Evaluation of Aquacrop Model in Predicting Wheat Yield and Water Productivity Under Irrigated Saline Regimes

Crop models assist in generating crop productivity trends under future climate and different irrigation water supply scenarios. In this study, the AquaCrop model with a salinity module to simulate the grain yield and water productivity of four wheat varieties, including three salt‐ tolerant (i.e. KRL‐19, KRL‐1‐4, KRL‐210) and one salt non‐tolerant variety (i.e. HD‐2894) grown under different salinity levels was evaluated. The experiment was conducted at the research farm of the Water Technology Centre (WTC), Indian Agricultural Research Institute (IARI), New Delhi, during rabi 2009–10 and 2010–11. The model was calibrated using experiment data of rabi 2009–10 and validated with data of rabi 2010–11. Saline water of 4, 8 and 12 dS m−1 and groundwater (i.e. 1.5 dS m−1 during rabi 2009–10 and 1.7 dS m−1 during rabi 2010–11) were used for irrigation. The validated model prediction error statistics, i.e. model efficiency (ME), index of agreement (d) and coefficient of determination (R2) for grain yield, were 0.85, 0.96, 0.94 and for biomass 0.7, 0.95, 0.95, respectively, for all varieties and salinity levels. It was observed that the AquaCrop model was better at predicting the grain yield compared to biomass and water productivity for all varieties and salinity levels.