When he moved from full-width tillage to strip-tilled corn 4 years ago, Fox Lake, Wis., farmer Jonathan Gibbs understood it would require more than simply a change in equipment.
Attending farm demonstrations of different strip-till units, and having several of his own fields custom strip-tilled in fall to evaluate in spring, allowed Gibbs to strategize equipment needs for his 1,000-acre corn, no-till soybean and wheat operation.
“We knew we couldn’t just park the soil finisher, hook up the strip-till rig to the tractor and expect the same results,” he says.
Formulating A Plan
Gibbs believes strip-till is attractive for better fertilizer placement, improved soil health and a more profitable farm operation, but he admits achieving all three of these objectives takes time.
One of his initial goals with strip-till was to see a financial benefit from the system, so he started with a search to find the right equipment, and determine when to build strips.
STRIP-TILL AS A SYSTEM. Fox Lake, Wis., farmer Jonathan Gibbs strip-tills about 525 acres of corn with an 8-row Dawn Pluribus coulter machine. He prefers spring strip-till because berms dry out faster and he can apply half of his nitrogen needs ahead of planting.
He runs an 8-row Dawn Pluribus coulter machine to strip-till about 525 acres of corn in spring, including 100 acres of corn-on-corn ground and the rest going into soybean stubble. With shallow topsoil in some fields, Gibbs says he chose the coulter system because it disturbs less soil and doesn’t turn up as many rocks into the strip.
After experiencing some washout of custom strip-tilled berms in fall, Gibbs settled on spring as the best time to get strips built.
“We really like the seed bed we get in spring because we’re were able to expose some of the soil, clear it off, aerate it and let it warm up faster,” Gibbs says. “For corn-on-corn I like to leave the stalks over winter, and we don’t run a chopping corn head. Because we leave stalks 16 to 18 inches high, they’ve gone through winter and are a little more brittle, so they handle easier in the spring.”
Gibbs may eventually add stalk-crushing devices to his combine, or run a 32-foot Brillion roller to minimize the risk of tire damage and get the stalks in closer contact with the ground in fall.
So far, corn-on-corn yields have been close to those Gibbs achieved with full-width tillage. He conducted side-by-side trials in 2012 and 2013 and found strip-tilled continuous-corn yields were about 3 to 5 bushels per acre below those harvested from conventionally tilled corn-on-corn ground.
But what Gibbs lost in yield, he more than made up for with cost savings by eliminating two tillage passes.
PLANTER ADJUSTMENTS. Gibbs plants with an 8-row Hiniker machine, with a triple-coulter setup in front. To improve 2-by-2-inch fertilizer placement, he removed the fertilizer tine and switched the row cleaners out for a Sunco Nutri Mate 3 system with the company’s row cleaners.
“We figured a tillage pass cost us $15 per acre and we were making three passes, so that was $45 per acre,” he says. “Strip-till cost us about $20 per acre, which includes applying fertilizer with the spring pass. We make one more fertilizing pass with a spreader, which is about $5 per acre, so we’re seeing about a $20 net benefit with our strip-till system.”
Last year, some strip-tilled corn-on-corn fields exceeded 200 bushels per acre, Gibbs says, and he’s optimistic that additional tweaks to his fertility program can boost yields even more.
“I also think that leaving the residue and mulch on top of the ground is helping, because sunlight isn’t hitting that ground as much before canopy — conserving moisture for the crop,” he says. “It’s hard to see a difference when we’re doing the 55 mph scouting from the road, but everything we’ve seen yield-wise and net dollar-wise is positive.”
Fertilizing With A Purpose
One of the primary reasons Gibbs moved to strip-till was to ensure more accurate placement of fertilizer.
With a mounted Montag fertilizer cart on the Pluribus unit, he applies about 200 pounds per acre of urea and 50 pounds of ammonium sulfate (AMS) in the strip for corn-on-corn ground.
For corn planted after soybeans, Gibbs applies 150 pounds per acre of urea and 50 pounds of AMS. The fertilizer is blended into the 8-inch-wide strip, about 4 to 5 inches below the soil surface.
Gibbs also variable-rate broadcasts potassium and phosphorus in spring, based on soil-test results, but he’s considering a fall application of potash banded below the surface with the strip-till rig.
“That is one thing I’m still trying to figure out because we are still solid-seeded, no-till soybeans,” he says. “If I start indexing a lot of phosphorus and potassium in corn, am I going to see waves of taller and shorter soybean plants every 30 inches?
“I might try banding a portion of our potash where the spring strip is going to be, but doing it the prior fall to avoid putting too much in the strip right before planting and potentially burning the seed.”
Gibbs uses soil sampling to identify areas where he can increase or decrease fertilizer application. He currently soil samples on 2 ½-acre grids every 3 years.
“What I’ve learned so far, is that some of our highest-producing areas are some our highest organic-matter content, which gets up to about 4.2 on our flatter, blacker ground,” he says.
Eventually, Gibbs plans to move to zone sampling and combine soil-sampling data, Veris data and yield data to identify low-, medium- and high-productivity zones to improve planting and fertilizing decisions.
“Right now, we fertilize to meet our 180- to 200-bushel-per-acre goals, but what we really want know is what planting population do we take those yield averages from?” he says. “One of our goals with the strip-till system is to find out where we can plant lower seed populations and intensively manage those areas.”
A ‘Busy’ Planter
For corn planting, Gibbs uses an 8-row Hiniker machine with Rawson coulters. The planter was originally built for ridge-till, but he modified the row units when he made the move to strip-till.
“We’re running a triple-coulter setup in the front,” Gibbs says. “We were using one of the Rawson coulters for 2-by-2-inch fertilizer placement, but one of the disadvantages was that the cornstalks would get trapped behind the tine, causing the coulter to plug.”
He removed the fertilizer tine and switched the row cleaners out for a Sunco Nutri Mate 3 system with the company’s row cleaners. He also added Totally Tubular steel tubes to place the fertilizer underneath the seed.
The modifications have improved fertilizer placement, ensuring the nutrients are placed below the ground, and he uses the row cleaners to skim off any corn residue or rocks left on the strip, providing a clean seed bed.
With the planter, Gibbs applies 4 to 5 gallons of ammonium phosphate (10-34-0) with zinc and Ascend plant growth regulator. The balance of urea is sidedressed when corn is a foot tall and before canopy, mixed with Agrotain nitrogen stabilizer.
“We have a busy planter,” Gibbs says. “But if we end up strip-tilling a couple weeks ahead of planting, we’ve had our ground seal back up. So it’s nice to be able to drop those Rawson coulters back in the ground to loosen the strip right in front of our planter unit.”