Optimizing cropping patterns under the influence of climate change

The world needs 70% more food by 2050, increasing the pressure on the available water resources. With the climate change threat approaching, the water stress will further be exacerbated that would adversely affect food security. In countries like India, with extensive cultivation of staple crops like paddy, there has been a rapid increase in the total water consumption. At the same time, cultivation of crops such as pulses and millets has not been sufficient to satisfy the nutritional requirements of India’s population. With the increased likelihood of droughts and floods due to the advent of climate change, it becomes imperative to achieve water, food, and nutritional security into the future. This study attempts to optimise cropping patterns to minimise future water requirement, while satisfying the nutritional and caloric requirements of future generations. We perform the analysis for the southern Indian state of Andhra Pradesh, where agriculture depends predominantly on irrigation. To achieve this objective of optimization, we collected bias-corrected climate datasets from three General Circulation Models (BCC-CSM2-MR, INM-CM5-0, MPI-ESM1-2 HR) that include future rainfall and temperature information from 2021 to 2050. Further, we collected crop-wise farm-level data of five major crops in the state - paddy, sugarcane, groundnut, sorghum, and red gram. The irrigation water requirement (IWR) of the selected crops was estimated using FAO’s CROPWAT model under two different scenarios - SSP 245, SSP 585. Further, we developed an optimization model to obtain the optimal cropping pattern that minimises water consumption. Future food requirements in terms of protein and calorie demands and arable land available for cultivation were used as constraints to perform this optimization. Preliminary results indicate that shifting from water-intensive crops like sugarcane to relatively more nutritious crops like red gram and sorghum has the potential to significantly reduce water consumption, while also enhancing the nutritional security of the region. Interestingly, the optimization results indicated that the southern part of the study region required more interventions in terms of crop diversification as compared to the northern part. Such insights could help decision makers to devise holistic policies, enhancing the water-food security under different climate change scenarios. Further, this research could be extended to domains such as economics, ecology, and energy to achieve overall sustainability in the agricultural sector.