Landscapes marginal for grain productivity are those having low or negative profitability due to lower grain yield or high risk of crop failure. These are the first acres to come into production when cost and price changes increase profitability. Food grain, biofuel grain and potential cellulosic biofuel cropping systems are all competing for these acres. Unfortunately many of these areas are also vulnerable to degradation processes such as soil erosion, loss of soil carbon, and are disproportionate contributors to agrochemical runoff. The objective of this research is to assess the spatial extent of marginal soil-landscapes in the Central Claypan Area of Northeast Missouri under different cost and price scenarios. Spatial models of grain yield and yield risk were developed using a large database of corn and soybean yield maps and soil-landscape data (including SSURGO attributes and digital terrain models). This study allows strategic analysis of the potential feedstock areas for cellulosic biofuel crops in a way that minimizes competition of using acres for food grain.