Abstract:
Wheat crop is one of the most significant crops in Pakistan to fulfill food requirements, however slight change in temperature and precipitation pattern can change reduce the yield and cropping pattern of the wheat crop. Moreover, according to International Monetary fund (IMF), Pakistan is third among the nation facing severe water shortage, which if not catered properly, will severely affect the agriculture of the country. Therefore, the objective of the study was to calibrate and validate well known DSSAT crop model for wheat yield and crop water productivity and evaluate the impact of climate change on wheat and crop water productivity under changing climate projections using CORDEX-SA-RCMs data for RCP4.5 and 8.5. Furthermore, the wheat crop model was calibrated and validated for crop phenology including (Biomass, yield and Leaf area index) and two cultivars namely (Faisalabad-2008 and Sehar-2006). The experiment data at different nitrogen level was obtained from Ayub Agriculture Research Institute, Faisalabad. After calibration and validation of the model present climate data was replaced with the CORDEX-SA RCM-projections for climate change impact analysis. A significant rise and declining tendencies were observed in temperature and precipitation patterns, respectively, for particular study area. Therefore, substantial impact of climate change on wheat phenology (anthesis day, maturity day) growing degree days, biomass (kg/ha), yield (kg/ha) and crop water productivity (kg/ha) was observed under scenario periods for RCP4.5 and 8.5 at different nitrogen levels. Generally, it was detected that changes in crop phenology had a stronger impact in terms of crop yield for RCP4.5 and far drastic in RCP8.5 and this change in yield also indicates that decline in crop water productivity under both RCP4.5 and 8.5.
