Soil Health Profile

Originally posted on USDA website

Written by conference speaker David Brandt

Ohio soil health pioneer forges new frontier in farming

While David and Kendra Brandt like what they see from the soil health system they’re using on their central Ohio farm, everything they do still has to pass muster through the combine’s yield monitor.

They’ve used no-till on their corn, wheat, and soybean operation since 1971, but when David saw a drop in corn yields in 1978, he added hairy vetch and winter peas to the system to get more nitrogen.

“We were using commercial nitrogen then, and I wasn’t really thinking about the health of the soil,” Brandt says. “We saw some improvement in water infiltration at the time, but we didn’t reduce nitrogen inputs until we learned our soils were changing and we didn’t really need it,” he says.

Reducing Crop Inputs

“Cutting back on commercial inputs has been a tough one for me, because we’ve always been taught we need so many pounds of nitrogen, phosphorus and potash to grow a decent corn crop,” Brandt says. “We’re learning now with cover crops that we don’t need to buy those additional nutrients because we can bring them up from deeper in the soil. They just weren’t available to the crop before.”

“In fact, we’ve learned in the last two years that we can go to using almost no purchased commercial fertilizer or herbicide and still produce a great crop of corn and beans.”

“Our nitrogen use in fields without cover crops is 170 pounds an acre. Where we have cover crops and longtime no-till, we’re down to about 20 pounds an acre. That’s more than $100 an acre per year nitrogen savings, and we’re not sacrificing any yield.”

The nitrogen comes from cover plants like hairy vetch, Austrian winter peas, cow peas, and sun hemp. They pick out nitrogen from the atmosphere and translocate it into nodules on the roots, Brandt says.

“Some of those nodules will be as big as your thumb. Soil bacteria break them down, and the nitrogen is released slowly in an organic form that the corn plants can use,” he says.

Every cover crop grown on the farm has at least two species. Brandt is moving toward multiple species in the blend, because some—like hairy vetch, late-planted winter peas, cereal rye, barley and wheat––will stay green and keep growing through the winter.

“If we can keep something green in the ground with multiple species, we can build soil faster. So we like multiple blends better than two species,” he says.

“It will take 6-7 years to change or improve a soil with just no-till, but that time can be shortened to 4-5 years or as few as three years if you also use the right blend of cover crops.”

Covers bring up nutrients

Brandt is trying 8- and even 14-way blends of covers. “I’d like to learn more about which covers can bring up trace elements,” Brandt says. “We’ve seen buckwheat bring up phosphorus and zinc, for instance, and sunflowers bring zinc up too.”

Yet, he won’t put in a cover if it won’t pay for itself. “You shouldn’t spend any more for seed on a cover crop than what you can gain in reduced fertilizer costs or increased yields. That’s always been our philosophy,” he says.

Generally for Brandt, cover crops cost from $20 an acre to $35 an acre.

Suppressing pests naturally

The soil health payoff can come in other reduced inputs, too. “We’ve had less weed and pest pressure as we’ve gone along. We see more host insects that will prey on the insects we don’t like to see in the fields,” Brandt says. “We’ve found radishes give off a sulfur smell, for instance, that fumigates the soil and reduces cyst nematodes and slugs in the soil. We’re proud to say we’ve quit using insecticides on the farm.”

Their cover crops suppress winter annuals and broadleaf weeds, and Brandt has cut herbicide use in half.

“We have less sudden death syndrome and less white mold in our beans and less northern corn leaf blight in our corn, too,” he says.

More Microbes a Key

Brandt says he didn’t realize microbes were so important to farming a few years ago. “But I’ve read about how vital they are, and now I see as they increase, we see more good things happening in our soil—more nutrients being released, more water infiltrating into the soil. The more microbial activity we have, the better off we are,” he says.

“I’m really intrigued with the amount of water infiltration we’re seeing with our cover crops. As we go to cover crops with deeper roots, and bigger root masses, we’re seeing rainfall dissipate through the soil better. We don’t have water pockets in our tight clay soils any more.”

Cover crops also moderate soil temperatures. “On hot summer days, with air temperatures over a hundred degrees, our neighbors had soil temperatures of 118 degrees and ours was 86 degrees. Our corn really looked great at those times,” Brandt says.

Sharing the knowledge

Brandt has had to learn about soil health by trial and error on his farm. But he wants others to have an easier road. “I’m trying to pass on what we’ve learned here. I don’t want everyone to reinvent the wheel. I want people to see our failures and our successes,” he says.

“So many farmers have learned to sit on the tractor seat and let an agronomist make their decisions. I like to have farmers come and feel the soil here, dig in it, smell it, and see for themselves how healthy soil should look and feel. That’s when they get excited.”

That includes his banker. “It was hard to get him to understand what we are doing here until we got him out here. Now the quality of our soils and our reduced inputs show up on our balance sheets,” Brandt adds.

“And our landlords are tickled. We can show them how we’ve added organic matter to their soils and made their land more productive, and at the same time kept increasing their crop yields.”