Illinois no-till farmer Roger Kennell will never forget the spring of 1992. It was cool and wet, and he was forced to plant corn in less than ideal conditions just to get his crop in on time. A dry spell followed. And without any rain to soften the soil, the seed channel hardened like concrete, preventing nodal roots from developing.

"We had corn plants falling over and dying, literally," Kennell recalls of the year that cost him a significant amount in yield. That fall a representative from local equipment maker Case-DMI visited Kennell and asked him if he wanted to try a prototype machine designed to prevent such problems from happening again on his no-till corn acres. "That's when I started strip tilling," Kennell says.

The machine was basically an anhydrous toolbar equipped with regular anhydrous knives and 14-in. closing discs. It was designed to till a narrow strip of soil, about 8 in. wide, in the fall, into which Kennell could plant his corn seed the following spring. Behind the toolbar he pulled a dry fertilizer cart and an anhydrous tank to band nitrogen, potassium and phosphorous all in one pass while tilling the strips.

"I was real pleased with what I saw," Kennell says. "And we're getting better yields than with straight no till."

Kennell is part of a growing wave of no-till corn farmers who are buying strip-till equipment to combat low yields, inconsistent stands and slow early growth on poorly drained soils, especially in cool wet springs. The number of strip-till acres is still quite small - a fraction of the 16% of Midwest acres planted to no-till corn, according to Dan Towery, natural resources specialist with the Conservation Technology Information Center (CTIC).

However, experts expect that number to boom as more equipment becomes available, more dealers and co-ops step up to offer custom services, and more farmers look to combine the warming and drying benefits of tillage with the soil conservation benefits of no till.

Fools the corn

The concept of strip till is simple. By tilling a small strip you are putting more air in the soil, which makes the soil dry faster than in a conventional no-till system. But because only a third of the row width is being tilled, the system is still considered no till.

"It fools the corn into thinking it was field cultivated," says John Wolf, director of marketing for Progressive Farm Products, which makes strip-till equipment.

The result? Earlier planting, in extreme cases up to three weeks compared to a no-till system, less time to work the ground compared to conventional tillage, better stands, better early growth, and often higher yields in those years when weather conditions are adverse, says CTIC's Towery.

Yield data collected by universities in Ohio, Indiana, Illinois, Minnesota and Iowa show that strip till holds up to a 10% advantage over conventional no till, depending on soil, year and residue cover. In addition, it usually yields within 3% of conventional tillage, which uses a chisel plow in fall followed by spring secondary tillage, according to Dr. Tony Vyn, cropping systems agronomist at Purdue University. "So from a profitability standpoint, we are probably able to do strip tillage with a greater return on investment than conventional till," Vyn says.

Strip-till essentials

Until recently, few companies made strip-till equipment. And those that did all but sold out in the last four years.

However, now more companies are stepping into the game in response to rising demand. And they are offering fully equipped rigs as opposed to just add-ons that farmers would have to retrofit themselves, according to Frank Lessiter, editor and publisher of No-Till Farmer. "A lot of the equipment up until the last year or so were homemade modifications," he says. "Now you can buy complete strip-till rigs."

These rigs typically come in 6-, 8-, 12- and 16-row configurations, sized to match the width of your planter, and come with or without the ability to apply fertilizer at the same time you are tilling the strips.

Regardless of whether you buy a complete rig or put together your own, there are basically four essential components to any strip-till unit, according to Purdue's Vyn.

The first essential is a heavy-duty toolbar equipped with row markers that will allow you to lay out the strips in such a way that you can match up your planter in the spring.

Second is a coulter to cut through residue on the soil surface. Some recently developed strip-tillage tools also have row cleaners in front of the coulters.

Third is an anhydrous-type shank and knife assembly of moderate aggressiveness that is capable of loosening soil to depths from 4 to 8 in. Vyn says the shank should be capable of being equipped with a fertilizer tube assembly to allow for deep banding of phosphorous, potassium and anhydrous at the same time you are tilling the strips. This results in a greater economic return because you are accomplishing two operations (tillage and fertilizer placement) in one pass.

"Our rule of thumb is to run [the knives] 6__1/2 in. deep at 6__1/2 mph to get good fracturing of the soil," says Progressive's Wolf.

Finally, you'll need covering discs (also called disc sealers or disc closers) mounted immediately behind the shank to capture the soil being displaced by the knife and put it back in the strip to build a 3- to 4-in.-high berm on which to plant the following spring. The berm mellows to 2 in. or less by spring.

Can you afford?

The price of a strip-till machine starts at $5,000 to $7,000 for a 12-row basic setup without nutrient placement and goes up to $50,000, depending on how it's equipped.

For example, Kennell paid around $50,000 list price for his latest rig, which he bought from Case-DMI. It consists of a 3250 toolbar in a 12-row narrow (30-in.) configuration. The toolbar is attached to a NP9000 dry fertilizer caddy with a 9,000-lb. tank, auger meters and an air delivery system to apply potash and potassium. Behind the caddy is an anhydrous bar for banding anhydrous.

The toolbar is equipped with Mole knives as opposed to regular anhydrous knives, which Kennell says "heave" the ground rather than just opening it. "I wouldn't go back to regular knives if you paid me," Kennell says. "There's a bit more soil action so you can build a better berm." For more information about Mole knives, contact Hi-Pro Mfg., Dept. FIN, Rt. 24 W., Watseka, IL 60970, 815/432-5271.

Kennell also switched from 14- to 18-in. disc closers, which he says are needed to contain the additional soil kicked up by the Mole knives. The closers are non-sharpened to prevent them from cutting a groove on the side of the berm, which could cause it to wash out.

Kennell strip tills around 480 acres of corn and custom farms another 450, also strip tilled. Over the years he has compared conventional no till, strip till without nutrient placement and strip till with nutrient placement. Based on a five-year average, Kennell reports a 6-bu./acre advantage in strip till without nutrient placement and a 10-bu./acre advantage in strip till with nutrient placement over no till.

Factoring in the yield differences along with equipment costs, labor and other input expenses, he figures his profit per acre for strip till to be $38.84 with nutrient placement (N, P and K banded in the strip) and $27.92 without nutrient placement (broadcast P and K). This compares to $24.66 for no till (broadcast P and K and sidedress N) and $22.50 for conventional.

Progressive's Wolf says the easiest and cheapest way to get started is to use an existing anhydrous type toolbar and add a set of row markers. "We've had a lot of people start out like that," Wolf says. "Usually they do that for a couple of years and then decide to get more advanced and get into some fertilizer placement along with doing the strips."

If you do decide to retrofit an existing bar, Cary Sizelove, representative of Case-DMI, says to make sure the toolbar is made of heavy-duty 4- x 6-in. tubing instead of 4- x 4-in., which is needed to withstand the strength of the higher trip force shanks being built today.

For example, Case-DMI makes a heavy-duty, spring-bundle shank with a 850-lb. trip force ($120/shank) and just this year it is coming out with a new High Clearance Shank with 1,150-lb. trip force and 7__1/2-in. trip height ($290/shank). Contact Case-DMI, Dept. FIN, Box 65, Goodfield, IL 61742-0065, 309/965-2233. Sizelove says the shank you buy should have a starting trip force of at least 800 lbs. to ensure the knife stays in the ground and cuts at a constant depth so that you end up with a uniform berm for planting.

Custom an option

At a time when commodity prices are low, many farmers will not have the money to invest in a different tillage system. For that reason, more fertilizer dealers, co-ops and farmers who already own their own strip-till rigs are offering to rent out their equipment or do the work for you.

Costs can range anywhere from $9/acre for just equipment usage up to $14/acre to have someone do the work for you and furnish the tillage rig, tractor and fuel.

Although this new custom trend may be a good way to test strip-till equipment, some large-acreage farmers may be able to justify buying their own equipment. However, Case-DMI's Sizelove says farmers probably need at least 700 acres of corn. "And then you probably also need to do a little custom application," Sizelove says.

For example, Mark Freed, a no tiller from Lexington, IL, who farms 1,000 acres of corn in addition to doing custom work, says he was able to pay for his $40,000 rig in a single season. His fields were showing signs of sidewall compaction due to wetter, cooler soils before he switched from conventional no till to strip till in the late 1980s.

The compaction was costing him 5 to 10 bu./acre in those years when there wasn't rain for one to three weeks after planting to soften his silty clay-loam soil. With strip till, Freed has been able to recapture that yield loss.

Freed owns a 6200 Dual Placement Unit built by Progressive Farm Equipment, which, like Kennell's, can apply dry P and K along with anhydrous ammonia all in one pass. Contact Progressive Farm Products, Dept. FIN, Rt. 1, Box 17, Hudson, IL 61748, 309/454-1564.

Both DMI and Progressive also sell rigs that can apply liquid P and K along with anhydrous ammonia.

The downside of strips

Even though strip till works well, farmers still have to look at the possible downside, cautions CTIC's Towery. For example, he says your toolbar and planter have to match up exactly, and it takes a knack to see the strip. "Sometimes it takes a half of a day to get on it," he says.

Another potential drawback is that you never know when the window for getting your strips made will close in the fall. Anhydrous ammonia is the limiting factor. If it is applied too early in the fall, it could leach or volatilize. If you wait too long, the ground could freeze up, preventing application. To avoid this problem, some farmers are making their strips in the spring before planting instead of in the heat of harvest.

Another disadvantage with strip till may be size. Until recently, a 16-row was the largest strip-till toolbar you could buy, and you would have to special order it. However, just this year, Progressive has come out with a 60-ft., 24-row toolbar, model 7200, to meet the needs of farmers with 24-row planters.

Finally, strip tilling requires more horsepower than no till due to the depth of tillage for each strip and the weight and rolling resistance of the fertilizer tanks, according to Dr. Gyles Randall, soil scientist with the University of Minnesota's Southern Research and Outreach Center. "If you are pulling an ammonia tank or dry fertilizer caddy to supply N, P and K, between 20 and 30 hp/knife is needed," Randall says. However, horsepower requirements can vary by soil conditions, and in most areas, 12 to 15 hp/shank is oftentimes sufficient, according to Wolf and Sizelove.

Despite these challenges, Freed and no-till farmer Kennell say they are glad they switched tillage systems. Says Kennell, "It has allowed me to accomplish a lot of the objectives I had for no till yet get my yields back up to where I wanted them to be to be competitive."

For more information, order No-Till Farmer's 24-page special report on strip till. Cost is $9.95. Contact Lessiter Publications Inc., Dept. FIN, Box 624, Brookfield, WI 53008-0624, 262/782-4480.