Farming in north-central Illinois, Cade Bushnell doesn’t have the luxury of naturally high organic matter in his primarily sandy clay soils, or a consistent weather pattern he can count on each year to produce a bumper corn crop.
But Bushnell is fighting these challenges with flexibility by adopting strip-tilled continuous corn to bolster soil health, multiple approaches for residue management and calculated nitrogen applications to feed the crop when it most needs it.
“The big thing for me is I have to have a Plan A and a Plan B, not matter what I’m doing,” says Bushnell, who raises 1,300 acres of corn and soybeans near Stillman Valley, Ill. “Mother Nature is going to trump everything I really want to do, so I have to let her do her thing and I’ll work around it.”
These decisions are paying off for Bushnell as he averages more than 200 bushels per acre of strip-tilled corn-on-corn in some fields — comparable to his no-tilled corn-on-corn yields.
Continuous Corn Success
A veteran no-tiller, Bushnell moved to strip-tilled continuous corn 7 years ago, primarily to improve soil health on several fields with low levels of organic matter.
Some of Bushnell’s fields had organic matter content as low as 0.7% dating back to 1962, and it’s taken nearly 50 years to boost those levels to about 3.5%.
He uses a 12-row Dawn Pluribus coulter strip-till rig exclusively for corn-on-corn, but still no-tills all of his soybeans and about two-thirds of his corn.
“On my farms with poorer soil quality, I just didn’t see the benefit of going with a corn and soybean rotation in strip-till because I wasn’t growing enough organic matter with soybean residue,” he says. “Nothing builds organic matter like corn.”
Bushnell says he’s not seeing much of a yield difference between strip-tilled corn-on-corn vs. no-till. But he is seeing more consistent stands with strip-till, which he attributes to planting into a cleaner seedbed. The system also lets him reap the soil-enhancing benefits of the residue left on the surface.
“The goal is to get 95% of plants to produce a whole ear, and I can get that with no-till corn after soybeans,” he says. “But I’m not building as much organic matter and I was having more trouble getting those effective plant stands in no-till corn-on-corn. Strip-tilled continuous corn allows me to hedge my bets for the best yield.
“The biggest single benefit I see,” he adds, “is a more consistent yield because I’m not as weather dependent. I’m taking some of the variability out of the process.”
Further managing that variability, Bushnell began planting a cereal rye cover crop into a strip-tilled corn-on-corn field, which helps with residue breakdown and nutrient preservation. He typically seeds the cover into the old corn rows with his John Deere drill immediately following harvest and then kills the crop once it gets about 8 inches tall.
“Any taller and that root mass underneath the ground could really interfere with planting and I’d have trouble getting good seed placement,” Bushnell says. “Killing that cover about boot-top high, I’m seeing less corn residue in the field because it’s ramping up the soil-biological activity and supercharging residue breakdown.”
Residue Management, Not Destruction
Bushnell admits there is a longstanding stigma with a corn-on-corn system, and it takes time to realize the benefits.
Photo courtesy of Cade Bushnell
It took about 3 years for Bushnell to start seeing nitrogen cycling back into his soil once the residue began breaking down faster and feeding the soil.
“Nitrogen is locked up those first few years and there is a carbon penalty because of all the residue,” he says. “But the key is keeping that residue away from the corn plant.”
Bushnell has had instances where the shadow line from a piece of corn residue crossed the row, stunted the corn and made it a weed. High winds have also blown residue over the row, and strip-till gives Bushnell a “second chance” to move that residue off the seedbed.
The row units on his strip-till rig and 16-row Deere 1760 no-till planter are set up nearly the same for residue management, with both featuring Dawn’s floating trashwheels. Bushnell says he likes the setup because the row units move residue rather than blend it into the strip.
“I can do everything right, but if I don’t keep the residue away from the corn, I’m gambling,” he says. “I’ve had corn plants that were two collars behind because there is residue around them. In the right year that may not make any difference in yield. But in the wrong year it could make a big difference.”
This past fall, Bushnell added Calmer Bt Chopper stalk rolls to his Deere combine to move, rather than destroy corn residue. A late harvest last year and cold winter that followed prevented Bushnell from building fall strips, which he prefers to allow for a firmer seedbed. But the addition of Bt Choppers proved to be a worthwhile investment for spring strip-till, he says.
“It wasn’t a lawnmower-style blade, so it didn’t redistribute residue over the whole field, ” Bushnell says. “The residue was right in the old corn row where I wanted it, and it was a lot easier to strip-till into because there wasn’t much residue in the strip.”
Monitoring Nitrogen Application
Even more important than residue management for strip-tilled corn-on-corn, Bushnell says, is nitrogen management. He says there’s no ‘one-shot wonders’ for nitrogen application.
Photo courtesy of Cade Bushnell
Bushnell relies on as many as 5 applications of nitrogen in his strip-till system, starting with 100 pounds of ammonium sulfate (AMS) and 21 pounds of sulfur applied in spring along with his variable-rate spread of potassium and phosphorus.
Bushnell doesn’t apply any fertilizer with his strip-till rig, in part because he only strip-tills part of his operation and he prefers planter applications for consistency.
He applies 10 gallons of 32% liquid nitrogen in 2-by-2-inch placement with the planter on strip-tilled corn, and another 10 gallons of 32% is applied with a herbicide over the top using his Hagie sprayer.
“The herbicide is a carrier,” Bushnell says. “The reason being that if I don’t feed the microbes on the soil surface, they will rob the nitrogen from that 2-by-2-inch placement.”
He typically sidedresses the balance of nitrogen when corn is between shoulder and head-high, but he may also dribble on another 5 gallons per acre of nitrogen with the sprayer, depending on the health of the crop.
“I will dribble on every other row and I can get below the canopy, which allows me to fertilize 6-foot-tall corn if I need to,” Bushnell says. “It does require a good rain to incorporate, but this is my Plan B if I can’t get in and sidedress earlier.”
Bushnell may also make a foliar application of nitrogen and micronutrients, using Agro-Culture Liquid Fertilizer’s ferti-Rain product if fields are saturated by rain early in the growing season. Last year, several areas received 7 inches of rain when corn was about knee-high, resulting in significant nitrogen loss.
“I basically drove around and sprayed every wet spot with about 3 or 4 gallons per acre,” Bushnell says. “It definitely stopped yield loss and took 100 bushel corn and made it 170.”
Pest control is another key to a successful corn-on-corn operation, and Bushnell applies Capture LFR Insecticide in-furrow with the planter.
Wireworm and Japanese beetles have been problematic in the past, but Bushnell says the early application has worked well to minimize secondary pest problems.
“We’ve had out issues with the Japanese beetles, not so much the adults, but the grubs,” Bushnell says. “A lot of years, I could dig and find more grubs than corn, but we’ve been able to combat that problem with our insecticide treatment.”