Updegraff, Karen (SD School of Mines & Technology, Institute of Atmospheric Sciences, Rapid City, SD, 57701; Phone: 605-394-1989; Fax: 605-395-6061; Email: Karen.Updegraff@sdsmt.edu)


Potential for Soil Carbon Sink Enhancement in Three Northern Great Plains States


K. Updegraff *, P. Zimmerman, D. Kliche, W.J. Capehart, M. Price


The Big Sky Regional Partnership has prepared an assessment of carbon storage potential on agricultural lands in a 3-state region (SD, MT and ID).  The assessment is based on climate-zone level modeling using the CENTURY biogeochemical model, and provides information on current rates of soil carbon change as well as potential rates given various management assumptions.  While all three states are currently net carbon sinks with respect to agricultural soils, Montana manifests the highest total rates of net SOC increase due largely to its extensive areas of cropland and rangeland. In addition, it has the largest current CRP enrollment (3.4 m acres).  South Dakota has by far the largest area of cropland under no-till management as well as the largest area of harvested cropland. The greater importance of corn and soybeans (as opposed to winter wheat) in South Dakota agriculture give it the highest potential for enhanced carbon uptake due to increased no-till adoption.  Idaho has the least potential for agricultural sink enhancement, due largely to its more limited area of harvested cropland and rangeland.