simulating spring wheat growth under simultaneous salinity and water stress using the aquacrop model

Crop growth simulation models are developed to predict the effects of different factors, including water and salinity on grain, biomass yields, and water efficiency of various crops. these models are typically calibrated and validated for specific regions based on the availability of measured field data. in this research, spring wheat growth under simultaneous salinity and water stress was simulated using the aquacrop model. calibration and validation were conducted using data from 2010 and 2011, respectively. results indicate that aquacrop accurately simulated spring wheat yield, biomass, water use efficiency, and harvest index under salinity and water-limiting conditions. the simulation of harvest index and soil salinity profiles was less precise compared to other characteristics. the mean values of nrmse, me, d, crm, and r2 for grain yield were 13.3%, 36.1%, 0.95, -0.072, and 0.87, respectively in both calibration and verification. for biomass, these measures were 12.59%, 34.46%, 0.92, 0.057, and 0.77, separately. the corresponding values for the soil moisture profile were 11.84%, 25.72%, 0.93, and 0.032, while for the soil salinity profile, they were 26.25%, 58.5%, 0.91, and -0.12, respectively. the most sensitive parameters included the crop transpiration coefficient, normalized crop water productivity, reference harvest index, volumetric water content at field capacity, soil water content at saturation, and temperature.