NRCS trains farmers to protect the microbes in their soil

The Natural Resources Conservation Service (NRCS) is on a nationwide mission to train farmers to protect the microorganisms in soil—and their relationship to crops— instead of destroying them with fertilizer and chemical sprays, says an Orion Magazine story produced with the Food and Environment Reporting Network.

“Plants pull carbon dioxide from the atmosphere through photosynthesis and create a carbon syrup,” writes Kristin Ohlson. “About 60 percent of this fuels the plant’s growth, with the remaining exuded through the roots to soil microorganisms, which trade mineral nutrients they’ve liberated from rocks, sand, silt, and clay—in other words, fertilizer—for their share of the carbon bounty.”

Just one teaspoon of soil can contain billions of microorganisms like bacteria and fungi. But for the most part modern agriculture has done little to nourish beneficial microbes, and has in many ways destroyed them through heavy tilling, fertilizing and chemical spraying.

“Our entire agriculture industry is based on chemical inputs, but soil is not a chemistry set. It’s a biological system. We’ve treated it like a chemistry set because the chemistry is easier to measure than the soil biology,” said Rick Haney, a USDA soil scientist who developed the now popular Haney Test to check for microbiological activity in soil. For decades, farmers were trained by input companies and agricultural colleges to rely on the NPK test, which looks only at nitrogen (N), phosphorus (P), potassium (K) and otherwise ignores the complex interactions happening below ground.

Today, though, NRCS is trying to convince farmers to disturb the soil ecosystem as little as possible, by adopting no-till techniques and steering away from chemicals and synthetic fertilizers. Dave Brandt, a farmer in Carroll, Ohio, started taking a “microbes-first” approach to his farm in 2004 and has since seen not his only microbial soil health improve, but his bottom line, too. “Brandt has been able to cut fertilizer use on 1,400 acres and eliminate it entirely on 480, with an annual savings of $32,000 and no decrease in yields. In fact, his yields are consistently higher than his county’s average: last year, he raised 10 to 20 bushels more corn per acre, 14 bushels more soybeans, and 30 bushels more wheat,” says Ohlson.

In a Q&A with FERN’s Kristina Johnson, Ohlson explained that it’s only in the last several years that we’ve had the technology to start to understand on a microscopic level what’s happening in the soil. The potential is enormous: “Space is certainly a big unknown, but there are plenty of scientists who say we know more about space than about the soil under our feet.”