Published May 27, 2011 | By admin
By Dan Zinkand, Strip Till Farmer
After 15 years of ridge-tilling, Ulysses, Kan., farmer Larry Smith switched to strip-tilling 4 years ago and finds the practice helps him compensate for environmental factors he can’t control – chiefly, sandy soils and unstoppable wind.
The benefits are even more apparent this year, with much of the southern Plains locked in a historic drought.
“Soil erosion is terrible when the ground is bare,” says Smith, who grows continuous corn, winter wheat and milo (sorghum), irrigating all of them. “The residue with strip-till protects the ground and weed control is better, too, with the trash.”
Taking The Plunge
Smith farms in southwestern Kansas, about 50 miles from both Oklahoma and Colorado. The area is very arid. Rainfall averages 3-5 inches between May and September, but there’s been even less rain than normal during the past 12 months.
He strip-tilled for 2 years with a neighbor, then bought a 12-row, 30-foot-wide Orthman 1tRIPr with 30-inch row spacing. Smith uses a 275-horsepower John Deere 8530, carrying 1,000 gallons of fertilizer for planting corn at a seed population of 32,000 per acre.
“In the fall, we apply about 210 pounds per acre of anhydrous while we’re strip-tilling, then put down 60-70 pounds of nitrogen as starter with the planter, along with a starter blend,” Smith says. “If we need more nitrogen, we put 32% liquid nitrogen on in the summer through the center-pivot irrigation system.”
Dealing With Residue
There are tradeoffs in switching from ridge-tilling to strip-tilling, Smith says. With ridge-till, it cost money to mow stalks after harvesting corn. He now lightly discs corn stalks 2-3 inches deep to make it easier to strip-till in the fall.
Smith is dealing with two problems: Corn residue that covers the strips and interferes with planting, as well as berms that settle too much during the winter.
“Corn stalks blow back on top of the strips during the winter and spring,” Smith says. “In our area, strong winds are common. This spring, peak winds hit 74 mph. And it’s very common to have winds of 50 mph.”
Also, when he plants corn in the spring, the 2-to-3-inch-high berms have settled and there’s a bit of a dip, which is covered by residue.
“The corn planter can’t handle that much trash,” Smith says. “With the higher ridges in ridge-till, we never had any problems. We re-formed the ridges in the summer and the trash blew into the bottom of the furrows.”
This spring Smith faced the same problem, even with a 12-row John Deere 70-series corn planter equipped with Yetter residue managers. So he removed the ripper shanks from the Orthman 1tRIPr and ran the strip-till rig through the fields.
“We used the trash whippers on the Orthman to re-clean and re-form the strips,” Smith says. “With our RTK guidance system, we used a 15-foot offset in the fields. This kept us from going over the wheel tracks from when we strip-tilled last fall, and it also made it easier for the corn planter to manage the trash.”
Smith thinks that making taller berms when strip-tilling in the fall may solve the problem. He also plans to add hilling discs to the strip-till rig to make taller berms in the fall.
A Better Seedbed
Despite dealing with the problem of blowing corn stalks and settling berms, Smith likes the results he sees from strip-tilling.
“I think we have a bit better seedbed than when we ridge-tilled,” he says. “With strip-till, when we plant corn, we have less of a problem of hitting root crowns from the previous year’s corn crop. And the corn seems to come up fast, too.”
Smith says strip-tillers shouldn’t be afraid of discing corn stalks lightly in the fall before making strips, putting on fertilizer and building berms. He says light discing allows him to smooth out tracks left by the center-pivot irrigation system. But he warns not to disc more than 2 to 3 inches deep.
Since he started strip-tilling 4 years ago, Smith has learned the importance of replacing the points on the 1tRIPr before they are visibly worn.
“The condition of the points affects their lifting action as the 1tRIPr moves through the field,” he says. “If you keep good points on the rig, you get good lift and it makes higher berms. But if you wait until the points are worn down 75% of the way, you lose the benefits of their lifting action.”
Smith says it’s difficult to tell just how much strip-till has contributed to the increase in corn yields vs. ridge-tilled corn yields. He points to the improvements in corn hybrids as a major reason.
“By and large, our corn-on-corn averages 225 to 275 bushels per acre,” Smith says. “We’ve had yields just under 300 bushels per acre.”