Till or No-till? Do Both With Strip-till

The field practice may speed crop development, reduce disease potential, and save time, fuel, and moisture.

By Tracy Sayler

Strip-till is a field practice that is getting a closer look by some crop producers and crop scientists in the region, since it combines the benefits of no-till (savings in time, moisture, topsoil and fuel use) and tillage (warmer soil in the spring helping row crops get off to a faster start, reduced soil compaction, and reduced disease potential). 

The advantages of strip-till, which might be described as a cross between no-till and ridge-till, are best realized when it’s done in the fall, although it can also be done before planting.

A strip tiller deep bands fertilizer and creates a furrow for seeding sunflower, corn, or soybeans, allowing savings in time, moisture and fuel use.

A strip tiller is used to place fertilizer and create tilled furrows for seeding. Knives on the strip tiller (most commonly set at a 30” spacing) prepare the seedbed and place fertilizer simultaneously. Dry or liquid fertilizer may be applied, depending on the setup of a particular unit. Fertilizer can be placed “2x2,” with seed 2” below the soil and fertilizer 2” below the seed. Anhydrous mole knives or other knives may be used. The knives used in combination with coulters on the unit cut through field residue leaving thin furrows or tilled strips down the length of a field, about 6 to 10 inches wide and 6 to 8 inches deep, depending on the knives being used.

About two-thirds of the row width remains untilled, covered with residue to benefit moisture retention and microbial activity that builds organic matter. In the spring, corn, soybeans, sunflower, or another row crop can be seeded into the strips with a row crop planter.

“The seed thinks it’s in a tilled area, but in fact, it really is a form of no-till,” says Wayne Pedersen, research plant pathologist, University of Illinois at Urbana-Champaign. 

Pedersen has been studying strip-till for five years. “Why is a plant pathologist doing this? I think part of it is the machinery junky in me,” says the Grandin, ND native. “But more than anything, I’ve tried to figure out ways to improve stands in no-till corn, and it’s always been a disease problem, particularly a fungus called Pythium, which likes cold wet soils, and often infects the seed before it emerges.  If we can get that soil temperature above 55 degrees and drier, the fungus can’t keep up and the seedling will actually grow away from it.”

The soil in a strip-till system is indeed warmer and drier at planting than no-till soil, which reduces losses associated with Pythium seed root rot, says Pedersen. In a three-year study he conducted from 1996-98, corn yields using strip-till were comparable to mulch-till, and about 25 bu/ac better than no-till.

University of Minnesota assistant soil scientist Jeff Vetsch says the Minnesota Experiment Station has been testing strip-till at four locations: Waseca, Morris, Lamberton, and Rochester, Minn. Most of the testing consists of strip-tilling soybean stubble in the fall, then planting corn in the narrow tilled rows the following spring. “From an agronomic standpoint, it looks like a pretty good system. Yields have been as good as conservation or mulch tillage, just a few bushels less than conventional tillage, and better than no-till, virtually every year we’ve had it here at the station,” says Vetsch, who’s based at the Southern Research and Outreach Center in Waseca. However, differences among the tillage systems are less noticeable when spring temperatures are warmer, he notes.

“Strip-till has potential to be a system that could work well for farmers who wish to reduce trips across the field and cut input costs. It’s one-pass planting in the spring with no primary tillage, and you still have a high-residue soil environment,” says Vetsch.

Although strip-till is a system that is geared more for corn, it may work for other row crops too. James Kurle, U of M research plant pathologist, is testing the effect of strip-till on soybeans and dry edible beans in studies at Waseca and Staples, Minn.

“Strip-till may help alleviate soil compaction that I believe is causing rooting problems in many parts of the state,” says Kurle.  “Compaction interferes with drainage, and plants in saturated soil can’t get nutrients as well and are more susceptible to disease. I think root diseases are more common than people realize, contributing to early season stress. There’s a connection with these factors, with one problem causing another. I think strip-till would allow better infiltration of moisture and shorten saturation periods, improve drainage and reduce root rot problems.”

Producers Trying Strip-till
Strip-till actually is not a new field practice; it has been used in the Cornbelt for over a decade. Adoption of the practice has now moved northward, along with the increased production of corn and other row crops. Vetsch believes it’s catching on too because people understand the concept better.

“No-till corn is not thought of well in northern areas of the Cornbelt, and so I think people thought the two practices were too similar. But now the adoption of strip-till is increasing, and I think part of it is due to greater producer awareness from University research, farm press, and agribusiness companies that have taken an interest in it,” Vetsch says.

In North Dakota, for example, Monsanto began leasing an 8-row, strip-till unit for its retailers to provide for producer customers. Rental cost to producers may vary, but it’s about $3/acre, or in some cases, free, if producers buy seed from Dekalb or Asgrow, both of which are owned by Monsanto. Providing the unit partly promotes a sound field practice, but it also could result in increased sales: Strip-till may help Monsanto sell Roundup Ready seed, and Roundup for pre-plant burndown treatments.

The tractor requirement to pull a strip tiller is a minimum of 160 horsepower with 3 hydraulic remotes, and capable of a fourth hose to relieve back pressure from the air delivery fan.  This hose runs back to the tractor hydraulic reservoir, similar to most air seeding systems.

Ag Systems based in Hutchinson, MN, manufactures the strip tillers. Company vice president Paul Lenz says strip till is more commonplace in growing regions further south, and used with success in tobacco and cotton. The concept has been working its way north, however, partly because farms are getting larger—and producers are looking for ways to cover more acres more efficiently.

Each strip tiller (which Lenz refers to officially as the “Thru-Flow strip-till deep bander”) is custom finished, and fitted with different blades or knives depending on user needs. While the company makes 8 and 12-row units, Lenz’ company has the capacity to make a 16-row unit, he says.

Ted Chizek, a distributor of the strip tillers based in Casselton, ND, says cost of a new unit can range between $18,000 and $28,000, depending on unit size and attachments. Lease and renting options are available.

Byron Richard hoped snow would hold off long enough for him to try strip-tilling last fall, to save on seedbed preparation time this spring. That didn’t happen, but he plans to try it anyway this spring on his farm near Belfield, ND.  Richard, who also has a seed and herbicide business, figures strip-till may benefit his corn, and give him better odds at trying confection sunflower.

“If we can get in the field sooner and get quicker emergence, maybe we can plant a later-maturing hybrid and get better yield, or plant confection sunflower, and if you want to go with that, you need more growing season,” says Richard. In his growing area where dryness can hamper good confection yields, getting a confection sunflower crop off to a faster start would also mean a quicker canopy for better moisture retention, and thus greater potential for higher quality and higher test weight.

Richard solid seeds sunflower, so he’ll need to go back to rows in fields where he tries strip-tilling this spring. “We’ll have to see a yield increase to justify the row crop planting,” he says.

Christof Just, who farms near Berlin, ND, strip-tilled 80 acres of wheat stubble last fall. “It probably wasn’t the most ideal conditions to get the best feel for the machine. The field’s a bit rocky and it started to rain so I did have some problems with rocks bunching up with the wet soil,” says Just, who is also an agronomist with a company in nearby LaMoure, ND. “But I can see it working well, especially Roundup Ready corn. You can put fertilizer down in the fall in ridges and then the following spring put in starter fertilizer or just seed, and you still have the residue between the rows. We’ll see how it does after the corn is planted.”

Pedersen of the University of Illinois has family members who farm near Valley City, ND. “I almost brought our strip-till unit up there last fall. They want to try it in a barley or wheat field and follow with soybeans or sunflower,” he says.

Perfection is tough to ask from any tillage system, including strip-till. Rain (or early snow) can prevent strips from being tilled in the fall. And at seeding, you’ll need to stay alert to keep the planter within the strips. Still, Pedersen believes strip-till is a practice that has merit, particularly in colder, black soils that tend to warm slowly.

“I still think no-till works as well on lighter, drier soils. If you can make no-till work, environmentally and economically, it’s still the best system, in my opinion,” he says. “But a lot of growers haven’t been able to make it work, because of disease management. So strip-till is a really good alternative.”

A strip tiller is used to place fertilizer and create tilled furrows for seeding. Knives on the strip tiller (most commonly set at a 30” spacing) prepare the seedbed and place fertilizer simultaneously. About two-thirds of the row width remains untilled, covered with residue to benefit moisture retention and microbial activity that builds organic matter.