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Be willing to Trim Tilling
Using cover crops can reduce disking operations and improve soil

By Jeff Gelski
Managing Editor, The Grower Magazine

A new farming practice, designed to cut costs and improve soil quality through the use of cover crops, is still developing. In fact, it’s so new that no definite term really exists to define it..

No-till farming works in the case of Cedar Meadow Farms in Holtwood, Pa. There, Steve Groff grows vegetables such as tomatoes, pumpkins, peppers, broccoli and sweet corn without tilling at all.

Reduced tillage works as the definition for research at Michigan State University. Work there focuses on cutting down the number of tillage operations for potatoes and processing tomatoes.

At the University of California, the technical definition of conservation tillage means farming with 30 percent or more of the ground covered in residue, which reduces primary tillage, says Jeff Mitchell, vegetable crops specialist with the University of California, Davis. Researchers there have focused on several vegetable crops and several types of farming operations, including reducing tillage operations and strip-till farming.

Reducing tillage operations save money on labor and diesel fuel, store more carbon in the soil and reduce air pollution because it cuts down on tillage passes, Mitchell says. Researchers have challenges ahead of them, too, in the areas of killing the cover crop, dealing with cooler soil temperatures during the spring planting time and making sure yields are about the same as conventional tillage farming.

“We have 150 years’ experience with tillage and pretty much know what to do in any given situation,” Groff says. “This is a whole different situation. I learn something every year.”

Hill country

Cedar Meadow Farms sits on hill country in southeastern Pennsylvania, an area where no-till farming works well to offset land prone to erosion. In contrast, no-till farming may not be the best option for heavy soil that sits on flat land and does not drain well, Groff says.

Groff says he has used no-till methods for corn and soybeans for 20 years and started no-till methods for vegetables seven years ago. He farms 25 acres of pumpkins, 20 acres of sweet corn, 20 acres of processed tomatoes and 5 or 6 acres of fresh-market tomatoes, peppers and broccoli.

No-till pumpkin farming has caught on nationally, Groff says. The practice makes it easier to clean off the pumpkin and gives consumers a cleaner field to peruse in you-pick operations.

Total savings of no-till transplanting tomatoes amounts to $675 per acre annually, according to the farm’s Web site at http://www.cedarmeadowfarm.com. Nearly $500 of it comes from material, labor and time savings when eliminating the use of plastic mulch. Tillage savings comes to about $40 per acre and pesticide savings comes to about $125 per acre.

Groff plants cover crops in fall. For transplanted vegetables, he likes to use a three-way mix of hairy vetch, crimson clover and rye.

Earthworms and other biological life have increased under no-till operations. Cedar Meadow Farms has seen its soil organic matter go from 2.7 percent to 4.3 percent, Groff says.

Cold, wet soils with lower temperatures in the spring can cause problems and disrupt planting schedules under no-till farming, Groff says. Special equipment also might be needed for the practice. Cedar Meadow Farms has worked with an Ontario company, R.J. Equipment, to make a no-till vegetable transplanter and a rolling stalk chopper.

The rolling stalk chopper has blades that kill the cover crop, but herbicides still are needed to finish the job, Groff says.

Some vegetable crops may not work in no-till farming. Root crops, such as carrots and potatoes, need the soil disturbed during harvest, Groff says.

“My whole point is for people to think about reducing the amount of tillage they are doing, or using cover crops instead of steel to create a better soil,” he says.

Potato rotation

Researchers at Michigan State University know potato farmers probably always will need to do some tillage, but they would like to cut the number of tillage operations in half, says Sieg Snapp, an assistant professor in integrated vegetable management.

A six-year project, now in its second year, has focused on potatoes and processing tomatoes.

“With potatoes, we’ve got something in hand we could try on a big scale in a couple years, but with tomatoes we’ve got a long way to go,” Snapp says.

A project covering two 3-acre sites on two research farms examines the possibility of potato farmers going 20 months without tilling. They would seed red clover into wheat as a cover crop. After the wheat is harvested, the red clover still is coming on strong, Snapp says.

The process, it is hoped, will lead to better soil coverage, improved irrigation efficiency and better water filtration.

Snapp says some sandy soils in the state have a low number of organic carbons. Soil organic matter can be as low as 1 percent.

“An increase of 20 percent would make a big difference in the water infiltration rate,” she says.

California conservation

Research on conservation tillage in California started with one site in 1996, Mitchell says. Now, it takes in more than 35 sites. About 80 people, including university personnel, farmers and public agency officials, are involved.

One project has focused on reducing tillage by following processing tomatoes with cotton, which has cut out five or six tractor passes, Mitchell says. After planting cotton, only two operations are needed: shredding and cleaning out furrow of cotton and transplanting tomatoes the next year. Under a standard tillage operation, the farmer would need to make several more operations, such as chopping cotton stalks, undercutting cotton stalks, disking the field twice, listing the beds and mulching the beds.

Yields have run about 10 percent lower in the conservation cotton tillage system, Mitchell says.

The process also needs cultivating equipment that can get through high, thick residue, he says.

Contact Jeff Gelski at (800) 255-5113, ext. 677, or jgelski@vancepublishing.com