ARS | Publication request: Soil carbon sequestration estimated with the soil conditioning index

Submitted to: USDA-ARS Research Notes
Publication Type: Other
Publication Acceptance Date: February 14, 2011
Publication Date: February 14, 2011
Citation: Franzluebbers, A.J. 2011. Soil carbon sequestration estimated with the soil conditioning index. JPC Research Note 23. 2011.

Technical Abstract: Rapid and reliable assessments of the potential of different agricultural management systems to sequester soil organic carbon are needed to promote conservation and help mitigate greenhouse gas emissions. The soil conditioning index (SCI) is a relatively simple model to parameterize and is currently used by the USDA Natural Resource Conservation Service (NRCS) to predict relative changes in soil organic carbon. However, it is currently only used as a non-quantitative tool to determine the trend in soil organic carbon response. The SCI is based on three important conditions that affect soil organic carbon: 1) Organic material grown or added to the soil, 2) Field operations that alter organic material placement in the soil profile and that stimulate organic matter breakdown, and 3) Erosion that removes and sorts surface soil organic matter. We hypothesized that a consistent relationship between SCI and soil organic carbon derived from several field studies conducted throughout the southeastern USA could be developed so that SCI could become a quantitative tool for estimating soil organic carbon in a diversity of soils and cropping systems in the region. Our objective was to calibrate SCI scores against published soil organic carbon data derived from field experiments under various management systems throughout the southeastern USA. With the successful calibration of the soil conditioning index (SCI) to field-based estimates of soil organic carbon, prediction of soil carbon sequestration is now possible under a multitude of farming systems throughout the southeastern USA. Location-specific climate and soil conditions are accounted in the Revised Universal Soil Loss Equation (RUSLE2) and these factors are important in setting the stage for predicting how conservation management practices will sequester soil organic carbon under a diversity of environments. This development is important for land managers to understand impacts of their decisions on carbon sequestration.