Evaluation of Conservation Performance in Cropland Regions of the United States Using Process-Based Models.

In order to investigate whether regionalization of the Natural Resource Conservation Service’s Conservation Management Tool (CMT) is necessary we developed an evaluation framework where we i) generated county-specific scenarios for dominant farming practices and key conservation practices related to soil erosion and soil organic C (SOC) macro concerns that are estimated within CMT, ii) modeled these scenarios in 12 Land Resource Regions using RUSLE2 and CENTURY, and iii) compared predictions with CMT scores. Despite a ten-fold difference in estimated SOC sequestration rates estimated by CENTURY, regional differences in response to management were not statistically significant (P < 0.05). The RUSLE2 scenarios predicted significantly higher erosion rates for the South Atlantic and Gulf Slope Cash Crops, Forest, and Livestock Region than for the Central Great Plains Winter Wheat and Range, Central Feed Grains and Livestock, and East and Central Farming and Forest Regions (P < 0.05). These results suggest that CMT scoring for the soil erosion macro-concern could be improved by regionalizing weighting within the CMT and that the soil quality macro-concern does not appear to need to be regionalized.