For Fairfax, Minn., strip-tiller Bruce Wichmann says that chopping cornstalks in the fall is essential for his strip-till success. If Wichmann falls behind chopping stalks in the fall, he will pay for that in subsequent growing seasons.
“The main thing that works for me is getting 100% of the residue on the ground after corn harvest,” he says. “I need to get the breakdown process started as soon as possible and as completely as possible.
"I have gone back to chopping my cornstalks in the fall. Chopping gets more surface area exposed for the microbes to work on quicker and more complete, as well as reducing snow buildup in the field. Warm, dry soil conditions in the spring for planting and early growth have priority over maintaining plenty of residue on the surface to conserve moisture into August.”
Wichmann uses a 20-foot-wide Alloway flail chopper, which has about 290 “L”-shaped knives on a rotating drum.
“When you drive forward with the flail chopper, the drum rotates backward, lifting the cornstalks up and over the top of the drum,” he says. “The chopper sizes the cornstalks down to about 3 or 4 inches. It also splits the stalks, which exposes the pith and hastens the breakdown.”
Anchor Chopped Stalks
Chopping stalks in the fall is only half of the winning formula for managing cornstalks.
“To be successful in keeping the residue in the field, the freshly chopped stalks cannot be subjected to high winds with dry conditions,” Wichmann says. “Once snow and rain falls on the residue, it settles, it is more strip-tillable and it does not to move as easily."
To aid in anchoring residue, Wichmann uses a Landoll Pulverizer roller after planting in the spring.
“Smooth-drum rollers leave open a window for wind to make residue drifts after the cornstalks have been rolled, and covering up the cleared strips," Wichmann says. "The Pulverizer greatly minimizes that.
"In addition, the Pulverizer gets more soil contact with the residue. Converting the residue to useable nutrients and organic matter sooner is what is beneficial to conservation-tillage practices.”
Wichmann strip-tills both corn and soybeans. He farms 600 acres, comprised mostly of corn, soybeans and spring wheat, along with a small amount of hay for his six horses. Because snow can come early in the fall and fall during May, too, it’s important to get some strip-tilling done in the fall. That’s especially so for wheat-stubble ground.
Wichmann uses an eight-row Dawn Pluribus coulter setup on a Blu-Jet Land Tracker cart.
“The Pluribus units allow me to maintain the deeper soil structure improvements of no-tilling and provide a seed zone that is comparable to conventional till,” he says. “The cart is equipped with tanks to band 10-34-0 and 28% liquid nitrogen.”
Corn Residue Berm
For the 2011 growing season, he will attempt to set up everything for variable-rate nutrient application. The planter is already set up for the banding of liquid starter and micronutrients.
Wichmann plans on setting up the Land Tracker with a second toolbar and coulters. This will enable him to do two separate fertilizer applications in one pass. He plans on using a uniform rate of 28% liquid nitrogen applied on 60-inch centers and variable-rate 10-34-0, side banding with the Pluribus on 30-inch centers
Because the soil and weather throughout the U.S. and Canada vary widely, Wichmann says there is no single surefire approach for strip-tilling that would be relevant for everyone.
“The biggest reason for strip-tilling on my heavy ground is residue management,” he says. “In some areas of the United States, a knife-type system may work. In my opinion, a shank-type unit is something that should be used only in the fall. A coulter system is ideal.
“In reality, the only thing one should be concerned with in the spring is getting good seed-to-soil contact for planting and capturing the radiant energy of the sun in a clear, black strip of soil to start accumulating growing degree units as soon as possible. That is the only thing that is different from no-tilling and strip-till.”
Patience Pays Off
Strip-tilling corn is Wichmann’s top priority.
“Direct-planting corn in my area is a 100%-guaranteed formula to greatly reduced net profit per acre,” he says. “Soybeans are more forgiving, but the advantage goes to soybeans planted into a clear strip vs. those planted into residue.
"It’s all about GDU accumulation in the seed zone and that starts the day the seed goes into the ground.”
Wichmann says that research has shown up to a 12-degree difference between the strip and soil covered by residue in between the rows. In heavy soils, the biggest problem no-tillers face is seed-slot closure and sidewall compaction, he says. But the “potting soil” left by strip-tilling greatly minimizes these problems.
“The biggest lesson I’ve learned from strip-tilling is the need for patience,” Wichmann says. “Balance the forecast of nearby weather and current conditions for when to go into the field in the spring.
"Farm your fields rather than trying to keep up with the neighbors. If I had to put things into a nutshell, that’s what I’d have to say.”
Wichmann also says it’s important that strip-tillers work with an agronomist — whether nearby or far away — who is open to or experienced with conservation tillage. An agronomist with this knowledge can help strip-tillers keep the nutrient side of the process in check.
He says there’s a difference in conventional-tillage agronomy and strip-till agronomy, even though the same soil science applies to both equally.
“Keeping the nutrients in check involves accepting the reduced amount of fertilizer needed when banding vs. full-rate broadcast application,” Wichmann says. “Many people still believe you need all the poundage regardless of the tillage practice used. University data proves otherwise, but it's another step to micromanaging the whole strip-till regime to its maximum potential.”
Determination and perseverance are important factors in making strip-till succeed, he says, but being flexible is the most important thing.
Poorly drained fields are best strip-tilled in the fall and then planted to corn into the “stale” strips in the spring, Wichmann says. By stale strips, he means those strips that built and fertilized in the fall and left to settle until the spring. But this requires a planter set up for no-tilling. Where he farms, there’s generally a window — sometimes small, sometimes wider — that ground is fit to strip-till after spring thaw.
“A farmer might be strip-tilling for bean planting when you don’t have a seed of corn in the ground,” Wichmann says. “In other years, one can plant corn and then move onto beans. And in still other years, direct planting of beans might be the best option.
"Time has shown me that the sooner all strips can be made in the spring for both corn and beans, the more success one will have in producing higher yields. Every year I’ve been strip-tilling, there always was an area that had minimal residue where the beans just flourished over and above the average field conditions where they were no-tilled.”