Impacts of Conservation Reserve Program on Soil Health.

The Conservation Reserve Program (CRP) was initiated in 1985 to convert highly eroded cropland to a permanent cover that provides many ecosystem services. However, little is known about how CRP affects soil health. The possibility of CRP to improve soil and environmental health is important in order to inform sustainable management decisions. However, these impacts of CRP on soil health likely vary across time and the landscape making recommendations difficult. We designed a chronosequence experiment across Iowa and Minnesota to address these issues. We sampled over 200 soils with CRP being in practice from 0 to 40 years. We also controlled for landscape position by collecting soils at each site from the shoulder-slope, back-slope, foot-slope, toe- slope, and undulating landscapes. Here we present the effect of CRP on several physical, chemical, and biological indicators of soil health – soil bulk density, total organic C, total N, potentially mineralizable C and N – and how these indicators vary with time since conversion to CRP and across different landscape positions.