The Climate Change Adaptation Potential of Irrigation in the Central United States

Keywords: Agriculture, Climate Change, Irrigation, Central United States
Session Type: Virtual Paper Abstract
Day: Friday
Session Start / End Time: 2/25/2022 09:40 AM (Eastern Time (US & Canada)) - 2/25/2022 11:00 AM (Eastern Time (US & Canada))
Room: Virtual 4

Abstract

Irrigation can increase current crop yields and reduce the impacts of climate change. However, future water availability is uncertain as groundwater withdrawal rates currently exceed recharge rates in key agricultural regions in the Central United States. We explore the effectiveness of both existing and expanded irrigation as an adaptation strategy through estimating the value of future groundwater used for irrigating maize and soybean. Specifically, we simulate maize and soybean growth at a 5-arcminute resolution for the contiguous U.S. using a gridded version of the Decision Support System for Agrotechnology Transfer model (pDSSAT). We examine both middle- and end-of-century conditions under 10 possible future climates across 2 emission trajectories (SSP245 and SSP585) and five GCMs that span the range of future temperature and precipitation change (i.e., warm and wet, warm and dry, hot and wet, hot and dry). To estimate the value of groundwater used for irrigation, we combine the relative yield difference between rainfed and fully irrigated simulations with an estimate of pumping costs from multiple groundwater availability scenarios. We find that planting date, cultivar selection, and irrigation adaptations can greatly reduce negative impacts of climate change and future crop water requirements, but are dependent on temperature and precipitation projections. The results from this study highlight areas where the crop productivity benefits of irrigation outweigh pumping costs, as well as those areas that may not be suitable for future irrigation.