Mark Pokorny

Located near Clutier in Tama County, Mark Pokorny began hosting a demonstration site in Fall 2009 for the ILF/PFI cover crop working group.

“I was interested in trying a winter rye cover crop for the erosion benefits over winter and in early spring,” Mark said. “I had not considered the nutrient capture, organic matter increases and reduced weed pressure benefits that I saw in 2011.” This past harvest, Pokorny reported higher soybean yield following the cover crop and also saw reduced common waterhemp and lambsquarter weed pressure.

Pokorny rotates soybean with one or two years of corn or seed corn production. Spring full-width tillage with a soil finisher precedes corn planting and soybean is no-till planted into standing cornstalks. After soybean harvest in November 2009, he drilled replicated side-by-side treatment strips of winter rye cover next to “no cover” treatment strips. In April 2010, he used a disk and soil finisher to terminate the rye and prepare a seedbed for corn planted a few days later. Pokorny’s 2010 corn yields were not affected by the preceding rye cover crop (176 bu/acre following rye cover, 177 bu/acre in “no cover” strips). Rye cover and no cover treatment strips were re-established in Fall 2010.

In Spring 2011, he terminated the winter rye with a pre-emerge herbicide tank-mix of glyphosate, Authority, and First Rate. Non-GMO soybean was planted in May in 30-inch rows at 150,000 seeds per acre. Control of waterhemp and lambsquarter weeds was less than desired in “no cover” soybean; however, the soybean planted into the rye cover showed significantly less weed pressure. Over four replications, soybean yields averaged 68 bu/acre following rye cover and 60 bu/acre in “no cover” strips. 

Pokorny has not experienced increased insect or disease pressure in corn or soybean crops planted into winter rye cover. “I plan to expand my use of rye cover crops following seed corn production,” he said. “Any non-GMO soybean acres with a history of significant weed pressure will be planted into winter rye cover based on the results I experienced in 2011.”

Contact Information

Mark Pokorny
2310 S Avenue
Clutier, IA 52217
319/479-2269
pofarms@fctc.coop