New approach for organic weed control

(Photo courtesy of Dan Humburg, South Dakota State University)

A research scientist in western Minnesota is testing a new approach to weed control for organic farms. His idea is to cut the weeds down with a fine grit propelled through specially designed compressed air nozzles.

U.S. Agriculture Department research agronomist Frank Forcella, based in Morris, said he came up with the concept a few years ago:

"It seemed like a crazy idea," he said. "But it simply wouldn't leave my mind."

Early tests with a hand-held nozzle proved the sandblasting concept worked. But instead of sand, Forcella uses a softer, organic product: ground corn cobs. The material is powerful enough to kill the weeds but not harm young corn, soybean or other plants.

A team at South Dakota State University in Brookings is building a four-row prototype (above). Forcella hopes to begin field testing it later this month.

Organic farmers don't use chemical weed killers, so they largely rely on plowing to keep unwanted plants down. Forcella said if his concept works, farmers may get an added bonus. He said instead of corn cobs, farmers could use nutrient-rich material like ground alfalfa or canola seed meal. Besides killing weeds, the grit would also help fertilize the growing crop.

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