Development and Evaluation of Irrigation Management Strategies for Higher Yield and Water Productivity of Wheat: A Simulation Modelling Approach

Abstract

: In the present study, CERES-wheat model was calibrated and validated for predicting growth and yield of wheat by using three years of experimental data (2016-17, 2017-18 and 2019-20) under different irrigation treatments. Further the model was run with twenty years of weather data (2000-01 to 2019-20) with optimum management practices under different irrigation scenarios for developing the irrigation management strategies for obtaining higher grain yield and irrigation water productivity (IWP) under dry, wet and normal rainfall conditions. The results indicated that the model slightly overestimated the maximum leaf area index (LAI) and consequently the grain yield in water stress condition; however, overall, model could excellently simulate anthesis and maturity with RMSE<4 days, RMSEn<10% and d>0.90, as well as grain yield (RMSE= 163-204 kg/ha, RMSEn =3-6%, d = 0.93-0.98) for three, four and five irrigations from CRI to jointing, CRI to anthesis and CRI to dough stage, respectively. The IWP was increased with the decrease in number of irrigations. The maximum yield was obtained when the four irrigations applied from CRI to Anthesis under all-weather years (Dry, wet and normal), but it was as par with the three irrigations applied at CRI, Tillering and Jointing or CRI, Tillering and Anthesis stage for wet years. Under three irrigations scenario the maximum yield of 5050-5302 kg/ha and irrigation water productivity (IWP) of 33.7-35.3 kg/ha-mm was noticed when three irrigations applied at CRI, Tillering and Jointing followed by at CRI, Tillering, Anthesis stage and CRI, Jointing and Anthesis stage and under wet year no difference was noticed in yield and IWP whether three irrigations were applied at CRI, Tillering and Jointing or CRI, Tillering and Anthesis stage and under two irrigations scenario, the maximum grain yield as well as IWP was obtained when applied at CRI and Tillering followed by CRI and Jointing stage.