Widespread reliance of rainfed crops on upwind irrigated agriculture in India

Rainfed crops account for approximately 40% of India’s food production and support 60% of its livestock. Although linked to oceanic monsoon rainfall, their productivity also depends on terrestrial evaporation, particularly in the non-monsoon season. However, the degree to which rainfed crops also rely on moisture sourced from upwind irrigated areas, remains largely unknown. Using a combination of models and observations, we show that upwind irrigated crops contribute 7%±6% of the rainfall over rainfed areas, rising to 15%±10% during the pre-monsoon months. In the absence of this input, water stress experienced by rainfed crops can increase by 5–10% during the crucial mid to late crop growth phases, potentially affecting yields. Our results reveal an unrecognized atmospheric link between irrigated and rainfed agriculture, which is overlooked in current agricultural policies. Planning and managing these systems in an holistic manner can help strengthen regional food and water security under future climates.