Cover crop affects on dryland soil explored
By John O’Connell
Most Southeast Idaho dryland grain farmers have avoided planting vegetation solely to improve soil health, called cover crops, concerned the practice would needlessly deplete their soils of critical moisture.
Cover crop proponents, however, remain convinced the benefits outweigh the costs, even in high-desert rotations without irrigation.
The Caribou Soil Conservation District, which serves a major dryland farming region, has scheduled a forum focused on soil health and cover crops for 10:30 a.m. to 12:30 p.m. Jan. 30 at the senior citizens center in Soda Springs. Call Pauline Bassett at 547-4396, ext. 101, to RSVP.
Chad Bybee, Caribou County’s Farm Service Agency executive director, believes cover crops interrupt continuous cropping systems and break disease cycles, which may prove to be especially important in his region, where growers have suffered yield losses due to barley mealy bug. He also touts the fertilizer benefit of nitrogen-fixing cover crops and the improved moisture penetration and carrying capacity of soils due to elevated organic matter.
“I really project we’re going to see a trend. We’re going to see a lot more acres of (cover crops) in the future,” Bybee said.
In adjacent Bannock County, dryland grain farmer Kevin Koester has an 8-acre cover crop experiment underway. He believes neighbors will pay attention to his results and may follow his lead if cover crops boost his yields.
“It’s one of those things people are kind of interested in, but everybody is a little reluctant to try it. The research hasn’t really been tailored to our part of the world,” Koester said.
The Natural Resources Conservation Service gave Koester cover crop seed — a mixture of legumes, hairy vetch, field radish and clover. He plans to incorporate cover crops into his winter wheat-chemical fallow rotation, planting cover crops in the spring and direct seeding winter wheat into the stubble in the fall.
“There’s some question on how much moisture they’re going to take. Any growing plant is going to take some moisture,” Koester said.
He planted his first winter wheat crop following a cover crop this fall and has seen nothing discouraging thus far.
“I don’t think we’re going to lose as much moisture as we’re going to gain from other benefits,” Koester said, adding his goal is to pick up enough free nitrogen to offset the cost of cover crop seeds.
Koester has been no-till farming for about a decade and opted to give cover crops a try after hearing a presentation by Ray Archuleta, a North Carolina NRCS conservation agronomist.
Though some eastern Idaho growers have tilled cover crops into their soils, Archuleta advocates their use in conjunction with no-till farming to avoid disturbing beneficial soil organisms, waking up harmful bacteria that feed on organic matter or losing more moisture through evaporation.
Archuleta advises grazing cattle on cover crops to remove stubble and naturally fertilize soils with urine and manure. He explained cover crops add diversity to rotations and leak nutrients that support beneficial soil organisms, which are destroyed by tillage.
“For every 1 percent of organic matter you can build, you can store anywhere from 17,000 to 25,000 more gallons (of water) per acre,” Archuleta said.