Strip-till corn yields often are equal to or better than yields from corn grown under other common tillage systems, according to university research conducted in several Midwestern states. This translates into economic and environmental rewards, say experts who've examined the practice.
“Strip-till works out well for corn in a corn-soybean rotation with no-till soybeans in both southeast and south-central Minnesota,” says Gyles Randall, a soil scientist with the University of Minnesota Southern Research and Outreach Center, Waseca, MN. “From a time and cost perspective, the economics typically come down in its favor.”
Strip-tillage creates cultivated strips about 6-8 in. wide while also leaving a large quantity of crop residue undisturbed between strips. The system, which fits under the USDA's definition of no-till, helps provide a seedbed of loosened soil that warms and dries soils quicker than fields left covered completely with crop residue until planting.
“From a soil and nutrient perspective, strip-till is a good system that leaves lots of residue, with less risk of nutrient runoff and other environmental concerns,” says Randall, who has done strip-tillage research since the fall of 1996. “In terms of yield, it's no better than chisel plow or full-width tillage, but it is better than no-till corn following soybeans.”
Savings in soil, labor, fuel and machinery are typically the top attractions to the practice, compared to conventional tillage systems, points out Randall. “Yet, the logistics of the operation are such that you need RTK (real-time kinetic) auto-guidance or someone very competent running the equipment,” he adds. “You really need a high level of management for this to work.”
Management is key to strip-till's success, agrees Jim Gerwing, South Dakota State University Extension soils specialist. “It's hard to keep on the strip — unless all your fields are big, square, flat fields,” he points out. “The end rows and corners are especially difficult to stay on, and although RTK guidance systems do a good job, not too many farmers have them because they are extremely expensive.”
Gerwing agrees with Randall that a strip-till system generally offers no significant yield advantage compared to a full-width tillage system, yet offers plenty of economic benefits. “Some years strip-till will increase yields and other years it won't,” he says. “However, it can save you a lot of money in fuel,fertilizer, trips over the fields and by a reliance on less horsepower.”
Strip-tillage typically fits best when planting corn into soybean or wheat stubble, says Gerwing. “Corn on corn is a very hard system to manage with strip-till because of the excessive crop residue,” he adds. “Quite a few corn stalks are baled in this country where corn on corn is grown to take care of the residue.”
Strip-till is also a tillage system that fits best between the heavier, wetter soils in eastern South Dakota, which respond well to full-width tillage, and the drier, lighter soils in the western part of the state that do well in a no-till system, says Gerwing. “The tillage strip alone is certainly beneficial in eastern South Dakota to help warm up soils for earlier planting,” he says. “The fall-applied fertilizer in the strips almost acts as a starter fertilizer in the spring. Unlike no-till, you don't have to worry about volatilization losses from urea fertilizer, because you're not broadcasting it on the soil surface.”
The environmental benefits from strip-till are clearly an advantage to the practice, emphasizes Gerwing. In some areas, farmers may also qualify for conservation payments from the Natural Resources Conservation Service (NRCS) for adopting the practice.
“It will definitely help with erosion control and where no-till doesn't work well,” he says. “It's also a good way to get phosphorus below the soil surface where it's needed, which is better for water quality.”
However, strip-till becomes increasingly difficult with slopes over 4%, says Bob Frazee, University of Illinois Extension natural resources educator. “For strip-till, you'll first want to have fairly level ground,” he says. “Also, if there is too much contouring, it's more difficult to maintain the planter on top of the row.”
Despite the system's limitations, Frazee says strip-tillage is being adopted rapidly in a large portion of Illinois. “A lot of Illinois farmers are switching from mulch-tillage or minimum-tillage systems to strip-till and selling their unnecessary equipment,” he says. “We're definitely seeing an increased interest in strip-till here in the northern three-quarters of the state. Most of the strip-till was being done initially in central or east-central Illinois.”
Several Illinois soil and water districts are currently renting strip-till systems to farmers who want to try the practice for the first time, says Frazee. “The large-acreage farmers are buying RTK auto-steer systems so that they can plant the seed directly into the same rows each year,” he adds. “However, most of our producers are using strip-till without auto-steer.”
The University of Illinois shows that strip-till is comparable or better to the chisel plowing or deep-ripping systems that are typical around the Champaign-Urbana area, says Frazee. “In fact, the four-year average yield shows virtually no yield difference between no-till, mulch-till or strip-till over several locations in the state,” he adds.
Corn On Corn
Some Illinois farmers are also strip-tilling successfully in corn-on-corn acres, says Bob Frazee, University of Illinois Extension natural resources educator. “Corn on corn with strip-till will likely increase your nitrogen requirements,” he cautions. “You'll also need to have a sharp coulter in front of your anhydrous applicator to cut through the residue.”
Strip-tilling corn on corn can be more profitable than strip-tilling corn after soybeans, if the residue is managed successfully enough to maintain yields, says Steve Hawthorne, who has practiced strip-till for seven years near Gibson City, IL.
“I've done a lot of strip-till on corn on corn, and I'm more enthused about that than corn on beans,” says Hawthorne. We can save at least two passes — and one of them is a high-horsepower operation.”
Before switching to strip-till, Hawthorne had operated a chisel plow in the fall and followed with a fall application of anhydrous ammonia and two passes with a field cultivator in the spring when planting corn after corn. “Now I don't have to line up labor in the spring to work the ground or in the fall to chisel stalks,” he says. “In comparison, in corn after soybeans, the only savings in field work is maybe one less cultivation.”
In the past, Hawthorne has used a DMI anhydrous toolbar on a three-point caddy with a regular mole knife. He has also used the larger-size cover disks (18 in. vs. 14 in.) with a smooth edge to cut through residue better and had modified the toolbar markers so that he could see the mark better.
When planting corn after corn, Hawthorne strip-tilled between the old corn stalk rows to avoid trouble with root balls when planting corn after corn. However, this past fall he began using an RTK auto-guidance system to avoid marker problems in the fall and to plant more precisely over the strip in the spring.
Fertilizer management is particularly important for Hawthorne now, because he farms in a Conservation Security Program (CSP) watershed and receives incentive payments for practicing conservation tillage and ensuring fertilizers are applied with the least likelihood of degrading the area's water quality.
“Strip-till corn and no-till beans is what helped get me into the CSP,” says Hawthorne. “But the amount of payment that I receive largely depends on the enhancements I make that are related to my fertility program.”