Effects of the Conservation Reserve Program on Hydrologic Processes in the Southern High Plains

Abstract:

The Southern High Plains Aquifer is a rapidly depleting resource that supports agriculture in parts of New Mexico and the Texas Panhandle. The development of the aquifer has changed the landscape and the water cycle of the region. This study illustrates the evolving patterns of land use and the effects of cultivation, from irrigated to dryland farming to the countermanding influence of the Conservation Reserve Program (CRP). Previous research indicates that greater recharge rates occur under cultivated land in the Southern High Plains than under unbroken soil: the transition to cultivation causes increased recharge, under both dryland and irrigated management, though most recharge still occurs through playa lakes. The Conservation Reserve Program takes land out of crop production, replacing the land cover with something more like the natural ecosystem. This may decrease recharge below fields, and reduce runoff that feeds playa lakes; or, CRP may help stabilize playa lakes, increasing recharge. Changes to the water cycle are investigated at the field scale using the System Approach to Land Use Sustainability (SALUS) crop model, and at the regional scale with the Landscape Hydrology Model (LHM), and compared with historical data and water table elevations.