Adaptive crop switching for irrigated agriculture in response to climate change in the Western U.S.

Abstract

Adaptive irrigation strategies are crucial for balancing water use, economic viability, and food security in the arid Western United States. However, as a key indicator vital in regulating agricultural productivity and crop irrigation, water use efficiency (WUE c ) is becoming increasingly complex to estimate due to climate change. This study explores the critical role of key meteorological drivers, such as maximum temperature (tmax) and vapor pressure deficit (vpd), and their impacts on crop-specific WUE c . Future impacts are also assessed through integrating machine learning models with climate projections from the CMIP6 framework under SSP2–4.5 and SSP5–8.5 scenarios to forecast WUE c trends from 2025 to 2099. Based on WUEc projections, crop-switching strategies were designed to optimize land allocation among cereals in the Imperial Valley and Lower Gila River regions. Results suggest that reallocating cereal crops under SSP2–4.5 can reduce water consumption by up to 13.7 %, while increasing farmers’ profits (up to 44.8 %) and calorie production (up to 2.7 %). Under the warmer SSP5–8.5 scenario, sustaining profit (up to 39 %) and calorie gains (up to 10.2 %) would require up to 9.5 % more water. These findings highlight the importance of crop-switching as a practical adaptation strategy and emphasize the need for region-specific approaches to ensure resilience to climate change. The research underscores the potential of climate-driven decision-making to enhance agricultural sustainability in water-scarce environments. • Maximum temperature and vapor pressure deficit as the key factors in regulating crop water use efficiency. • Crop water use efficiency declines sharply under SSP5–8.5, while corn and wheat show more resilience. • Crop switching of corn, durum wheat and winter wheat reduces 14 % water use and boosts 45 % profits under SSP2–4.5. • Under SSP5–8.5 crop switching increases water use by 9.5 % and calorie production by 10.2 %.