Michael Vos

Using manure, evaluating fertility programs and working closely with agri-businesses are keys to growing above-average yields and improving profits for Oskaloosa, Iowa, strip-tiller Michael Vos.

But above all, says Vos, improvement comes from paying attention to details.

Vos strip-tills all of the corn that he and his father, Don, grow on their 2,000 acres. They also grow soybeans and market 8,000 head of wean-to-finish hogs a year. In addition, Michael is the software sales manager for Ag Leader in Ames.

Years ago, the Voses cultivated all corn and soybean ground. They switched to strip-till about 8 years ago on their corn acres. They no-till all of their soybeans.

Strip-Tilling Manure

In the fall, Vos applies liquid hog manure on 30% of the corn acres.

"We apply hog manure with a drag hose and an applicator with Dietrich sweeps," he says. "The manure is injected at an angle to the previous crop's rows. The Dietrich knives minimally disturb the soil. In the spring, sometimes you can barely tell where the manure was put on fields."

Vos comes back in the spring on the acres where manure was injected and strip-tills with a 12-row Dawn Pluribus strip-till rig with 30-inch spacings. The rig has a 6-ton Montag dry fertilizer cart and, using RTK auto-steer, he lays strips 15 inches from the previous row.

"We run a lot of side-by-side tests on our farm," says Vos. "We've compared corn yields where we applied hog manure in the fall and strip-tilled it in the spring — with and without potash, sulfur and boron. We see an advantage of placing those nutrients in the strip right below the plant."

Iowan Michael Vos strips both corn after soybeans and corn-on-corn in the spring with a 12-row Dawn strip-till rig.

In Mahaska County where Vos farms, corn yields average 140 to 150 bushels per acre, he says, but he's shooting for fields that average 180 to 200 bushels or more. He says reaching this goal requires more management, so one of the "extra" things he does is applying 2 1/2 gallons per acre of chelated liquid zinc in furrow with Keeton seed firmers.

Vos applies chelated zinc on all of the corn acres with their 12-row John Deere CCS planter. He uses auto-steer on the strip-till and planter tractors, along with Ag Leader's Integra monitor with the ParaDyme system.

Each tractor follows the same A-B lines. Vos pulls the strip-till rig with a New Holland 8050 tractor that's rated around 280 horsepower and uses a Deere 8320RT tracked tractor for planting.

On the other 70% of their strip-tilled corn acres, Vos applies a mix of dry fertilizer comprised of nitrogen, phosphate, potash and micronutrients. Some of the fertilizer is DAP and AMS — both of which contain some nitrogen — and some of the nitrogen is encapsulated urea.

Vos uses auto steering on his strip-till and planter tractors. Each tractor follows the same A-B lines. (Photos courtesy Michael Vos)

"We've had mixed results with encapsulated urea and the jury's still out," Vos says. "We're testing to see whether encapsulated vs. non-encapsulated urea is better. We originally thought encapsulated urea would eliminate some of the sidedressed nitrogen that we do.

"That would work in a perfect year when we have a 1-inch rain every week in June. But in the past 3 years, the rain has really dumped in June and we haven't had a perfect year."

In the first 30 days after planting corn, the soil typically is not warm and the nitrogen remains in the encapsulated urea, Vos says.

"In 2011, we had 4.5 inches of rain in one shot and 2 to 3 weeks later, we had yellow corn where the nitrogen leached away. We had to sidedress nitrogen," he adds.

Strip-Tilling Corn-On-Corn

About 70% of the corn Vos grows comes after soybeans, while the rest is corn-on-corn. He grows continuous corn on fields with sandy soils, while the corn coming after soybeans is raised on fields with high levels of clay. If all of the fields had sandy soil, Vos says he'd grow 100% corn-on-corn.

"We've been getting some yield hits in corn-on-corn because of the spring rains," Vos says. "The yield drag is 10 to 50 bushels per acre, depending on the field and the weather. That's because all the previous year's corn stalks create a cover for the soil, which takes more time and heat to warm up and dry out."

Vos uses two strategies to manage corn-on-corn residue.

"We don't have stalk choppers on the corn header yet, but do have knife rolls, and we cut corn as low as possible," Vos says. "On the fields with a higher percentage of clay, we run a Case IH vertical-tillage implement over the corn stalks, setting it just deep enough to mix up the stalks and break them down more quickly. So far, I'd give this strategy a B-minus."

Find Business Partners

Moving beyond average yields requires more than technology and management, Vos says. It includes identifying and relying on suppliers who do more than sell an input.

"For example, we work with Sean Blomgren of Boone, Iowa, who owns Blomgren Seed and sells DeKalb and Asgrow seeds," Vos says. "Sean is more than a seed guy. He knows my goals. Before he would sell me any seed, Sean told me to write down the top five characteristics of all my fields."

Blomgren fills bulk-seed containers and weighs them because Vos weighs the seed he plants with a scale on the planter.

"The amount of seed in bulk seed containers rarely comes out exactly what you need," Vos says, "but the boxes Sean fills have exactly the pounds we need. He delivers the boxes to us and marks the name of the field on each box. If I need 81 acres of seed, that's what's in the box. He knows the plant populations and knows that we do variable-rate planting. That attention to detail is what we need to grow yields that we want."

Working with Blomgren, Vos has increased the plant population and yields in fields where there have been low soil-fertility results.

"Our onfarm research shows we get more yields from higher populations and Sean is supportive of this idea," Vos says. "Where we had been planting 29,000 to 30,000 seeds per acre, we're now at 34,000 seeds per acre."

Vos has found high soil-fertility test results for nitrogen, phosphorus and potassium where fertilizer has been applied in the strips for corn.

After growing corn in these strips, the rows may still test very high for nitrogen, phosphorus and potassium. This can be the case even when soil between the strip-tilled rows is tested, and the same nutrient levels sometimes are low.

"Our onfarm research has shown that by strip-tilling, we can get a soil environment for every corn plant and a high-fertility zone," Vos says. "Because every seed is planted in a high-fertility zone, we have been able to increase populations.

"We can increase populations because we have supplied enough nutrients for the growing season. This requires technology systems to place the fertilizer accurately and then plant the appropriate seed in the strip. And this attention to detail pays yield dividends for us."