A study published in the journal Environmental Science & Technology found almost 80 percent of current farmland in the United States would have to be devoted to raising corn for ethanol production in order to meet current biofuel production targets with existing technology.
The 2007 Energy Independence and Security Act set a goal of increasing U.S. biofuel production from 40 billion to 136 billion gallons of ethanol per year by 2022.
However, researchers at Colorado State University said the law makes assumptions about technological developments and the availability and productivity of farmland.
Lead researcher W. Kolby Smith and colleagues used satellite data about climate, plant cover and usable land to determine how much biofuel the United States could produce.
To meet the biofuel goals with current technology, farmers would either need to plant biofuel crops on 80 percent of their farmed land or plant biofuel crops on 60 percent of the land currently used to raise livestock, the study found.
Both options would significantly reduce the amount of food U.S. farmers produce, it found.