The Rotenberger family is finding that more than two decades of reduced tillage is helping them improve soil tilth and organic matter, stabilize yields and reduce labor requirements to help their operation function more efficiently and profitably.

Doug Rotenberger, his father Charles and his son Steve, no-till and strip-till corn, soybeans and spring wheat on 3,500 acres near Lisbon, N.D., in a zone that sees 15-18 inches of precipitation annually.

Their rotation used to include more small grains like winter wheat and barley, but the trend in their area has shifted toward adding corn and soybean acres, Doug says.

The family tried no-tilling soybeans in the late 1980s but stopped because they didn’t feel there were enough options for herbicides to control weeds. As herbicide and equipment options improved in subsequent years they returned to no-tilling, using a single-disc Case SDX drill to no-till winter wheat after spring wheat.

“I guess I was looking for something to reduce time or workload,” Doug says, noting his 78-year-old father still runs the combine and handles other miscellaneous tasks on the farm.

The Rotenbergers believe their long-term switch to no-till and strip-till has made a difference, as organic matter levels have come up from an average of 2% several years ago to 4-6% now.

Battling Residue

On the Rotenberger farm this year, 50% of their rotation is in soybeans, 35% corn and 15% wheat. Corn planting typically starts by April 24, soybeans by May 10 and spring wheat by April 15.

The Rotenbergers like to harvest spring wheat in late July or early August so they can seed cover crops afterwards, while soybeans are usually harvested in the first few weeks of September and corn by mid-October.

While reduced tillage has its benefits, Doug admits the family is still struggling to manage increasing amounts of crop residue generated by the shift in their rotation.

They’ve taken a two-pronged approach, implementing strip-till practices for corn and using a vertical-tillage tool to put residue in contact with soil and level used strip-till berms in the fall. They also vertical-till to manage soil conditions ahead of spring planting.

Several years ago the Rotenbergers committed to using a strip-till system for planting 30-inch corn and applying the bulk of their fertilizers in the strip, rather than knifing in nitrogen (N) and broadcasting and incorporating phosphorus (P) and potash in spring like most farmers in their area do.

For irrigated corn, after bulk spreading P and potassium (K) and about 100 pounds of urea in spring, they sidedress anhydrous before plants are knee high, and may also topdress the corn at tasseling with 28% N. They only sidedress the irrigated corn because those acres are sandier and hit-or-miss precipitation makes the practice more risky in dryland corn, Doug says. For dryland corn, P and K may go in as strips are built in the fall, as well as either ESN or anhydrous as an N source.

They haven’t purchased a strip-till rig, but instead have a co-op service use a 24-row SoilWarrior from Environmental Tillage Systems to build strips in the fall. Outfitted with row cleaners to sweep residue away from the row, they build strips 6-8 inches deep and 8-10 inches wide in the fall.

They tend to avoid building strips in spring due to manpower issues at the co-op and the limitations of their high-clay soils.

“There is ground between us and Fargo that gets a little sandy and you can do it in the spring, but for us it doesn’t work,” Doug says. “What might be dry in the fall may not be dry in the spring. In wet years, wheat stubble could be the most cumbersome thing in the spring if nothing is done with it, and that’s kind of why we went to strip-till. At least you had some black surface there to draw some sunlight.”

Corn is planted by Doug’s 16-row John Deere 1770NT planter, outfitted with Precision Planting’s DeltaForce auto down-pressure technology and Yetter SharkTooth row cleaners with CleanSweep control, rubber closing wheels and drag chains.

In general, the Rotenbergers are satisfied with the response they’ve seen from strip-tilling corn, as the switch has netted them up to a 20-bushel-per-acre advantage over conventional planting. But Doug notes that strip-till hasn’t overcome the effects of cool springs and summers they’ve seen in some years.

The increase in corn and soybean acres on the Rotenberger farm has driven up their use rate of P and K compared to their previous rotation with more small grains, and trying to account for the weather when making applications has proven difficult.

Last year, after pricing out N applications for their irrigated corn and concluding an aerial application of urea was the cheapest vs. applying 28%, they ordered an application of urea at tasseling after a 3-inch rain event had cleared out. But no rain fell after that and the fertilizer wasn’t utilized, Doug recalls.

Even at that, Doug estimates that more precise and efficient nutrient placement with strip-till let them reduce their N budget by 20-25%, and K and P budgets by 30-35%.

“If you were to broadcast what the requirements might be from the soil test, it would get pretty pricey,” Doug says. “So what we’re able to save by putting it right in that berm in the row doesn’t completely cover the cost of hiring them to do it, but it sure helps.”

Reducing Hairpinning

The Rotenbergers have also struggled with some hairpinning issues when their no-tilled soybeans followed wheat or corn.

Last fall was the first time in several years the Rotenbergers didn’t seed winter wheat, mostly due to poor prices and increased hairpinning issues. Two years ago, they switched out their Case IH SDX air seeder for a 40-foot-wide Amity 3800 to seed spring wheat and soybeans.

The problem with the Case IH machine, Doug says, was that the depth gauge wheels were next to the seed openers, so the gauge wheels would hold down debris and the opening disc would push residue to the bottom of the seed trench instead of cutting it. On the Amity, the gauge wheel is behind the opener and it also serves as a packer wheel, he says.

“From a hairpinning standpoint it’s a vast improvement,” Doug says, adding that soybean stands in their 15-inch spacings have improved. “We’ve got paired rows and a mid-row bander so we can apply a little extra fertilizer between the rows.”

For soybeans, they usually apply 25-30 pounds of MESZ — N, P, sulfur and zinc — with the mid-row banders. Doug says some of the soils in their area tend to be more sulfur deficient and soil test results aren’t always accurate, so they’ve addressed it with the MESZ and spring broadcasts of ammonium sulfate.

Residue Dilemma

In addition to strip-till, the Rotenbergers have been using a Salford RTS vertical tillage tool to get excess corn and wheat residue in touch with soil microbes and keep it in place.

They’ve made as many as one pass each with the Salford in fall and spring and are still evaluating the benefits. Doug says using the Salford tool has been necessary on their heavier riverbottom ground, which has some gumbo qualities, to prepare a suitable seedbed for corn.

In some cases, they’ve baled corn stalks after harvest, and they’ve even tried spraying biological products on corn stalks in the fall. Even after all that, big winds after harvest can blow residue around and cover up rows or leave piles of residue behind.

Two years ago they purchased a Calmer Corn Head for their combine to chop stalks at harvest. “We are seeing big benefits in sizing the residue and eliminating that mat of residue we could typically have in the spring,” Doug says.

Seeding Cover

The Rotenbergers are participating in a Conservation Stewardship Program to seed cover crops on their farm. After resurrecting an old mixer mill they owned, they’re blending a mix of oats, turnips and radishes that is seeded by the Amity drill after wheat harvest late July or early August. They seeded 600 acres of covers last year.

On ground where they’re grazing their black Angus beef cows, they seed 30 pounds of oats, 2 pounds of radish and 1 pound of turnips per acre, backing off on the oats to 20 pounds if the land isn’t being grazed.

Typically they graze the cows in pastures, but in the fall the animals are run on 600 acres of riverbottom where there is proper shelter and corn stalks available. They can also graze them on cover crops if there’s an available water source nearby. He hasn’t found the cattle bother the strip-till berms in the fall, especially if they’re let out after the soil has frozen.

Doug says when they have a longer fall season they see more benefits from the size and growth of the turnips and radishes, but if wheat harvest is delayed to mid-August and fall is short, they don’t get as much growth.

But they still feel soil tilth is improving.

“We did have a couple of fields grazed in early fall and winter, then used vertical tillage on it to even up the berms,” Doug says. “We noticed with the planter that the soil texture is better.”

*Editor's note: This article was originally published in the June 2017 edition of No-Till Farmer