed that the AquaCrop model had good accuracy (RSME = 0.89 ton/ha and NRSME = 0.10) in simulating grain yield and maize water use efficiency (EF and d = 0.99). In simulation of corn biomass, this plant model had acceptable accuracy (RSME = 2.47 ton/haand NRSME: = 0.14) and good performance (EF = 0.98 and d = 0.99). AquaCrop model also had good accuracy (RSME = 0.07 kg/m3 and NRSME = 0.07) and efficiency (EF and d = 0.99) in simulating corn water use efficiency. Based on these results, the AquaCrop model is proposed to simulate corn cultivars under the mentioned conditions..