Corn-based ethanol production in the United States has plateaued in recent years

Corn is the major agricultural input used in the United States to produce ethanol, which has accounted for over 40 percent of U.S. corn use in recent years. Rapid expansion of ethanol production in the past decade reflected a response to high crude oil prices, the Renewable Fuel Standard, and other factors. However, ethanol production has generally plateaued as oil prices have fallen and the gasoline market has hit a 10-percent blend constraint.