On an early August morning, Justin Knopf points out a patch of pigweed growing above his canopy of grain sorghum.
It’s the scourge of any crop field—growing in resistance to even some of the most aggressive chemical treatments. Yet, on this outing, the Gypsum, Kansas, farmer looks at the invasive weed with a glass-half-full mentality.
“Honestly, the field is better than I thought it would be with no herbicide,” he said.
Knopf wasn’t sure of the outcome when No-till on the Plains Director Steve Swaffer asked him to participate in an intercropping study this summer with three other farmers from across Kansas. The concept went against his normal routine of combatting pigweed, known as palmer amaranth. Knopf was told once he planted the acreage, he couldn’t apply herbicides or pesticides, instead relying on Mother Nature’s biological warfare.
The weapons? Buckwheat, guar, flax, mung bean and clover, to name a few of the greens growing in between Knopf’s sorghum rows.
The goal is to see how well cover crops choke out unwanted weeds and attract beneficial insects like lacewings and lady beetles, which feed on pests like sugarcane aphids, Swaffer said. The hope is farmers can save dollars per acre by not having to spray while building their soil health.
A Sustainable Agriculture Research and Education program grant through the U.S. Department of Agriculture helped fund the study, he said. The grant paid for some of the sorghum seed, intercropping seed and custom farming rates.
“You might not have to spray for aphids two or three times, or maybe not even once,” Swaffer said, adding the study allowed farmers to explore something they might not normally have tried otherwise.
“The thing about these four guys, they wanted to try to learn from it,” he said. “The SARE grant gave them the opportunity to do so without risk.”
