An Analysis of the Climate Change Mitigation Potential through Soil Organic Carbon Sequestration in a Corn Belt Watershed

Abstract:

The sequestration of carbon constitutes one of major options in agricultural climate change land-based mitigation. We examined the carbon sequestration potential of alternative agricultural land uses in an intensively farmed Corn Belt watershed. We Used downscaled data from eight atmosphere-ocean general circulation models (AOGCMs) for a simulation period between 2015 and 2099 with three emission pathways reflecting low, medium and high greenhouse gas scenarios. The use of downscaled data, coupled with high resolution land use and soil data, can help policy makers and land managers better understand spatial and temporal impacts of climate change. We consider traditional practices such as no-till corn-soybean rotations and continuous corn and include also switchgrass, a bioenergy crop. Our results show that switching from conventional tillage continuous corn to no-till corn-soybean can sequester the equivalent of 156,000 MtCO₂ of soil organic carbon with a sequestration rate of 2.38 MtCO₂ ha^-1 yr^-1 for the simulated period. Our results also indicate that switchgrass can sequester the equivalent of 282,000 MtCO₂ of soil organic carbon with a sequestration rate of 4.4 MtCO₂ ha^-1 yr^-1 for the period. Our finding also suggests that while climate change impacts corn and soybean yields, it does not have a significant effect on switchgrass yields possibly due to carbon fertilization effect on switchgrass yields.