This paper demonstrates the need to integrate biophysical and economic data to assess the competitiveness of US agriculture to provide soil carbon (C) and participate in a market for C credits. The paper discusses alternative methods of calculating the costs of soil C sequestration and compares the cost of sequestering soil C in Iowa and Montana. Results indicate that the opportunity cost per Mg of sequestered C varies in response to regional resource endowments and net returns. Economic models show that Montana could sequester a relatively small amount of soil C annually at a lower opportunity cost per Mg than Iowa, but Iowa can sequester larger quantities more efficiently. These results are compared with estimates of the cost of C sequestration from other domestic and international studies, and suggest that US agriculture could be competitive in domestic or international markets for C reduction credits.
