Energy crop production has been proposed for land of poor quality to avoid competition with food production and negative indirect land use consequences. The objective of this study was to determine the land area requirements, biomass transportation distance, and expected cost consequences of restricting switchgrass biomass production, for use as biofuel feedstock, to marginal land relative to unrestricted land use. The USA soils capability classification system was used to differentiate between high quality land (Class I) and land of marginal quality (Class IV). Switchgrass biomass yield distributions were simulated for each of four land capability classes for counties in the Eastern Oklahoma case study region. For a 70 million gallons per year cellulosic ethanol biorefinery, restricting land use to capability Class IV (defined as marginal) increases the quantity of land required to support the biorefinery by 47%; increases biomass trucking distance by 218%; increases cost to delivery feedstock by 13%; and increases the expected cost to produce a gallon of ethanol by $0.19. In the absence of government restrictions, for-profit companies are not likely to limit energy crop production to land of marginal quality.