Ethanol "Leftover" Has Weed-Fighting
Potential By Jan
Suszkiw May 14, 2007
Distiller's dried grains (DDGs)coproducts of converting corn
into ethanolare usually fed to livestock. But a new use could be on tap:
fighting weeds and reducing herbicide use.
That's the hope of plant physiologist
Vaughn and colleagues with the Agricultural Research Service (ARS) in Peoria, Ill. There, at the National
Center for Agricultural Utilization Research (NCAUR),
Vaughn is among approximately 100 scientists seeking to identify new,
value-added uses for farm-based commodities like DDGs and help bring them to
commercial fruition by developing novel processing technologies.
In laboratory, greenhouse and field studies over the past few years,
Vaughn has shown that applying DDGs to soil as a surface mulch can not only
suppress weeds, but also bolster the growth of tomatoes and some turfgrasses.
In one study, for example, Roma tomatoes in DDG-treated plots yielded 226
pounds, versus 149 pounds from untreated control plots.
Vaughn attributes some of the increase to nitrogen, phosphorus and
other nutrients released by the DDG mulch as it decayed.
In another study, using various analytical methods, NCAUR collaborator
Berhow is seeking to identify, measure and monitor the activity of the
chemicals in the DDG mulch that may have kept chickweed, annual rye and other
weeds from germinating.
Boydston, an ARS collaborator at Prosser, Wash., tested the mulch's weed
control in potted ornamentals, including roses. He observed that DDGs worked
best when applied to the soil surface, because mixing them into the soil harmed
both ornamentals and weeds alike.
On another front at Peoria, ARS chemist
Harry O'Kuru is examining DDGs for phytosterols, lecithin and other
substances with potential use as health-promoting food ingredients.
The team's efforts to expand the market for DDGs are timely. In the
Midwest, ethanol producers generate 10 million tons of DDGs annually. Farmers
buy most of it for about $80 per ton and feed it to cows and other ruminants.
However, the nation's increasing production of ethanol may create a DDG surplus
that exceeds the current demand, Vaughn notes.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.
about the DDG research in the May/June 2007 issue of the agency's
Agricultural Research magazine.