UW Discovery Farms virtual conference helps farmers with soil solutions

Gloria Hafemeister, Correspondent
The farmer-led UW Discovery Farms on-farm research has helped farmers determine the best time and method for applying nutrients according to their individual field needs.

PIGEON FALLS, Wis. – Extreme weather conditions are becoming more of an expected norm in our weather forecasts. University of Wisconsin Discovery Farms' edge-of-field monitoring stations are continuously capturing new data from extreme rainfall to less memorable precipitation events.

During the second of a series of virtual Discovery Farms meetings, co-director of the Discovery Farms Program Amber Radatz shared what has been discovered through these monitoring stations. She was joined by Wisconsin dairy grazier Rick Adamski and  Minnesota crop farmer Brock Olson, both of whom shared what they have learned through some of their on-farm experiments.

Adamski owns Full Circle Community Farm near Seymour, Wis., focusing on certified organic, grass-fed beef. His son has added pastured pigs, laying hens and about 25 acres of fresh vegetables to the mix.

Adamski has been rotational-grazing since 1987. He believes the plants that the cattle graze sink carbon and nitrogen in the soil instead of releasing it into the air.

He also notes, “I believe grazing helps build organic matter and healthy soil produces healthier crops for healthier animals and healthy people.”

Adamski likes to maintain diversity in his pasture mix and the vegetation is used as a cover crop, meaning it covers the soil year-round, trapping more of the greenhouse gases. It also prevents soil erosion by slowing runoff from rain and snow and reducing the impact of raindrops on the soil surface. 

He also points out that the organic matter makes the soil more like a sponge, preserving moisture in dry years and preventing runoff and improving drainage in wet years.

“The benefits of organic matter are not noticed immediately,” Adamski said. “But we do see advantages including less investment in nutrients.”

He added, “On our farm we depend upon our legumes and animal manure as our nutrients. This cuts down on the cost of production.”

Olson received a grant from the Minnesota Corn Growers Association to experiment with cover crops in his corn-soybean rotation. The first year he no-tilled winter rye into the soybeans to help with erosion problems that tend to occur after harvest.

He then let the rye go to seed and harvested it for seed at the end of July.

Olson has found there is a real market for this seed among local growers interested in experimenting with cover crops. 

Cover crops have played a big role in holding moisture and nutrients and preventing runoff on farms. Diversity of plants helps build soil structure.

After harvesting the rye, he established a cocktail mix of sorghum, sudan, oats, winter peas and tillage radishes. In spring, he no-tilled corn into the cover.

Olson said, “I had been concerned about too much residue, but by spring it had thinned out because some of the biomass killed off with freezing and other species remained alive through the winter.”

After harvesting the corn that year, he established winter rye, no-tilling soybeans into the residue in spring and then killing off the rye.

He reports, “Right after I planted the soybeans, we had an eight-inch rain on that steep hill. Across the fence line, a recently planted corn field that had bare ground had gullies washed through it that took a lot of corn seed out of the rows. My field next to it had no erosion.”

Among the 130 participants in the virtual Discovery Farms conference were several who had questions about how to utilize manure on cover crops.

Radatz said there are many farmers who plant rye as a cover crop immediately after corn silage, or they have the cover interseeded with the corn, which grows as soon as the corn is harvested and the light hits the plants. Those farmers spread their liquid manure on the cover crop or incorporate it into the field and they have found that it serves as a nutrient source and also provides the necessary water to get the rye growing.

She also mentioned, “In northeastern Wisconsin, the Natural Resources Conservation Service has been doing a lot of work with this and they have found an advantage to interseeding the cover when planting corn, because the cover is better established and able to handle the manure after the corn silage harvest.”

Radatz also outlined some of the projects Discovery Farms is currently working on. She said there are several keys to reducing the risk of soil and nutrient loss in surface runoff and it is important to understand how weather interacts with a particular management system.

Interseeding the cover when planting corn helps the cover to be better established and able to handle the manure after the corn silage harvest.

“First, we need to understand that runoff will happen, but as a farmer you can control what is in that water runoff,” she noted.

She also pointed out that a farmer can control soil loss and nutrient loss by understanding timing as well as ground cover. Rain on frozen ground, for instance, will have different results in terms of runoff than rain on thawed ground. 

Runoff is driven by snow melt and smaller events, but climate changes will influence soil and nutrient loss. One winter there may be rain on snow that creates a crust of ice on the surface, but another winter there may be the same amount of precipitation, but less runoff because of consistent temperatures and snow cover. Water does not soak in but instead runs off.

Extremes any time of year will present challenges. Radatz said that Discovery Farms has determined that the most extreme storms happen in July and August.

Knowing that it is the extreme storms that have the potential to do damage, she suggested developing a system that provides adequate cover to protect the ground during the months when there would not be a crop growing.

“Ideally, you should have a cover that provides enough bio-mass or at least one species that survives through the winter,” she said.