Wednesday, 8 October 2008: 1:15 PM
George R. Brown Convention Center, 361C
GHG emissions trading markets are emerging in the US that allow farmers to sell emission offsets associated with adoption of conservation management practices, such as sequestering carbon (C) in soils through no-till. Our objective was to analyze the potential for GHG mitigation accounting for the influence of edaphic characteristics and climate on mitigation supply, as well as socioeconomic factors influencing farmer decisions to adopt conservation practices in the
Central US. Specifically, the Century Agroecosystem Model was used to simulate C sequestration in soils and crop yields based on climate and edaphic characteristics at the county scale, and an econometric model was used to conduct a cost-return analysis under the assumption that farmers would adopt no-till if it increased their profit margin relative to conventional management. The analysis also included the effect of no-till adoption on N2O emissions, crop yields and fuel usage. Among the factors, changes in N2O emissions coupled with soil C sequestration had the largest effect on adoption rates. At a price of 20 USD per tonne of CO2 eq. mitigation, results suggest that adoption of no-till in the eastern
Central US is reduced by half in an analysis including both C sequestration and changes in N2O emissions as part of the mitigation supply, compared to an analysis of C alone. In contrast, adoption of no-till more than doubled in the western Central US at the same price of 20 USD per tonne by including both GHGs in the supply calculation. According to the analysis, farmer decisions to adopt no-till were also significantly influenced by changing yields and fuel usage due to their impact on returns from grain production and GHG mitigation supply, respectively.