A strip-till forum in Iowa offered a range of solutions and suggestions for breaking down residue and jumpstarting nutrient cycling in soils.
By Jack Zemlicka, Technology Editor
Heading into his fourth year of strip-tilling, Jeremy Swanson is still waiting to see what kind of a yield improvement he’ll get after moving away from conventional tillage.
Swanson farms about 800 acres of corn and soybeans south of Dayton, Iowa, with his father, Charlie.
Their first two seasons of strip-tilling were under radically different climate conditions and Jeremy says it’s been difficult to get a read on how much — if any — yield boost they’ve received from the practice.
“This past year we were in a pocket of the state that got absolutely no rain, so we had a hard time making triple-digit corn yields,” he says. “The year before, we were right in the middle of a wet pattern. With the extreme years, it’s been hard to grasp the yield payoff.”
That’s not to say the Swansons aren’t benefitting in other ways, including reduced fuel use and saving time on labor in the field. Mother Nature’s wrath aside, Jeremy says he realizes it takes a patient approach at the beginning to realize the long-term benefits of strip-till.
But as relative newcomers to the farming practice, the Swansons are looking for ways to refine their operation at an early stage and avoid potential missteps that could set them back.
One of their major concerns is residue management in corn-on-corn acres because large amounts of stalk and leaf residue is left over.
The Swansons received some food for thought on this topic from other strip-tillers during a 2013 daylong forum organized by Brokaw Supply Co., an equipment and precision-farming dealer in Fort Dodge, Iowa. Veteran strip-tiller and Brokaw co-owner Dave Nelson brought together 65 current and future strip-tillers for the first-time event.
Strip-tiller Dave Nelson (with microphone) and Brokaw Supply Co. organized a daylong strip-till forum attended by 65 current, and future, strip-tillers. The event featured an in-depth discussion on options for managing corn-on-corn residue.
“I can tell there is a big hunger for strip-till out there,” Nelson says. “Even guys who have been doing this for 10 years are trying to pick up new things and are eager to learn — not because they have to, but because it pays off.”
Time Will Tell
Corn-on-corn residue management was one of the hottest topics discussed at the event, says Nelson.
There are a variety of options for strip-tillers to manage residue, including using a chopping corn head, letting the stalks stand, running a stalk cutter through the field or using a vertical-tillage tool.
The best practice often depends on how long the farmer has been strip-tilling, Nelson says. The longer you have been strip tilling, the faster the residue will break down.
Getting the microbial activity active and healthy in your soils is the key to naturally occurring residue decomposition, Nelson says. In the early years of strip till to kick start the breakdown, some growers apply a mixture of 28% and humic acid. This speeds up microbial activity and kick starts the process.
“I came away from the event thinking about our residue management on 500 acres of corn-on-corn this year, and how we’ve gotten to the point where I can see the natural breakdown in each field,” he says. “My microbial nutrients are alive and well, and I’m not as concerned with sizing residue. It’s naturally breaking down on its own.”
The same method works for Ben Fehl, who strip-tills corn and no-tills soybeans in La Porte City, Iowa. He started strip-tilling corn-on-corn several years ago and says a healthy population of earthworms, and patience, paid off with better residue management.
“Our experience is the longer we’ve done corn-on-corn, the more residue disappears on its own,” Fehl says. “However, for someone transitioning into strip-till, a vertical-tillage pass or a chopping corn head can get things started. It all depends on what your tolerance is.”
Eric Ivarson strip-tills corn-on-corn in Larabee, Iowa, and takes a technological approach to managing his residue. He uses RTK guidance on his home-made strip-till machine to move through fields and spot-manage heavy residue.
“We built our own tri-placement strip-till machine, which has a turbo coulter blade followed by a strip-till shank with high-clearance coulters in the back,” Ivarson says. “It’s built for heavy-duty residue and we made it a little taller so we can run a little deeper and faster.
“We can go through with our tractor in the fall and come back in spring to lay down 28% fertilizer and freshen the strip. It’s really worked well for us.”
Some farmers in the area run a chopping corn head to break down residue into smaller pieces to allow for more surface area at the ends of stalks, says Nelson.
Then they’ll run a double wavy coulter to freshen the seedbed and allow it to dry out faster in the spring.
“People have done this and not necessarily seen a yield increase,” he says. “But it gives them peace of mind that their strips will warm up and dry out faster.”
The Swansons say they’re still looking for the best approach to manage their corn-on-corn residue. They’re currently using a Case IH 1063 corn head but may partner with their neighbor to use their John Deere corn head for harvesting next season, in exchange for doing some strip-tilling on for him on his farm.
Jeremy also says he plans to conduct a baseline study of microbial growth in his soils at some point and also do a dig this spring with a back hoe to see what compactions look like in his strip-till fields.
“We haven’t done anything quantitatively yet, but we want to get a standard for microbial growth,” he says. “The goal is to get a grasp on how our soils are changing as we get several years down the road.”
But Jeremy says it was comforting to learn from experienced strip-tillers that mechanical sizing of residue may not be a long-term necessity, rather a starting point to promote microbial soil growth.
“We did some corn-on-corn fields back in 2012 and we rotated out of those last year and threw some soybeans on there,” Jeremy says. “This bought us another year to have residue breakdown before we switched back.”
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