Impact of climate change on water requirements of wheat and potato in Eastern India

With the objective of investigating the impact of future climate (2020-2095) on the crop water demand of some principal rabi crops, viz, wheat, potato in eastern India, weather data were generated from MarkSim (R) GCM ensemble using three suitable GCMs and at two RCP levels, viz, RCP 4.5 and RCP 8.5. Seasonal potential evapotranspiration (SPET) was estimated using Hargreaves-Samani method, which were subsequently multiplied with crop coefficient to obtain seasonal water requirement (SWR). Decadal changes of SWR were found to be statistically significant for all agroclimatic zones, study crops as well as for all sowing periods. Among the agroclimatic zones, New Alluvial Zone (NAZ) will have maximum SWR across all crops over the 21st century followed by Red Laterite Zone (RLZ) and Terai Zone (TZ). SWR for all crops and agroclimatic zones showed uniform increasing trend over the period 2020-2095.