By David Knopf, News Editor
Doug Peterson, a state soil health conservationist with USDA’s Natural Resources Conservation Service, uses a demonstration on the benefits of no-till planting for soil health that might even sway the most ardent Show Me State skeptic.
Peterson was one of four speakers earlier this month at a Grower Cover Crop Field Event at Missouri Extension’s Graves Chapple Research Center in Corning, a farming community in the far Northwest corner of the state.
An audience of around 30 farmers heard presentations by Peterson; Tim Reinbolt, superintendent of the Bradford Research and Extension Center at the University of Missouri; Rich Hoormann, an Extension agronomy specialist and expert researcher/speaker on cover crops, who discussed their insertion into a corn and soybean rotation; and Charles Ellis, a natural resource engineering specialist for the Extension service, who discussed cover crop seeding methods and timing.
But it was Peterson, the soil health conservationist, who might have delivered the most convincing message and with the fewest words.
Using two dirt samples, one taken from a conventionally tilled field and another from a no-till field, Peterson demonstrated how the no-till soil was better suited for water penetration and less prone to damaging runoff.
He placed a quantity of each variety of dirt in a tall, clear container and then poured equal amounts of liquid into filtering cups that allowed the liquid to drip through to the dirt below. To demonstrate the quantity of water that infiltrated, Peterson placed two other clear containers – also perforated – on a stand with clear plastic trays beneath them to catch water passing through the dirt.
Water dripped into the container of conventionally tilled dirt collected above it, barely penetrating the soil. In a clear contrast, water poured over the no-till variety made its way through the dirt, most of it reaching the catch tray below.
“I remember we used to say that dirt needs to be ground up good before we plant,” Peterson told the audience of experience farmers`, a reference to conventional tilling. “That’s not true.”
According to Peterson, tilling negatively impacts soil health in several ways. Each cut disturbs the soil, he said, which promotes increased weed growth, reduces water infiltration by destroying soil pores, diminishes the soil’s ability to respire (release carbon dioxide into the atmosphere), disrupts microorganism habitats and disturbs beneficial Mycorrhizal fungi and the uptake of nutrients.
The presentations inside the Graves Chapple Research Center – a metal Quonset-style building located at the edge of a field – was preceded by a walking tour of cover crops test-planted in a field about a mile from the center. Farmers attending the conference were led from row to row of covers that included Hairy Vetch, Buckwheat, Crimson Clover, Rye Cereal and others.
Reinbott, superintendent of MU’s Bradford Research and Extension Center, talked a bit about the benefits of each cover, planting schedules and their ability to reseed themselves. Wayne Flanary, a regional Extension agronomist and host for the event, assisted Reinbott through the walking tour.
“There’s no one-size-fits-all,” Reinbott said of cover crop varieties and their adaptability to different soil types and geographic locations. “You’ll have to experiment and find out what works best for you.”
Inside the research center, Peterson placed cover crops in a timeline of research-based growing innovations.
“Cover crops are where no-till planting was 20 years ago,” he said, a reference to agriculture’s gradual adaptation to new techniques. Both no-till techniques and the year-round use of cover crops play important roles in Peterson’s formula for healthy soil.
According to Peterson, the four principals of good soil health are no disturbance, more diversity, keeping soil covered with plants, and having it benefit, in water infiltration, microorganism growth and nutrient retention, from having living roots growing in it year-round.
While it’s not visible to the naked eye — and therefore not as easy to grasp as the tilled vs. no-till water infiltration demonstration – Peterson said that live roots release a variety of living organisms into the rhizosphere, the soil located around the root ends.
Studies have shown that while cover crops assist in the loosening of soil, water infiltration and promoting microbial activity, they also can make economic sense. Reinbott, the Bradford Research superintendent, said that researchers have determined that cover crops such as Austrian Winter Peas or Crimson Clover biologically fix nitrogen. Comparatively, he said, the cost of cover seeds is less than what a farmer would pay for the same amount of applied nitrogen.
Both Hoormann, the Extension agronomist, and Reinbott recommended that farmers new to cover crops should experiment at a pace that makes sense to them.
“You don’t have to plant your whole farm,” Hoormann said. “Take a section and see what works for you.”
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In Monday’s Richmond News: Reinbolt, the Bradford Research and Extension Center superintendent at MU, and Hoormann, the Extension agronomy specialist and researcher/speaker, discuss the benefits of cover crops for soil health and moisture retention, and their insertion into a corn and soybean rotation.