Adapting irrigated agriculture in the middle Rio Grande to a warm-dry future

Authors: SAMIMI, MARYAM - Oklahoma State University; MIRCHI, ALI - Oklahoma State University; TAGHVAEIAN, SALEH - Oklahoma State University; Moriasi, Daniel; SHENG, ZHUPING - Texas A&M Agrilife; GUTZLER, DAVID - University Of New Mexico; ALIAN, SARA - Oklahoma State University; HEREEMA, RICHARD - New Mexico State University; WAGNER, KEVIN - Oklahoma State University; HARGROVE, WILLIAM - University Of Texas - El Paso

Submitted to: Journal of Hydrology: Regional Studies
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2022
Publication Date: 12/15/2022
Citation: Samimi, M., Mirchi, A., Taghvaeian, S., Moriasi, D.N., Sheng, Z., Gutzler, D., Alian, S., Hereema, R., Wagner, K., Hargrove, W. 2022. Adapting irrigated agriculture in the middle Rio Grande to a warm-dry future. Journal of Hydrology: Regional Studies. 45.101307. https://doi.org/10.1016/j.ejrh.2022.101307.
DOI: https://doi.org/10.1016/j.ejrh.2022.101307

Interpretive Summary: Climate-informed water management is essential for agricultural activities in desert environments. We used the Soil and Water Assessment Tool model to analyze long-term tradeoffs of possible land and water management interventions to adapt irrigated agriculture to growing water scarcity in the Middle Section of the Rio Grande Basin (MRG), U.S. under a projected warm-dry future. Results indicate that status quo irrigation management in the region cannot sustain the current crop mixes due to dwindling fresh surface and groundwater resources within the 21st century; extreme interventions such as aggressive deficit irrigation or stopping the cultivation of alfalfa generates moderate water savings for perennial pecan crops but the region will remain vulnerable to intensive, prolonged droughts. Strategies for future agricultural water sustainability in the study area could include transitioning to relatively drought- and salt-tolerant crops, desalinating brackish groundwater for irrigation, and developing water markets to increase flexibility in water use. These findings will inform producers, water resource managers, and water decision and policy makers think of realistic strategies to sustain agricultural production in the region under the challenges of a changing climate.

Technical Abstract: Study Region: Middle Section of the Rio Grande Basin (MRG), U.S. Study Focus: We analyzed long-term tradeoffs of technologically possible land and water management interventions to adapt irrigated agriculture to growing water scarcity in a desert environment under a projected warm-dry future. We investigated nineteen different intervention scenarios to evaluate potential watershed-scale agricultural water savings and associated water budget impacts in the MRG. The interventions are based on (i) management innovations of growers in implementing deficit irrigation and changing cropping patterns using existing crops, (ii) changing cropping patterns by introducing new alternative drought- and salt-tolerant crops, and (iii) limitations of the soil and water assessment tool (SWAT) model to perform scenario simulations. New hydrological insights for the region: (1) status quo irrigation management cannot sustain the current crop mix due to dwindling river water and likely fresh groundwater depletion within the 21st century; (2) existing cropping and irrigation interventions create limited water savings; and (3) deficit irrigation of alfalfa or removing it from the crop mix allows moderate water savings to sustain high-value perennial pecan crops but the region will remain vulnerable to intensive, prolonged droughts. Strategies for future agricultural water sustainability in the study area could include transitioning to relatively drought- and salt-tolerant crops, desalinating brackish groundwater for irrigation, and developing water markets to increase flexibility in water use.