Author
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Richard Jr, Edward |
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Submitted to: Sugar Journal
Publication Type: Abstract Only Publication Acceptance Date: 3/29/2010 Publication Date: 4/13/2010 Citation: Richard Jr, E.P. 2010. USDA-ARS Efforts in Expanding the Region for Growing Sugar Cane and Complimentary Sugar Crops for Bioenergy. Sugar Journal. 72(10):10-11. Interpretive Summary: Technical Abstract: There is an urgent need to develop second generation feedstocks to supply the additional 16 billion gallons of non-corn biofuels required in 2022 under the Renewable Fuel Standard passed in 2005. As part of the final regulations for the implementation of these standards, EPA has designated sugarcane ethanol as an advanced low carbon renewable fuel that can lower greenhouse gas emissions by 50% and ultimately can help the world mitigate against climate change while diversifying America’s energy resources. Much of the needed expansion in biofeedstock production will come from the southeastern U.S.(SE) as this area has the highest rates of net primary productivity (NPP, essentially the net increment of annual growth) due to long growing seasons and generally abundant rainfall. Increasing emphasis in the conversion of plant material to fuel is being placed on the production of “drop-in” biofuels such as butanol, diesel, and jet fuel that can be used directly in existing engines. Though efforts to convert cellulosic crops and residues such as bagasse to these drop-in fuels are evolving, they are not nearly advanced as is the conversion of sugar to these fuels. As sugar cane is grown further from the equator in Louisiana, cold tolerance is an important trait in the USDA-ARS’s sugar cane breeding efforts at Houma, LA. Cold tolerance is primarily gained by crossing high sugar-producing varieties with sugar cane’s wild relative, Saccharum spontaneum, and from its near relatives Miscanthus and Erianthus. Early-generation hybrids from these crosses are cold tolerant and have high biomass yields, but their sugar:fiber ratios are too low for them to be considered as new varieties for the sugar industry without further backcrossing to sugar cane varieties. This does not preclude them from being grown as bioenergy feedstocks where both the sugar and fiber could be converted to fuel opening the door to expanding acreages of sugar cane outside the traditional cane growing areas of the SE. A recent estimate based on the success of growing these high fiber sugar cane varieties in a number of states in the SE is that an additional 3.8 million acres could be planted from Texas to the Carolinas. Biorefiners want to be able to process feedstocks over the entire year; hence USDA researchers at Houma are also exploring the growing of complementary sugar-containing crops with the higher fiber sugar cane varieties. Crops being evaluated include sweet sorghum and tropical maize that would be planted and harvested on an “energy plantation” prior to the start of the sugar cane milling season and tropical beets that could be planted in the fall and harvested and processed 12-months later with the sugar cane. Results from these evaluations will be presented. |
