Modelling Wheat Productivity under Deficit Irrigation

Abstract

This research was carried out to simulate wheat growth under deficit irrigation across two cropping years (2020-21 and 2021-22) at Prayagraj, Uttar Pradesh India. Crop growth simulation models are useful for evaluating the impact of water scarcity on crop productivity and crop yield. The AquaCrop model is one of these available options and this model is capable of simulating water productivity, grain yield, biomass yield, and canopy cover. Major inputs for the model in this investigation are climate, soil characteristics, plant attributes, and the management of crop cultivation. The results of the simulation revealed that the model accurately simulates grain yield, water productivity, biomass yield, and canopy cover at different amount of irrigation. The simulated and observed grain yield coefficients of determination (R2) were 0.96 and 0.95, respectively. The model simulation performed well (RMSE=0.131, NRMSE=3.75) and model efficiency (EF) was 0.99. Simulated and observed water productivity is equivalent at different amount of irrigation regimes. The model simulation performed well (RMSE=0.106 and NRMSE=5.00). Simulated and observed water productivity had EF of 0.99 and R2 of 0.96. The model simulation of biomass under different amount of irrigation varied between RMSE ranged from 0.492 to 0.857, NRMSE ranged from 9.239 to 17.513 and EF ranged from 0.97 to 0.99. Coefficients of determination (R2) of simulated biomass yield and observed biomass of all treatments were 0.99. It was determined that the simulated canopy cover for all treatments at different amount of irrigation had successfully adapted to the observed canopy cover. Thus, the RMSE varied from 13.344 to 18.974, the NRMSE from 20.770 to 33.223, and the EF from 0.91 to 0.96 for model simulations treated to various interventions. Coefficients of determination (R2) of simulated canopy cover for all treatments were 0.97, although R2 of observed canopy cover for various treatments ranged from 0.88 to 0.92.