Irrigated agriculture in the United States: Current status and future frontiers

The United States (U.S.) plays a pivotal role in global food security, with its extensive irrigated agriculture being essential for both domestic and international food supply. This literature review assesses U.S. irrigated agriculture highlighting regional disparities, long-term trends, crop diversity (especially water-intensive commodities) and interaction between irrigation practices and water availability (including groundwater depletion and climate change impacts), along with the role of policy and advanced technologies in promoting water management. This study primarily utilized data from the USDA Census of Agriculture spanning from 2003 to the most recent 2023, Cropland Data Layer, and MIrAD-US irrigated area data, using robust geographic information to analyze the data. The findings identified and evaluated key challenges facing the U.S. irrigation sector, including water scarcity, inefficient water management practices, groundwater depletion, regulatory constraints, and socioeconomic factors. The results show that California, Nebraska, Arkansas, Texas and Idaho are the most irrigated states in the U.S. representing 50% of the total irrigated land in the U.S. We observed a significant shift in irrigated land from the western U.S. toward the east, including key states such as California, Nebraska, and Texas. Stronger groundwater policy and monitoring are needed to regulate irrigation pumping and rising costs in vulnerable regions. Expanding access to advanced irrigation technologies for smallholders will be critical to reduce groundwater depletion and enhance resilience under increasing water scarcity and climate change. • U.S. irrigated land increased until the 1990s and has stabilized since. • Top irrigated states vary in water source, groundwater dominates overall. • Corn and soybeans expanded irrigated areas, alfalfa, cotton, and rice declined. • Low-flow irrigation methods rising, soil moisture sensors lead to scheduling tech. • Irrigation shifts eastward, and policy needed for sustainable water use.