U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


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Published in Genetic Improvement of Bioenergy Crops.


Both native and non-native forage species other than switchgrass are less commonly considered as potential lignocellulosic feedstocks for bioenergy in the United States. These species hold potential as bioenergy feedstocks because of the experience and infrastructure that is already in place for management and harvest, and in certain areas of the country they have greater yield potential than switchgrass or other feedstocks. The forage grasses consist of temperate cool-season (most commonly C3) grasses as well as tropical or sub-tropical warm-season (C4) grasses. Some legume species may also play a significant role in supplying useful bioenergy feedstocks. Most have been researched and used as a pasture or hay crop and are currently grown over millions of hectares of fertile as well as Conservation Reserve Program (CRP) land throughout the United States. Research on genetic variability and breeding systems has revealed great potential in improving these crops for bioenergy. However, research on the majority of these species has only recently begun concerning the potential as a renewable energy resource. The largest hurdles for forage crops to become a significant portion of the biomass needed for renewable energy are the current high price for these hays (as feed for livestock) and the high water and fertilizer inputs needed for production. This chapter will not attempt to address all of the 10,000 species of grasses, of which 47% are C4 (Sage et al. 1999) or the numerous perennial forage legumes, but will be limited to those considered to have the greatest potential of contributing to the billions of tons of biomass needed for replacement of fossil fuels over the coming years.