Impact of Long-Term Conservation Reserve Program Enrollment on Soil Quality.

The Conservation Reserve Program (CRP) was developed in 1985 as a way to preserve environmentally sensitive agricultural lands. Although the CRP has gained popularity for its environmental conservation benefits, the CRP lacks a large body of research that quantitatively describes the effects of CRP enrollment on soil quality. This study compared physical, chemical and biological soil properties on active cropland, 30-year CRP land, 5-year CRP land, and an uncultivated fenceline (70-year, or more) in Meeker County, MN. The soil parameters measured were carbon-dioxide flux, water infiltration rate, bulk density, aggregate stability, total microbial biomass and total carbon. Results suggest that enrollment of land into the CRP is an effective way to recover high soil quality in unhealthy soils, although the rate of recovery varies between the measured parameters. In order to restore soil quality to near-native conditions, the land may need to be removed from cultivation for a period of 30 or more years.