511b Sustainable Strategies for Biofuel Production

Tom L. Richard¹, Gustavo Camargo¹, Rob Anex², and Ed Van Ouwerkerk². (1) Agricultural and Biological Engineering, The Pennsylvania State University, 225 Agricultural Engineering Building, University Park, PA 16802-1909, (2) Agricultural and Biosystems Engineering, Iowa State University, 3202 NSRIC Building, Ames, IA 50011-3020

Four strategies are analyzed for their ability to produce large quantities of biofuel feedstocks without negative impacts on food production or the environment. These include:

1. Organic wastes, including Municipal Solid Waste (MSW), food processing wastes, wood processing residues, livestock mortalities and manure.

2. Perennial crops (short rotation trees or grasses) on abandoned or marginal land, and as streamside buffers and roadside plantings.

3. Integration of energy crops with food crops to increase the productivity of existing agricultural land, without reducing food production, and with enhanced environmental outcomes. Strategies include a) cover crops (winter canola, winter barley, winter rye); and b) crop residues (corn stover, wheat straw, etc.) when harvested at rates that maintain or enhance soil carbon and limit erosion – with enhanced harvests possible in combination with the cover crops in example a).

4. Enhanced management of forest landscapes. Many U.S. forests are overstocked with small diameter non-timber species left over from generations of “high-grading” (taking out just the best timber species). Thinning is widely recognized as improving wildlife habitat and forest recreation as well as timber production. As with cover crops, forest thinning for biofuels can provide an economic incentive for environmental enhancement.

This paper examines these alternatives for productivity, environmental impacts, and energy and nutrient use efficiency, with particular emphasis on option 3, which has largely been overlooked in the public debate.