Analysis of Soil and Water Conservation Benefit of Conservation Reserve Program

Abstract: The Conservation Reserve Program (CRP) in the United States has been implemented for 35 years. The analysis and evaluation of its soil and water conservation benefits can provide experience and reference for the construction of China's the Grain for Green Project. Changes in CRP area and soil and water conservation benefits were analyzed based on CRP-related data obtained from the USDA Farm Service website and erosion rate data from the 2017 National Inventory Summary Report. From 1986 to 2020, the land area participating in CRP showed a bimodal change, with the largest area in 2007 reaching 1.498 million km². The largest area of land types involved is Cropland, accounting for about 93%, and the largest area after the transfer of CRP is also Cropland, which is about 59%. During 2006-2017, soil, nitrogen and phosphorus reduction losses were 2318.28 million tons, 3.20 million tons and 0.64 million tons, respectively. When the CRP area reached 12 thousand km², the soil, nitrogen and phosphorus sequestration no longer increased with the increase of the abandoned Cropland. There is a positive linear relationship between carbon dioxide absorption and CRP participation area, and the cumulative fixed CO2 amount from 2006 to 2017 is about 504 million tons. The U.S. land fallow protection project has significant soil and water conservation benefits, reducing soil erosion, nitrogen and phosphorus loss, and playing an important role in improving the ecological environment.

Key word: Conservation Reserve Program; soil loss; nitrogen; phosphorus; Carbon dioxide