A perennial grass that grows as tall as 13 feet, requires little to no fertilizer, and can be stored away in bales almost indefinitely could be the next hope for efficient ethanol production.
At least that's the thinking of researchers from University of Illinois at Urbana-Champaign who have been field testing a sterile grass known as Miscanthus giganteus, a distant cousin of switchgrass. In a report released Wednesday, the researchers said that the biofuel crop proved in field tests to be significantly more productive than other crops like corn in producing biomass for ethanol--an alternative to gas.
"By using Miscanthus...we can produce ethanol using a lot less land than we're using at present doing this with corn," crop sciences professor Steven Long, who led the study, said during in a presentation of the research. His work will also appear in this month's journal Global Change Biology.
The U.S. government has a goal of producing enough ethanol to offset one fifth of gasoline use in the country, but by using corn or switchgrass as ethanol feedstock, it would take about 25 percent of U.S. cropland out of food production, according to the researchers. In comparison, to produce the same amount of ethanol with Miscanthus, it would take 9.3 percent of the acreage for agriculture, they said. In the U.K., the grass is commercially used for energy production.
In the last year, Long led a field study across Illinois to test the production of Miscanthus against switchgrass, which has drawn a lot of interest in the United States as a source of feedstock for ethanol. The group found that Miscanthus can outperform switchgrass annually by producing as much as 2.5 times more ethanol feedstock in the same acreage. Also, Miscanthus is like switchgrass in that it does not require chemicals, but Miscanthus is potentially nine times more efficient at converting sunlight to biomass, according to the researchers.
Miscanthus similarly dominates corn at 2.5 times the feedstock production.
"One reason why Miscanthus yields more biomass than corn is that it produces green leaves about six weeks earlier in the growing season," Long said. In Illinois, the crop also stays green until late October and corn's leaves die by the end of August.
Another reason to like the crop? It collects more carbon in the soil than corn or soybeans, Long said. "In the context of global change, that's important because it means that by producing a biofuel on that land you're taking carbon out of the atmosphere and putting it into the soil."
Still, he said, there could be even better crops to investigate, and Miscanthus itself could be improved. The crop, for example, requires a laborious planting process in the United States.