PERENNIAL CROPS FOR BIO-FUELS AND CONSERVATION

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 bio- fuel 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. Sustainable Land Management In the United States, forestry and agriculture are both faced with the challenge of meeting an increasing demand for goods, as well as for an expanding array of ecological services, like clean water, soil conservation, and wildlife habitat, often from the same lands. With the nation's population expanding by more than three million annually, all this will need to occur on a fixed or shrinking land base. An emerging critical challenge is the need to develop sustainable approaches to producing renewable biomass crops to help meet our nation's energy needs. In this regard, perennial plants like trees and shrubs have the potential to provide large quantities of biofuel feedstock, while also providing a wide array of ecological services and revitalizing declining rural economies. Biomass currently provides about 10 percent of the global primary energy supply (IEA 2002). Projections are that this proportion will need to increase dramatically to meet growing energy demand. Given a relatively fixed land base, the production of energy crops will compete with traditional agricultural and forestry uses of land. Clearly, it is essential that agriculture and forestry work together to create integrated biomass production systems that landowners can use to help meet our nation's growing energy demands. Producing fast-growing short rotation woody crops (SRWC) on agricultural lands is one such approach that shows considerable promise. When produced in integrated systems, SRWCs combine the goals of sustainable forestry with those of sustainable agriculture at multiple temporal and spatial scales (Ruark 1999).