Consumptive water footprint of rice for diverse water managements using APSIM under climate change

Water resources for agriculture are under severe threat in India. Crop yield and productivity are going to be affected in the future because of climate change. Hence, it is essential to assess the impact of climate change on rice water consumption and yield under different water management. Consumptive water footprint is an indicator of water use in relation to crop yield. It consists of two components: green (rainfall) and blue (irrigation) water. This study analyzed the impact of climate change on consumptive water footprint of rice (IR-36) under different water environments (i.e. saturated and water deficit). Kharagpur (eastern India) region was selected as a study area. In this study, historical (1987-2016) and future (2017-2100) climate data were collected from HadGEM3-RA based on RCP8.5 scenario. APSIM 7.10, a water-driven crop model (calibrated and validated with the experimental data) was used for historical and future simulation. Consumptive water footprint was projected to decrease by 13 and 11% (2030s), 8 and 7% (2060s) and 9 and 10% (2090s), respectively, from the historical value of 800 and 770 m³/ton under respective saturated and water deficit environment. The outcomes of this research could provide basic information for rice water management to cope with climate change.