Modeling soil and water conservation

Authors: Flanagan, Dennis; Wagner, Larry; CRUSE, RICHARD - Iowa State University; Arnold, Jeffrey

Submitted to: Journal of Soil and Water Conservation
Publication Type: Book / Chapter
Publication Acceptance Date: 6/11/2020
Publication Date: 12/15/2020
Citation: Flanagan, D. C., Wagner, L. E., Cruse, R. M., and Arnold, J. G. 2020. Chapter 24. Modeling soil and water conservation. In: Delgado, J. A., Gantzer, C. J., Sassenrath, G. F., Editors. Soil and Water Conservation: A Celebration of 75 Years. Ankeny, Iowa: Soil and Water Conservation Society. pp. 255-269.

Interpretive Summary: Soil erosion by water and wind is a national and international problem. This was recognized in the United States during the Dust Bowl during the 1930’s. Federal erosion scientists in the Soil Conservation Service and then in the Agricultural Research Service conducted soil erosion experiments in the field, and collected wind, rainfall, runoff, and soil loss data. Their efforts led to the development of empirical erosion prediction tools in the 1960’s for water erosion (Universal Soil Loss Equation) and wind erosion (Wind Erosion Equation). Since that time, numerous adaptations as well as new natural resource models have been developed by both federal and university scientists, to estimate the impacts of climate drivers on on-site soil resources (soil loss, nutrient losses, productivity, etc.) and off-site water and air quality (sediment transport in streams, pollutant losses, dust emissions, etc.). The newest modeling tools simulate the physical processes that occur when either a rain or wind storm occurs on a land surface. These processes include soil particle detachment, sediment transport, and sediment deposition. Additionally, other related processes including infiltration, runoff, plant growth, residue decomposition, soil tillage disturbance, chemical losses, etc. This paper provides information on the range of natural resource modeling tools developed within the United States, and impacts scientists, university faculty and students, conservation agency personnel, and others with interest in or tasked with conserving soil and water resources. Models provide a rapid, easy, and cost-effective way to determine the effects and potential benefits of various land management and conservation practices on soil and water resources.

Technical Abstract: Great strides have been made over the past 75 years in conserving the precious soil and water resources within the United States. The earliest national soil conservation efforts began when the USDA Soil Conservation Service (SCS), formed in response to severe soil erosion by wind causing the Dust Bowl in the Great Plains during the 1930’s. In addition to working with farmers and landowners to implement soil conservation practices on the land, SCS also conducted research at 35 soil conservation experiment stations located across the U.S. These locations provided long-term natural rainfall/runoff plot data, that allowed development of the Universal Soil Loss Equation (USLE) as the first widely used erosion prediction model. Modeling efforts after the USLE expanded into effects of erosion on soil productivity, runoff and water quality from agricultural lands, watershed-scale runoff, sediment, and pollutant losses, and systems for process-based predictions of water or wind erosion. Wind erosion research and modeling was a direct response to the Dust Bowl, with the empirical Wind Erosion Equation (WEQ) first published in 1965. All these modeling tools were designed to help conserve soil and water resources. This article will look back at earlier modeling efforts, describe current state-of-the-art models, and discuss future modeling of soil and water conservation practices.