LEXINGTON, KY - Biofuel research at the University of Kentucky may hold promise for Kentucky farmers to augment their incomes while contributing to national security. President Barack Obama last Wednesday announced that the Environmental Protection Agency has finalized its mandate that by 2022 the United States produce 36 billion gallons of biofuel. Last year's production level was at 11.1 billion gallons. "Reducing our dependence on foreign oil is still the right thing to do for our security," Obama said. "We can't afford to spin our wheels while the rest of the world speeds ahead."
On a rainy day last week, David Williams ventured out into the fields of Spindletop Farm where 2,000 acres are devoted to research and teaching. Williams, an associate professor and researcher at UK in turf grass science, usually works with turf grasses for golf courses, sports fields and lawns. His research has an added direction with the national drive to advance biofuels. He points up a small rise to four plots containing clusters of 12-foot-high grass, planted in rows like giant corn. The tall grass is Miscanthus x giganteus (MxG), a hybrid grass bred in Japan and now being studied around the globe for its promising capacity to produce biomass for conversion into biofuel or for use as a feedstock in energy production. This species looks like very large ornamental grass, and in fact was bred using a common variety of it.
The research with MxG is entering its third year at UK. Williams said that China has nurseries with many thousands of acres of MxG, and that China is the main source for the germplasm used in the UK research. MxG has also been studied for over 15 years in European countries.
MxG has a number of characteristics that make it attractive as a biofuel crop, according to Williams. It's a perennial that once established doesn't require replanting. It's sterile, producing no viable seed, so it's non-invasive. During dormancy, when the stems are harvested, mineral nutrients leave the stems to be stored in the plant's below-the-ground system, so those nutrients are not removed from the soil and the plant. It yields an abundance of biomass - much more than switch grass.
The UK research on MxG is at an early stage, and Williams said it would be premature to conclude that it will be a successful crop for Kentucky farms. A big challenge, Williams said, is in planting and establishing the grass. It's not as simple as sowing seeds or plopping seedlings into holes. Beneath the soil, between the stems and the roots, reside the rhizomes, the plant's reproductive organ. The gradual multiplication of rhizomes expands the stand of grass stems. The rhizomes can be harvested and planted to establish new plots of MxG. The thinking is that one acre of mature MxG would provide enough harvestable rhizomes to establish 10 new acres of the grass. The harvesting of rhizomes, with a method similar to potato harvesting, is much more advanced than the planting technology, according to Williams. The small research plots at UK were planted by hand, and engineering solutions will be needed to be able to do large plantings of MxG.
The five-year MxG research program is supported by the Sun Grant Initiative that was authorized by Congress in the 2002 Farm Bill, with funding from the U.S. Department of Transportation, the Department of Energy and the Department of Agriculture. UK's role in the project is to study the effects of nitrogen on the growth and quality of the grass. With three plots in four replications - one plot provided with no nitrogen, another with a moderate amount of nitrogen and the third with twice that amount - Williams said that the nitrogen or lack of it has made no observable differences among the three plots. Last year, UK sent their first harvest of stems for analysis to South Dakota State University, which is a regional administrator of the Sun Grant Initiative. Williams doesn't know the results of that analysis yet.
Williams said his research is a small piece of UK's total effort in biofuel/bioenergy research, which involves a number of researchers, departments and disciplines. Nonetheless, as energy cane, a hybrid developed from sugar cane, appears to be the bio-energy crop of the southern states, it could be that Miscanthus x giganteus will prove to be the best biofuel crop for Kentucky and other states that inhabit the transitional climactic zone, that area between the colder northern region and the hotter southern region. The soil in the UK plots is rich in organic matter, Williams said, but if it turns out that MxG can be easily cultivated on marginal land - land not usually put into crop production - that could make it all the more a winning crop for Kentucky farmers.