May 14th, 2007
Distillers dried grains (DDGs), coproducts of converting corn into ethanol, are usually fed to livestock, but DDGs may soon be used to fight weeds and reduce herbicide.
Plant physiologist Steve Vaughn and colleagues with the Agricultural Research Service (ARS) at the National Center for Agricultural Utilization Research (NCAUR) are 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.
Vaughn’s work over the past few years 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, compared to 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 Mark 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. Rick 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 Rogers 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, but the nation’s increasing production of ethanol may create a DDG surplus that exceeds the current demand, Vaughn notes.