Cropland erosion estimates simulated by RUSLE2 and WEPP: Results from two initial studies

Authors: Wells, Robert - Rob; Flanagan, Dennis; Langendoen, Eddy; MCGEHEE, RYAN - Iowa State University; Bingner, Ronald - Ron; Frankenberger, James - Jim; Locke, Martin; MOMM, HENRIQUE - Middle Tennessee State University; Renschler, Chris - Christian; SRIVASTAVA, ANURAG - Us Forest Service (FS); Vieira, Dalmo; Tsegaye, Teferi

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: USDA soil erosion technologies are critical for conservation management planning at the farm level, and therefore contribute to long-term agricultural sustainability and productivity. Soil conservationists utilize soil loss prediction technology to evaluate the impact of different management strategies to reduce soil loss and maximize soil conservation. In this study, two current USDA soil loss prediction technologies (RUSLE2 and WEPP) used in the United States to develop conservation management plans were examined. The technologies were compared as currently used by conservationists for management plan implementation and then compared using equivalent climate specific conditions, with similar input parameters for management, soils, terrain (slope length and gradient), and crop yields. Results of the comparisons generally show similarities in soil loss trends for a range of soil types, managements, terrain characteristics, and crop yields, but differ for predominantly clay and sand textured soils, very large slope lengths and gradients, and no-till management. The differences between the technologies were among others related to differences in soil erodibility characterizations, slope length and gradient effects on runoff generation, and cover crop managements. This study shows soil loss trends that are independent of climate inputs evaluated. The comparison results provide important insight to model tendencies that can be useful in understanding the application of the technologies in conservation management planning.

Technical Abstract: Sustainable agriculture begins with reliable conservation management planning. Conservation management planning addresses soil loss control while coupling productivity and profitability on the farm together with environmental stewardship. Traditional row crop agriculture utilizes soil loss prediction technology to estimate the impact of different management strategies to minimize soil loss and maximize soil conservation. In this present study, two current USDA soil loss prediction technologies used in the United States to prescribe conservation management plans (RUSLE2 and WEPP) were examined. The technologies were compared first as designed and intended for management plan implementation (17,525 simulations) and second for equivalent climate specific conditions (18,480 simulations), using similar input parameters for management, soils, terrain (slope length and gradient), and crop yields. Results of the simulations generally show similar soil loss trends for soils, managements, terrain characteristics and crop yields. Simulated soil loss estimates disagree particularly for clay texture soils and no-till management. Both studies show these trends independent of climate inputs evaluated. Though the comparison results provide important insight to model tendencies, there are still open questions remaining regarding climate.