What would be the impacts of a viable market for corn stover? A partial equilibrium model and a linear programing model were used to determine to what extent the existence of a viable market for corn stover would affect the traditional corn-soybean crop rotation in the US. We find that with government support production of biofuel from corn stover could significantly increase. That boosts profitability of farming corn in combination with harvesting corn stover versus soybeans. We show that if corn stover is demanded for biofuel, then a major shift will be observed in crop rotations in the US.