Are there alternatives to corn for companies to produce ethanol for biofuel?

Corn is among one of the most common crops grown throughout the United States due to its many uses in the products we use and buy. Ethanol production is an example of a by-product corn produces for several companies in the US due to its convenience and that the carbon footprint for ethanol production is much lower than gasoline but has a few disadvantages. For example, corn crops result in nitrogen and phosphorus runoff which pollutes both our air and groundwater in the Central Valley resulting in more greenhouse gas emissions and poor water quality. Because of the versatility and environmentally friendly benefits of corn-based ethanol, there seems to be a few alternatives for plant based-ethanol that would use less land and would be locally produced. A possible replacement that is being looked upon is sugar beets. According to research at MIT, sugar beets produced marginally more ethanol than corn but further research is being done whether or not beets would be more agriculturally friendly than corn.