December 3, 2018
Keep soil in place. Speed water infiltration. Improve soil structure. Give nutrients from the soil back to crops. Get better weed control naturally.
Those benefits and more from a no-till and cover crops system that builds healthy soils were reinforced over and over to Barb Stewart for two decades, up until she retired last year, as a Natural Resources Conservation Service agronomist for Iowa.
While she learned from what she saw on other farms and from NRCS and researchers, she also put the technology into practice on her own farm fields.
Stewart began working for NRCS in Clarke County in 1977. She served as district conservationist for three years in Adel and five years in Newton before beginning work in the agency’s state office in 1988.
“When I was cleaning files out as I retired, I came across a photo of me in a cover crop field in the 1980s,” she says. “That’s just one signal that cover crops aren’t new, but we’ve learned they have many more advantages than we once realized.”
Early thoughts on cover crops and no-till focused on their ability to control soil erosion, Stewart recalls. But their use escalated as their ability to increase water infiltration and hold nitrogen in the soil for plant use instead of allowing it to enter underground water became better known.
“A healthy soil can do a lot to filter nitrate out of water; we could see that even in a 3-inch-deep slab of healthy soil in our rainfall simulator demonstrations,” she says.
On-farm testing
Soil health practices caught on in Ohio and Indiana before Iowa, Stewart says. But as NRCS began to promote them in Iowa, she and husband Randy were eager to test them on their own fields. “We were among the first to use cover crops in Wayne County in what I call the second round of cover crops,” Stewart says.