7 years of strip-till is rewarding Ames, Iowa, farmer Dennis Smith with double-digit yield increases in corn, higher soil-organic matter levels, cooler summer soils and more timely spring planting.
Before he started strip-tilling several years ago, Dennis Smith used to look out in his fields in the spring and see waterways that formed due to ponding rainfall.
But these days, Smith is planting right through those areas because strip-till has boosted soil-organic matter and water-infiltration rates on his Ames, Iowa, farm. This goes along with several other bottom-line benefits he’s seen.
“We can take a lot more rain than we used to,” says Smith, who’s now using his fourth version of Environmental Tillage Systems’ Soil Warrior. “Come fall harvest, if we get rain, we’re able to travel much sooner to harvest.
“Our conventional neighbors have seen us out harvesting and they’ll go out there and the soil is wet and they’re sliding around. It’s just a function of soil structure. It’s been interesting to watch that.”
Smith’s 30-foot-wide, 12-row Soil Warrior, which he purchased last January, comes with interchangeable row units for spring or fall operations, and deep cog wheels that let him place dry fertilizer at various depths throughout the soil profile.
MAKING IT WORK. Ames, Iowa, farmer Dennis Smith started strip-tilling corn 7 years ago and has seen higher yields, better water infiltration and fuel and labor savings as well. “It’s just much easier because we’re not disc ripping and field cultivating. Someone else can have that,” he says.
The machine has a 2,200-gallon tank for liquid fertilizer and a larger dry box than his previous model.
In the fall, for 30-inch corn, Smith uses the Soil Warrior’s “vertical-tillage”-style coulters to fracture the soil and build strips 6 inches wide. As this is done, the machine places phosphorus and potassium up to 10 inches deep, with a majority of the fertilizer applied at 5 to 6 inches below the surface.
In the spring, the row units are switched out with two wavy coulters per row and Smith uses them to re-condition and fluff the strips built the previous fall. Smith usually applies 32% with the spring pass.
Smith says the “spring fluffing” gives him a better seedbed for corn and provides another chance to apply nitrogen before planting.
One decision he made was not to cut fertilizer rates with strip-till. All of his fertility products used to be just broadcast on the surface, but rather than changing rates, he just uses the strip-till system to incorporate them into the root zone so plants can take up the nutrients better.
“Some strip-tillers are after a fertilizer reduction, but my answer to that is, ‘Don’t reduce it.’” he says. “The reward in the end is in the yield increase.”
RTK A Must
Smith uses Ag Leader’s ParaDyme RTK system with Integra monitors to build strips and recondition them, shifting the rows back and forth 15 inches each growing season with the touch of a button.
“If someone asked me, I would tell them not to go to strip-till until they get RTK. If you don’t have it, you’re limiting yourself to a certain degree,” he says. “I can go back and hit the same tramlines again, and shift back and forth in between rows to make the spring pass.
SPRING OUTLOOKING. Strip-tiller Dennis Smith has the coulters on his 30-foot-wide, 12-row ETS Soil Warrior in the spring setup. He plans to strip-till both corn and soybeans this year to fight back against corn rootworms.
Since Smith started strip-tilling, and as he’s worked with ETS, he’s always made two passes. He says ETS studies have found the conditioning pass in the spring is worth 7 to 10 bushels of corn.
“It’s kind of worthwhile because we’re finding the same thing,” he says. “It creates a better seedbed and better seed-to-soil contact.”
Smith suspects that on his farm, nutrient placement under the root zone and better soil health have led to better corn yields. And he doesn’t report having problems with residue levels, even in continuous corn. But he has built some “stalk pusher” cylinders on his planter to keep stalks from shredding tires.
“In my opinion, strip-till is a far-superior system with corn on corn,” he says. “It’s just much easier because we’re not disc ripping and field cultivating. Someone else can have that.”
Smith adds that the Soil Warrior provides him with the flexibility he needs to address fast-changing conditions on his farm.
Last year, he laid down fertilizer for soybeans in 30-inch rows and he’ll be strip-tilling soybeans for the first time after being in continuous corn for 6 years.
“We’re having corn rootworm issues because of Bt failures. We didn’t’ see it coming and it hit us hard in 2012,” Smith says. “The No. 1 defense against that is soybeans.”
Smith says the soil-health benefits of strip-till as a result of tilling only 33% of the field and leaving residue to protect fields, have become very apparent in recent years.
FLEXIBLE MACHINE. Dennis Smith’s 30-foot-wide, 12-row Soil Warrior has an air-bag system, 2,200-gallon tank for liquid fertilizer and a large dry box.
During last year’s drought, field averages for corn of 171 bushels were down to 100 to 120 bushels, depending on the soil types and conditions and if any timely rainfalls occurred.
But overall, he’s watched the level of soil-organic matter increase from 2.5 to 3 when he started strip-tilling to “a lot of 4s and some 5s” popping up in last fall’s soil-test results.
Getting soil to warm up in the spring has been another issue that pushed Smith to turn to strip-till. He tried no-tilling for 2 or 3 years, but couldn’t get soils to warm up fast enough in the spring to meet his planting timeline.
“With our strips, I’ve thrown down soil probes in the spring and there are some days where it’s 7 to 10 degrees warmer in the seed zone than off the zone,” Smith says. “Then, last summer when we were in extreme heat, I had gone to Iowa State University’s Web site to find soil temps in July and they were pushing into the 90s or 100 degrees.
“Then I took soil probes and set them in our corn residue, and the soil was in the mid-70s. So strip-till works in cold and heat.”
Smith says it’s undeniable that he’s burning much less fuel. His spring pass with the Soil Warrior runs at about 12 to 14 mph with the 30-foot machine, covering 45 to 50 acres an hour.
“That doesn’t take much fuel in spring and the next pass is with the planter,” he says. “I would rather take a 30-foot machine across the field than a five-shank ripper, and there are substantial fuel savings. And machinery-cost wise, you can take a new ripper and field cultivator and have nearly the same cost as this Soil Warrior.”
Taking Another Step
RTK HELPS. Dennis Smith uses Ag Leader’s ParaDyme auto-steer system with Integra monitors to build strips 6 inches wide each fall, alternating them 15 inches each year.
Even as organic matter has nearly doubled in some fields, Smith wants to take it a step further by working with cover crops to increase organic levels more.
About 3 or 4 years ago, after he harvested some early corn, Smith used his Soil Warrior to apply fertilizer mixed with oats. The oats germinated and reached 3 inches tall, but a wet spring the following year made it impossible to get reliable results from the experiment.
“Since then, we just haven’t had another fall to get out and get that germination. The past two falls were dry and that doesn’t help get a cover-crop established,” he says. “This fall, after harvesting soybeans, we’re going to have this machine running in a soybean field putting down cover crops such as oats, winter peas or radishes, or a combination of them, so we can get a better run at it.”
Making It Work
Smith says trying strip-till for the first time can be quite an adjustment for farmers. He does some custom strip-till work for another farmer in his area, and some other farmers he knows are trying strip-till and dealing with their share of frustrations.
"Some of them trying to move stalks with trash whippers and loosening the stalks, and then the wind comes in after they plant corn and the loosened stalks fall over into the corn rows and affect germination," Smith says. "Some of them will go in the spring with a shank, when soils are too wet, and smear the sidewalls, which can cause germination and root-development issues."
There’s a temptation for farmers to want instant gratification, he adds.
“It takes 3 to 5 years to get your soil turned over into proper structure,” Smith says. “For one of my customers, it’s been frustrating waiting, but we’re in our third year of strip-till and he’s happier with it now.
“It’s a management change, if you will. It works if you want it to work. If you stick with it and do it right, it’s as good or better than anything else out there.”