Double cropping, a system in which more than one crop is produced per year in a land area, helps to increase food and feed production in the United States. But the impact of double cropping on production of biomass (crops grown to be converted to fuel) has not been evaluated. Such cropping systems have been successful in the eastern and southern United States. If they can be adapted to the relatively short growing season of the extremely large and agriculturally productive north-central region of the United States, biomass production potential can be greatly increased.