Today, agriculture is at a crossroads. It is receiving increased attention as the nation is concerned about its ability to meet food, feed and fiber demands along with increasing fuel demands. This chapter examines the use of crop residues in a conservation tillage system as a source of cellulosic fuel, as well as the economic potential of growing a dedicated energy crop to meet the demand for cellulosic feedstocks.
There are economic and conservation trade-offs to consider when thinking about harvesting a crop residue such as corn stover for use as a feedstock. Crop residue left on the soil surface provides important agronomic benefits that influence yield, including reduced erosion, improved water retention, the recycling of nutrients and improved soil health. Studies have shown that removing residue from fields negatively affects crop yields and can outweigh the financial gains from harvesting residue for bioenergy. If crop residue removal is to become a sustainable strategy for supplying energy feedstock, more research is needed on acceptable levels of residue removal.
Growing dedicated energy crops on marginal agricultural land offers a potentially viable option, particularly in the Southeast. An example crop is switchgrass, an herbaceous perennial. This chapter analyzes the economic feasibility of growing switchgrass in various scenarios that take into account emerging issues in establishment, production, harvest and handling. Stand establishment and lifespan are critical variables when evaluating the economics of switchgrass, as are the availability of a buyer and the costs associated with long-term storage and transportation. The chapter also discusses the role policy incentives play in the financial feasibility of switchgrass production, particularly the Bioenergy Crop Assistance Program (BCAP).