Impacts of climate change on phenology, yield, and water productivity of wheat in a semi-arid region of India using the CERES-Wheat model

In the present study, the Crop Environment Resource Synthesis (CERES)-Wheat model was used to study the impacts of climate change on phenology, yield, and water productivity of wheat. The model was run with the baseline period (1980-2010) and three future periods, namely, the 2030s, 2050s, and 2070s under two representative concentration pathway (RCP) scenarios, namely, RCP 4.5 and RCP 8.5. The results indicated a substantial decline in phenology, grain yield, biomass, and crop water productivity (CWP) under both scenarios. The grain yield of wheat showed a decline by 12.3, 20.5, and 19.8% during the 2030s, 2050s, and 2070s, respectively, under RCP 4.5 at baseline CO2 concentration, while at elevated concentration of CO2, the reduction was 10.2, 15.7, and 14.9%, respectively. Under RCP 8.5, the yield reduction was 18.8, 26.5, and 27.3% during the 2030s, 2050s, and 2070s, respectively, with baseline concentration of CO2, while with increased CO2 the yield reduction was 7, 12.6, and 8.9%, respectively. CWP decreased at baseline CO2 by 9, 17.6, and 18.3% for RCP 4.5 and 10.6, 20.6, and 22.6% for RCP 8.5 during the 2030s, 2050s, and 2070s, respectively. However, beneficial impact of CO2 fertilization on CWP was noticed in both RCP scenarios, resulting in relatively less reduction under future CO2 concentration.