Evaluation of the AquaCrop model to simulation of the potato growth and yield under water stress

Crop simulation models are valuable tools for quantifying crop yield response to water, and for devising strategies to improve agricultural water management. In this study, AquaCrop model was evaluated for simulation of potato biomass, yield and water use efficiency under different irrigation levels. To model evaluation was used from fields results of years 2013 and 2014 at research station of the SHahrekord CHahartakhteh. Field experiments included three irrigation levels; full irrigation (FI), 80% of the water requirement (I80) and 65% water requirement (I65). The model was calibrated and validated using data of the first and second years, respectively. NRMSE index was obtained for yield and biomass in FI, I80 and I65 treatments; 8.5 and 9.58, 18.16 and 14.42 and 30.59 and 25.08 percent, respectively. Was calculated R2 coefficient to compare of yield and biomass in validation step between 0.92 to 0.99, which showed the model accuracy for simulation. The model precision was the level lowest in I65 so that the index of agreement (d) was determined for biomass and yield 0.79 and 0.91 , respectively. The difference percentage of between measured and simulated water use efficiency for treatments FI, I80 and I65 was calculated 9.2, 11.8 and 15.1. In the end, the results showed that the model has less accuracy in I65 treatments.