U.S. Department of Agriculture: Forest Service -- National Agroforestry Center


Date of this Version

February 2006


Ruark, G.,S. Josiah, D. Riemenschneider, and T. Volk. (2006). Perennial crops for bio-fuels and conservation. 2006 USDA Agricultural Outlook Forum – Prospering in Rural America. 1-17 February 2006, Arlington, VA. [On-line]. Available: http://www.usda.gov/oce/forum/2006%20Speeches/PDF%20speech%20docs/Ruark2806.pdf


Perennial woody crops have the potential to contribute significantly to the production of bio-fuels while simultaneously helping to provide a wide range of conservation benefits. Among these benefits are increased biological diversity in the landscape, conservation of soil and water resources, maintenance of forest ecosystem productivity and health, contribution to the global carbon cycle, and provision of socioeconomic benefits. Short rotation woody crops, like hybrid poplar and willow, grow rapidly and can reach 15-25 feet in height after only three years. Currently, non-irrigated yields can be sustained at about 5 dry tons/acre/year and are increasing as plant breeding, nutrient management, and weed control advances are made. The high hemi-cellulose and cellulose content of woody biomass result in favorable net energy conversion ratios of 1:11 when co-fired with coal and 1:16 when undergoing gasification. Directing this wood fiber into bio-fuels would benefit both the energy sector and forest and farm landowners, while providing an array of conservation benefits and ecological services. The amount of biofuel that can be sustainably produced each year from perennial crops is potentially very large. The next Farm Bill affords an opportunity to insure that this potential can be more fully realized.