With far fewer farmers required to feed many more people today compared to 60 years ago, the report states, something needs to change in rural America. in 1950, 15 percent of Americans were "directly involved in production agriculture." Today, it's less than two percent. Thus, the USDA says, "growing a domestic biofuels market is part of overall USDA rural strategy to help rebuild rural America."
Part of that diversity will come from figuring out ways to make cellulosic ethanol and other biofuels at reasonable costs using things other than corn. The Roadmap looks at ways to make advanced biofuels from, "switchgrass, soybean oil, corn oil, crop residues, woody biomass" and things like "biomass (sweet) sorghum, energy cane, and camellia." The USDA is much more confident than the EPA about the amount of biofuel the U.S can produce from dedicated energy crops like switchgrass and energy cane. The EPA predicts 7.9 billion gallons by 2022, the USDA says 13.4 billion. You can read the report for yourself here (PDF) and get more information over at Green Car Advisor.
[Source: USDA via Green Car Advisor]