Growers are learning there’s no one best way to strip-till. “Strip-tillage means different things to different people,” points out Mark Hanna, Extension ag engineer at Iowa State University (ISU). “It’s attractive to a lot of farmers for various reasons.”

In its early days, strip-till equipment was patterned after anhydrous-ammonia applicators, but has evolved to more iron, heavier toolbars and often, down-pressure springs he says.

“While strip-till is not a new practice,” says Liz Stahl, Extension educator, University of Minnesota, “It brings together the best of both worlds: the benefits of tillage in the crop row and the benefits of reduced tillage between crop rows.”

Its benefits include warmer soil for earlier planting, fuel and labor savings; nutrients placed where they’re needed; residue management; and often, higher yields.

In the days of the moldboard plow, a straight furrow was a badge of honor among neighbors. Today’s strip-tillers are no exception. With attachments to place nutrients near the seed row, many growers are now switching to GPS auto-steer so planters match previously laid A-B lines and achieve maximize yields from reduced fertilizer input.

“Previously we did not have RTK (real-time kinematic) on our planter tractor,” says Tom Muller, Windom, MN, who’s been strip-tilling corn since 1994. “Since we bought it, it’s exceeded our expectations. It even worked on side hills, compensating enough to keep the planter dead on.”

Muller, who farms with his brother, plants up to 2,800 acres in a 50-50 corn and bean rotation. Since 2004, he’s contracted with his local co-op to install strips in the fall with a 16-row custom machine. Muller uses urea in his strips instead of anhydrous ammonia to reduce cost. He places needed nitrogen, phosphorus and potassium (N, P, K) in the strip in the fall about 8 in. deep. “It’s important to get that fertilizer in,” he adds.

Overall, he sees strip-till as a residue-management system for the cool black soils in southwestern Minnesota. “We need that black strip to warm up for planting and germination.”

Dick Wolkowski, Extension soil scientist, University of Wisconsin, notes one of the benefits of strip-till is more efficient use of costly nutrients, but soil tests are as important as with other tillage approaches.

“In Wisconsin there’s not as much deep banding of fertilizer,” he says. “A lot of our soils are testing high in P because we have a significant manure history in a lot of fields.” He notes the statewide P average is just over 50 ppm.

Wolkowski urges growers to follow soil tests and match applications to equipment setup and planting. Wisconsin research finds that special attention should be paid to K management in no-till and strip-till.

In one heavy 2008 rainfall, where 15-18 in. fell in eight days, he says reduced tillage saved a lot of soil.

 “Our biggest benefit with strip-till is labor savings,” says Ken Herschleb, Arlington, WI. “We’re running about 2,000 acres with two people, feeding cattle and everything. Just strip and plant…that’s it.”

Making changes

Herschleb has been strip-tilling for eight years. He changed from chisel plowing to strip-till in a CCCS rotation.

He’s made significant changes – purchasing a special Red Ball machine to build strips in the fall. Previously, he tilled and planted in the spring in a single operation with a special planter, but changed that to a 12-row planter using GPS auto-steer to match his fall equipment.

“With fall strips we get a warmer and drier seedbed in the spring,” he says. “That adds early season vigor to our corn plants. Our yields have been going up every year, but it’s hard to quantify whether that’s tillage or just improvements in new hybrids.”

He applies no fertilizer in the fall, and applies N with the planter at a half rate, placing it about 4 in. on both sides of the seed row. Then, he comes back and sidedresses the other half of N, when corn is about 5 in. high.

“If we need any P and K, we have that broadcast by our local co-op,” he says. In the future, he’s considering applying P and K into the fall strips.

Strip-till is not just catching on with large acreages. Fred Abels of Holland, IA, set up a six-row strip-till machine for spring use for watershed protection with two goals: light tillage and precise fertilizer placement. The cost was about $1,000/row. “We used a Case/IH planter bar and mounted a row of Kinze dry-fertilizer boxes on the front and a second row of John Deere dry boxes near the rear,” explains Abels. (See http://tinyurl.com/striptill for more on Abels’ strip-till equipment.)

The first row of boxes drops a dry P and K mix about 4 in. beside the row, which is then incorporated by the anhydrous-ammonia knives. The second set of boxes feeds the same mix into the knives for distribution 3 in. deep. Yetter row openers and a simple system of three coulters/row prepare the seedbed in the strip. ISU’s Extension Ag Engineer Hanna helped Abels design the equipment setup.

Anhydrous ammonia is applied in the same pass, about 4 in. from the row on opposite side, with a toolbar hitch pulling the tank. Abels installs strips in early spring, then plants into them about a week or two later using row markers as guides. The entire operation is done without GPS.

After three years of use, Abels reports he’s getting consistent germination for a more even stand. “The strip leaves the soil very nice, and doesn’t leave a ridge,” he says. Also, by applying fertilizer right before the crop uses it, he eliminates potential nutrient leaching.

“The 2008 growing season was the best corn I ever had,” he says. “My yields were stuck at 150-160 for about five years. The previous year, the on-farm average was 185, and that’s non-GMO corn.”

Replanting is a headache, but RTK auto-steer systems in strip-till programs help growers turn this lemon into lemonade.

One Iowa grower reports he replanted directly over his previous A-B lines, and the new corn plants captured most of the previously applied fertilizer. Without RTK on both his fall strip-till machine and planter, he wouldn’t have been able to match the rows, and would have the mess of reworking the entire field. 

December 2010