ARS | Publication request: Modeling soil carbon sequestration with EPIC and the soil conditioning index

Submitted to: USDA-ARS Research Notes
Publication Type: Other
Publication Acceptance Date: April 22, 2009
Publication Date: April 22, 2009
Citation: Franzluebbers, A.J., Beese, D. 2009. Modeling soil carbon sequestration with EPIC and the soil conditioning index. USDA-ARS Research Notes. JPC Research Note 15. 2009.

Technical Abstract: Increasing CO2 in the atmosphere is a concern, because of its potential to warm the planet. CO2 and other greenhouse gases act as a barrier to prevent heat escaping from the atmosphere. Prior to the industrial revolution, atmospheric CO2 concentration was about 280 parts per million (ppm). A delicate balance in atmospheric CO2 is maintained dominantly through photosynthesis by plants (input) and organic matter decomposition by microorganisms (output). The CO2 output has been increased in the past century by burning of fossil fuels, leading to the rising atmospheric CO2. Soils in the southeastern USA have been depleted of organic matter due to historical cultivation practices that encouraged decomposition of organic matter and that contributed to enormous erosion losses. Soil stores carbon as organic matter, which is essential to soil quality. Conservation tillage is a practice that can help restore organic C in soil. Long-term field experiments are needed to quantify how much soil organic C can be sequestered with conservation agricultural practices. However, results of long-term experiments are site and management specific, resulting in high cost of determination. Computer simulation models can be used as a low-cost method (but need testing) to predict changes in soil organic C sequestration with changes in management styles. This study showed that EPIC v. 3060 and the soil conditioning index (SCI) could be useful, relatively inexpensive, and expedient tools to determine soil organic C sequestration among different tillage and residue management systems in the southeastern USA. Routine use of the SCI in USDA – Natural Resource Conservation Service field offices with calibrated soil organic C estimates could help promote soil conservation and C offset trading. Further research is needed to determine applicability of approaches to a wider range of management situations.