By Dan Zinkand
After 9 years of using the Rawson 3-coulter zone-till system to plant corn, Jim Millett and his father, Joe, of Bailey, Mich., switched to strip-till in 1997 and have stuck with the system ever since.
Michigan farmer Jim Millett has been spring strip-tilling corn since 1997, after using the Rawson "zone-till" system for about 9 years.
The Milletts, who grow corn, soybeans, alfalfa, oats and winter wheat and have dairy cows, tried two different strip-till machines before choosing a Progressive strip-till rig.
"The first strip-till rig didn't have a rock trip and when a mole knife hit a rock, we sheared off a lot of bolts," Jim Millett recalls. "We demonstrated another strip-till rig, but the deep shanks caused too much soil disturbance. And then we demoed the Progressive unit, which is what we've been using for 14 years."
Tillage System Changes
Before the Milletts started using the Rawson system in 1988, they mostly chisel-plowed and then disced fields before planting corn.
The Rawson zone-till system worked well, except when the fields were wet and mud balled up on the gauge wheels on the planter, Millett says. So they decided to strip-till when the machines became available.
The Milletts strip-till in the spring because it's usually too late in the year to do so when they finish harvest in the fall.
"We broadcast 4,000 gallons per acre of liquid dairy manure on their corn-silage ground, then no-till winter wheat," Millett says. "Some fields with soybean stubble receive 4,000 gallons of manure per acre before we strip till. We apply phosphate, potash and lime in the spring."
The Milletts take a nitrogen credit of 1 unit per bushel of soybeans for the following year's crop of corn. This usually works out to a credit of 40 units.
Other than the dairy manure, all of the fertilizer for the corn is applied at planting. The Milletts apply 35 gallons of 28% liquid nitrogen, which contains 3% sulfur and 5 gallons per acre of 9-23-3 with some micronutrients.
Millett likes the rock-trip feature on his Progressive strip-till rig, something that the first strip-till rig he demoed didn't have.
Millett typically strip-tills about 2 to 3 weeks before planting corn. The Progressive strip-till machine makes a strip about 7 inches wide and 6 inches deep.
The Deere tractor the Milletts use to pull the 8-row Progressive strip-till rig with 30-inch spacings has about 200 horsepower, which is more than enough power than needed to pull the strip-till rig, he says. While they use GPS when spraying fields, they don't for strip-tilling. Millett says he can see where the strips are when planting corn.
Their planter is a Kinze 8-row on 30-inch spacings with no-till coulters, Keeton seed firmers and cast-iron closing wheels, but no row cleaners, which Millett says isn't necessary for strip-till on his farm.
Like many strip-tillers, Millett is sold on the soil warm-up that occurs in the tilled soil.
"I took a soil thermometer one spring at planting time and measured the temperature in the soil where we planted corn, and in the untilled soil next to the strips," he says. "The soil in the strip was 8 degrees warmer than between the strips, where the residue was undisturbed."
Fall weed control is important to making spring strip-till work, Millett says.
"In the fall, we apply Autumn and 2,4-D on soybean stubble that we plant to corn the following spring, and Canopy EX with 2,4-D on corn ground that we will plant to soybeans," he says. "It's important to kill the winter annuals in the fall. If they're in the fields in the spring, the weeds make a mat and strip-tilling corn into that doesn't work very well. And Autumn and Canopy have residual."
Soil And Yields Improve
After 15 years of strip-tilling, the Millets have virtually eliminated tillage on their farm.
"If we put in alfalfa, then we do a light discing to level the field, but other than that, we do very little tillage," Jim Millett says. "The corn is all strip-tilled and the soybeans are almost all no-tilled. We use just a half-gallon of diesel to strip-till an acre of corn and another half gallon to plant it."
With about 200 horsepower, this Deere tractor has more than enough power to pull the 8-row Progressive strip-till rig with 30-inch spacings, Millett says.
There's just one other farmer in the area who strip-tills, but during the winter, three farmers stopped by to talk with the Milletts about strip-tilling corn.
"We feel that with strip-till, we are as competitive as any tillage system," Millett says. "When we chiseled the clay hills on our farm, the soil would slab up and then we would have to beat it back down with more tillage. It would be 3 weeks after we planted the field before the corn came up. With strip-till, the whole field of corn comes up even."
Millett says it's hard to tell how much of the 40% increase in yields on his farm during the past 15 years is due to strip-till itself or improvements in corn genetics. He suspects genetics play a major role, "but for us, we use a systems approach and so yield is not the result of just one thing."
The Milletts try to minimize compaction in their trips across the field, running equipment as light as possible with larger tires that provide flotation.
"We don't have ballast weights on the tractor. We don't need them," he says. "Running everything as light as possible is the opposite of what you do with tillage. We have one tracked tractor, but don't have the combine on tracks."
Soil Tilth Improves
After switching to zone-tillage in 1988 and strip-tillage in 1997, Millett has watched the changes in the soil that come from eliminating the full-width tillage they once did.
"It takes about 3 years for the earthworms to show up in the fields," he says. "Today, there are significant earthworm holes in our fields. The tops of our hills aren't as hard as they once were and the low spots in the fields aren't as wet.
"We still need to tile, but after the rain, the water doesn't stand as long as it once did."