IOWA CITY — No-till cultivation combined with cover crops can benefit both the environment and farmers’ bottom lines, several soil health experts said Thursday at a workshop sponsored by the Johnson County Soil and Water Conservation District.
In 1971, when Dave Brandt of Carroll, Ohio, adopted no-till cultivation, tests indicated that his soil contained just 0.5 percent organic matter, a key component of healthy, productive soil.
This year, after 43 years of no-till farming and 36 years of planting cover crops, his soil contains 7.5 percent organic matter, Brandt said.
Never-plowed native prairie would contain about 6 percent organic matter, other speakers said.
“It took me over 40 years of trial and error to get it there, but we can do it faster. You can add as much as 1 percent organic matter per year by growing 25,000 pounds of cover crop biomass per acre,” Brandt told about 90 farmers and conservationists gathered at the Iowa State University Extension building.
Brandt said the cover crops alone, with no supplemental fertilizer, provide enough nutrients to grow 190 bushels of corn per acre on his farm. His cost of production, he said, is much lower than that of farmers practicing conventional tillage because he spends much less on fertilizer, herbicide and pesticide and makes many fewer trips across his fields with machinery.
The organic matter combined with abundant pore space for air and water increases his soil’s absorbency, resulting in minimal soil erosion and runoff of pollutants, he said. Because he does not disturb the soil with cultivation, beneficial microbial organisms flourish.
During the 2012 drought, Brandt said his no-till/cover crop fields yielded 174 bushels of corn per acre while a neighbor’s conventionally tilled fields yielded 30 bushels per acre.
“In 40 years I have never qualified for a crop insurance claim,” he said.
The cornerstones of soil health are little or no disturbance, diverse crop rotations and year-round living roots in the ground and residue on the surface, according to soil scientist Rick Bednarek with the U.S. Department of Agriculture’s Natural Resources Conservation Service.
All those hallmarks can be achieved, he said, through no-till cultivation and cover crops.
Steve Berger, another no-till/cover crop pioneer, said those practices have greatly increased the organic matter in the 2,400 acres his family farms in Washington County.
Berger said it is a myth that no-till farmers have to wait longer for soil to warm and dry before they can plant in the spring. “We are not being delayed at all,” he said.
Berger said even minimum occasional tillage can disrupt beneficial microbials for years.
“Don’t till the soil. Get something growing on it (for as much of the year as possible). And pay attention to what’s leaving your land,” Berger advised.
Jay Fuhrer, an NRCS soil scientist from Bismark, N.D., said it took half his 34-year career to understand the importance of healthy soil.
“We were trying to minimize the loss of a degrading resource. Now we are building soil health,” he said.
Fuhrer said cover crops add nutrients to the soil and help keep them in place.
“I think the answer to nitrate pollution in streams and lakes is healthy soil with cover crops,” he said.
Rancher Jerry Doan of McKenzie, N.D., said cover crops have helped him build soil health while providing low-cost winter feed for his cattle and cover for wildlife.
“My quality of life goes up, and my expenses go down. It’s good for nutrient cycling, soil health, cattle health, water quality and livestock,” he said.
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