Farmer driven water conservation policy on the Ogallala aquifer reduces the environmental footprints of crop production

Authors: CASTANO-SANCHEZ, JOSE - New Mexico State University; Rotz, Clarence; STEINER, JEAN - New Mexico State University; GOLDEN, BILL - Kansas State University; Spiegal, Sheri

Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2025
Publication Date: 2/19/2025
Citation: Castano-Sanchez, J.P., Rotz, C.A., Steiner, J., Golden, B., Spiegal, S.A. 2025. Farmer driven water conservation policy on the Ogallala aquifer reduces the environmental footprints of crop production. Agricultural Water Management. 310(2025):109370. https://doi.org/10.1016/j.agwat.2025.109370.
DOI: https://doi.org/10.1016/j.agwat.2025.109370

Interpretive Summary: The Ogallala Aquifer underlies 5.6% of the continental United States and spans eight states. It provides water for almost 2 million people and supports the agricultural economies of arid and semi-arid regions of the US Great Plains. Water has been severely depleted in the aquifer, and continuing with business-as-usual withdrawals puts the aquifer, and the agricultural economy dependent upon it, at risk. We found that farmer driven water-conserving cropping practices reduced not only the environmental impacts of water consumption, but also reactive nitrogen losses, fossil energy use and greenhouse gas emissions. The main driver of the reduction in environmental impact was the reduction of water use in crop irrigation, followed by changes in land use or crop selection strategies where more water-demanding crops (corn and soybean) were replaced by less water-demanding crops (sorghum and wheat). Adopting policies to conserve irrigation water can be a viable solution to stabilize the Ogallala Aquifer water levels in the future along with other environmental benefits.

Technical Abstract: The Ogallala Aquifer underlies 45 million hectares, supporting the robust agricultural economy of the US Great Plains and providing water for about 1.9 million people. The aquifer is renewable only on geologic timescales and has been severely depleted, and long-term viability is threatened. Pumping reductions of 25-30% on a decadal scale are required to stabilize water levels. Legislation has been passed in Kansas to reduce groundwater extraction while supporting productivity and economic viability. One program is entitled “Local Enhanced Management Areas” (LEMA), a farmer driven water-conservation approach. Our objective was to study the environmental benefits of implementing water-conserving cropping systems in the Sheridan-6 LEMA (one of 4 LEMAs). The Integrated Farm Systems Model (IFSM) verified with region-specific databases was used to compare simulated cropping systems within the LEMA to those in the surrounding region using conventional crop irrigation management. We found that LEMA irrigation management, which includes reduced irrigation and altered cropping, has provided environmental benefits with only a slight reduction in yields. Totaled over the LEMA, reductions were found for blue water consumption (28%), reactive N losses (1.4%), fossil energy use (22%) and GHG emissions (20%). Considering the environmental intensities per unit of grain produced, LEMA policies decreased blue water (24%), energy (18%), and C footprints (15%). The exception was the N footprint which experienced a slight increase due to reductions in crop yields. The main driver of the reduced impact was the decrease of water use in crop irrigation, followed by changes in crop selection strategies where more water-demanding crops (corn and soybean) were replaced by less water-demanding crops (sorghum and wheat). Replicating LEMA-type policies more widely across the region can be a viable solution (environmental and economic) to stabilize the Ogallala Aquifer water levels for the future, as demonstrated by this and previous research.