No-till can work
An Iowa Learning Farms partner, John Kielkopf, grows corn and soybeans near Hedrick in Keokuk County. His dad, Ron Kielkopf, started no-till on their southeast Iowa farm in the early 1990s when no-till drills were introduced. John and his dad believe their no-till system does less damage to soil structure compared to a full-width tillage system, and long-term no-till has improved their fields’ water infiltration.
“After a big rain, I can see the water standing in the planter wheel tracks in tilled fields, and can’t even see the planter tracks in no-till fields. I think this shows where the water is infiltrating,” says John.
Iowa Learning Farms works with many farmers across the state who are demonstrating conservation farming practices while remaining profitable. ILF farmers share their experiences with others to help build a Culture of Conservation. They host field days, speak at workshops, or chat one on one with other farmers interested in making changes on their own farms.
About half of the Kielkopfs’ corn acres are planted no-till, and half are planted following a single spring soil finisher pass. Corn is in a corn-soybean rotation, and almost all the soybean acres are planted no-till into standing cornstalks.
John uses a split-row planter to plant corn in 30-inch rows and beans in 15-inch rows. “I believe soybean yield response is there most years to justify the 15-inch rows,” he says. “We like the 15-inch rows for faster soybean canopy and better weed control.”
John is particular about adjusting his planter setup based on soil conditions at planting. For corn, row units are equipped with row cleaners and in-furrow seed firmers. In dry soil conditions, a wavy coulter and cast-iron closing wheels are used on row units. In moist soils, John removes the wavy coulter and one cast-iron closing wheel and replaces it with a spiked closing wheel to break up sidewall compaction. He adds drag chains to ensure soil crumbles into the seed furrow.
For soybean planting, John runs wavy coulters and cast-iron closing wheels in all conditions. The fields are grid-sampled every four years, and variable-rate dry phosphorus and potassium fertilizer are applied as needed. Fall-applied anhydrous ammonia supplies nitrogen for corn.
John recognizes potential for glyphosate-resistant weed pressure and manages his herbicide program accordingly. “We use a full rate of a preemerge herbicide on every acre — corn and beans,” says John. “On no-till acres we plan to use 2,4-D as an inexpensive control for winter annual weeds. If spring conditions delay preplant spraying and grassy weeds are emerging, we switch to glyphosate for a burndown application. Every field starts clean, gets a full rate of residual herbicide, and beans are sprayed with a full postemerge rate of glyphosate. Using multiple modes of herbicide today equals fewer weed resistance problems down the road.”
The crop system leaves more residue. “We scout extensively during the growing season and haven’t seen significant disease pressure,” he says. “We make an effort to choose disease-resistant corn hybrids.”
Lundvall is field coordinator for ILF.
This article published in the March, 2012 edition of WALLACES FARMER.