Evaluating Carbon Sequestration in CRP and Restored Grasslands in the North Central U.S.

In recent years, much debate over global climate change has occurred. Anthropogenic activities such as burning of fossil fuels which release large amounts of carbon dioxide (CO₂) into the atmosphere are often implicated as a cause of climate change. Terrestrial sequestration of CO₂ as soil organic matter in cropland and restored grasslands has been proposed and promoted as a means to offset CO₂ emissions in the U.S.  A study was conducted to discover the relationship between age classes of Conservation Reserve Program (CRP) soils and the amount of organic carbon that is stored in the soil. Samples have been collected from five northern Great Plains states in an effort to set benchmark values for carbon sequestration rates for different year classes of CRP and the major soils associated with them. Study sites were selected and placed into a sampling matrix that classified the different CRP year classes along with native prairie and cropland as two controls. One sample point was taken for every ten acres within a field, and the sample locations were distributed between the soil series and landscapes present in the field. At each sample point, five cores were collected and the 0-15 cm and 15-30 cm portions of the cores were composited and analyzed for carbon content. From data evaluated thus far, there appears to be a clear relationship with the age of grassland and the amount of organic carbon that is stored within the soil. The potential threshold point for the system to store organic carbon has been obtained from the native prairie systems. The ability of restored grasslands to help mitigate the effects of anthropogenic releases of CO₂ will be discussed.