Soil management practices, such as tillage intensity and approaches to soil fertility, significantly alter the paths of the C cycle in agriculture soils. More specifically, we believe that soil management practices influence the role of agricultural soils in sequestering soil organic C. Currently, there are opportunities for producers to participate in voluntary C trading markets and conservation stewardship programs; However, the potential for C sequestration in cropping systems with distinct management practices has not yet been fully evaluated. Consequently, in this study we are taking an on-farm approach to assess the ability of three cash grain production systems to sequester C. We collected soil samples in four distinct regions in Illinois to a depth of 60 cm. In each region, samples corresponded to systems under organic, conventional, and conventional no-till corn-soybean production. Samples were collected in the spring prior to any major field operation. Samples are being fractionated to determine soil organic C and particulate organic C. Results will help to determine the relative potential of three typical Midwestern farming systems to accumulate soil C and contribute to reduction of greenhouse gas emissions.