The state of Iowa possesses the largest quantity of corn stover in the United States. With a representative survey we examine what Iowa crop farmers think about harvesting and selling corn stover and to what degree they may be interested in providing stover to a biorefinery. Iowa farmers are in an overall learning phase regarding corn stover yet believe that harvesting stover will require an increase in capital investment, additional managerial knowledge and a well-developed support infrastructure. The data suggests some degree of farmer ambivalence regarding what institutional support would be needed to facilitate market entry. Statewide, only 17% of Iowa's farmers currently express interest in harvesting their stover; though 37% are undecided. The farmers who are interested in marketing stover tend to be: younger, will be farming in 10 years, are at least somewhat knowledgeable about stover, manage large amounts of land and have hectares currently in continuous corn rotations. Regionally, farmers in North Central, IA-the Iowa region with the highest capacity to produce corn stover tended to be more interested in harvesting stover. Environmental concerns that appear to be important stover supply barriers as farmers who anticipate the negative impacts of corn stover removal on environmental quality tend to be less interested in harvesting corn stover. Overall, the results of this study strongly suggest that future supply assessments consider farmer participation more explicitly and forego arbitrary assumptions regarding farmer behavior as previous supply analyses may have overstated the proportion of farmers interested in harvesting stover. (C) 2010 Elsevier Ltd. All rights reserved.