What are the pros and cons of using crop residues or wastes for biofuel production?

Corn stover, straw, and other crop residues remaining after harvest can be an excellent source of organic material for biofuel production. They are considered waste products in many agricultural systems, so the additional money and/or energy that can be gained by farmers can provide a considerable boost to the overall farm budget. In addition, the fuels produced from these wastes offer a source of energy that doesn’t compete with food crops for arable land. Concerns have arisen mainly due to the lack of cover left to protect the resulting fallow fields from erosion from wind and rain. For this and other reasons, perennials such as switchgrass and miscanthus have gained in popularity as feedstock for biofuels, as they leave much more ground cover after harvest for the prevention of soil loss. For additional information, see “Residue Cover in Sustainable Energy Systems”. Andrew R. Moss, SARE Fellow, University of Maryland