Yield Gap Analysis under Different Water and Nitrogen Management Practices in Wheat Crop using CSM-CROPSIM-CERES –Wheat Model in Tarai Region of Uttarakhand

Abstract

Water and nitrogen are two primary limiting factors for wheat yield. In consonance with this, field experiment was conducted at Norman Ernest Borlaug Crop Research Centre in Pantnagar (Uttarakhand) during Rabi season of 2017-18 to analyze the performance of CSM-CROPSIM-CERES-wheat model for wheat cultivar (PBW-502) grown under different stress conditions characterized by inducing different water and nitrogen levels. 27 treatment combinations consisted of 3 DOS (12 th December, 22 nd December and 02 nd January), 3 irrigation levels (100% irrigations, 75% irrigations and 50% irrigations) and 3 nitrogen levels (100%, 75% and 50% of recommended nitrogen doses) laid in a Factorial RBD with 3 replications. The results revealed good agreement between simulated and measured data of crop phenology, LAI and grain yield. The simulated and observed yield ranged between 1.5 to 4.95 t/ha and 1.42 to 4.73 t/ha, respectively. RMSE was found to be 11.61% with R 2 value of 0.90, which is found significant. The model performance was validated with the experimental dataset of year 2007-2008 by using genetic coefficients obtained during calibration process. Degree of stress in wheat crop was analyzed in terms of yield gap, which was found higher (68. 28 %) under lowest levels of irrigation (2 irrigation) and nitrogen (75 kg ha -1 ).