Strip tillage gaining ground, yields

WEST LAFAYETTE, Ind. – When it comes to preparing a field for planting, farmers usually fall into one of two camps: Those who till it all, and those who leave it all untilled.

There is a middle ground, so to speak, between conventional tillage and no-till systems.

Strip tillage is catching on across Indiana and other Corn Belt states, said Tony Vyn, Purdue University Cooperative Extension Service cropping systems specialist.

“In Indiana alone, we had at least 150,000 acres of strip-till corn grown in 2003,” Vyn said.

“My guess is that strip-till acres are growing at the rate of 25 percent per year.”

Warm soil faster. Strip-till combines the soil drying and warming benefits of conventional tillage with the soil-protecting advantages of no-till, Vyn said.

In addition, corn grown in a strip-till system consistently yields as well as corn grown in a conventional-till system, and can yield better than no-till corn crops planted on the same date, he said.

Soybeans also can be grown in a strip-till system, although no-till remains the preferred planting method.

What research says. Vyn and other Purdue researchers have examined strip-till for the past decade. They’ve concluded that strip-till provides a host of planting pluses.

“The key advantages of strip-till compared to no-till are that strip tillage enables the soil to warm up faster and dry out sooner in the intended row zone,” Vyn said.

This means much more planting flexibility in the spring. A strip-till corn farmer will be able to plant their corn sooner in the spring.

Under cover. Strip tillage also has the big advantage of retaining residue cover, Vyn said.

“With strip tillage we maintain two-thirds – and sometimes three-quarters – as much residue as we do with an undisturbed no-till soil,” Vyn said.

From a conservation tillage point of view, he says strip tillage is almost as effective as a “pure, undisturbed no-till.”

What is it? Like its name implies, strip-till involves plowing raised, narrow strips from one end of a field to the other.

The raised strips, or berms, should be 3-4 inches high and 10-12 inches wide.

Strip-till is normally done for crops planted in 30-inch rows. The soil on either side of the berms remains untouched.

Fall preparation. Farmers perform strip-till operations in the fall, following harvest.

By the time spring rolls around, the berms have settled to a height of about 1-2 inches. Seed is planted directly into the strip rows.

Field conditions also dictate when strip-till operations begin, Vyn said.

Soils can be too wet for strip tillage even though they may still be suitable for a full-width tillage system.

GPS helps. Technology advances have made it easier for farmers to plant into strip-till rows, Vyn said.

Automatic tractor steering controlled by Global Positioning System (GPS) units allow farmers to plant within 1 inch of the berm center, even at night, he said.

GPS devices also make it possible for farmers to strip-till fields with tillage equipment that’s only half the width of their row crop planters.

Another key feature of strip tillage is that it allows for fertilizer placement in the strip zone, Vyn said.

“Applying that fertilizer concentration to the area where extensive roots develop the following year can result in yield advantages for strip tillage.”

Yield data. Vyn said strip-till corn yields have tended to be better than those for no-till, when corn is planted into high-residue situations, such as corn after corn or corn after winter wheat.

But following soybean stubble, the yield advantage with strip tillage compared to no-till is not a certainty, and may be most likely in wet spring situations when no-till corn planting is delayed well past the optimum date.