Cover crops: Improving soil health and water filtration

Gloria Hafemeister
Derek Van de Hey, New Horizons Dairy, Brown County, shared his ideas about manure management, cover crops and no-till with other producers at a healthy soils field day near Hubertus.

HUBERTUS – It was an unlikely place to hold a cover-crop field day but farmers from around Dodge, Washington and Waukesha counties gathered at the Heiliger Huegel Ski Club near Hubertus on Oct. 9, to look at the fields established with pollinator plants and see the emerging cover crop in a soon-to-be-harvested corn field.

The cover crop was established with help from the Oconomowoc Watershed Protection Program, co-hosts of the event.  Co-sponsors were Tall Pines Conservancy with help from the Wisconsin Department of Agriculture, Trade and Consumer Protection and Professional Dairy Producers of Wisconsin.

The cover crop on the land owned by the ski club was aerial seeded by Back Nine Aerial Applications, owned by Dwayne Deakins. Pilot Anders Vetch was on hand to describe the project that successfully covered more than a thousand acres last year and more than 2,000 acres this year. The aerial seeding was done through the Oconomowoc Watershed Protection Program.

Three of those fields, a total of 52 acres, were outside the Watershed area.They are managed by the Oconomowoc High School FFA group.

According to Darrell Smith, the Watershed ag project coordinator, many of the fields in the watershed area are very small and using a fixed-wing aircraft to establish the seeding would not be practical.

He further explained, “Aerial application can be done when it's impossible to use ground equipment, such as when crops are still standing or the soil is too wet.”

Smith said farmers want to preserve topsoil and the nutrients lost if that topsoil is lost each year. Seeding cover crops also improves water filtration, allowing farmers to possibly get on fields sooner. Crops are healthier as well.

Cover crop experience

If a farmer can get nitrogen credits, it could reduce the amount of fertilizer used in future years, "but farmers are going to want to get experience with that first before they back off," said Smith. "You have to hit it at the right time. You have to have the right weather that germinates the seed, and everything that goes along with that."

Two farmers who have been successfully working with cover crops for many years were on hand to describe their successes and provide advice for getting started.

Derek Van De Hay of new Horizons Dairy in Brown County described how cover crops have helped loosen the heavy clay soil on their farm.

The family farm that includes three brothers and their dad crops 2,500 acres to support their 850 cow dairy herd and 1,750 young stock. 

Van De Hay says, “We started using cover crops in 2007 for extra heifer feed; that evolved into using cover crops for effective cover and soil health once we realized the multiple benefits.”

In the same year they started no-tilling many of their fields to build an effective soil health system and improve infiltration.

As they learned and observed the benefits they increased their acreage and in 2017 they planted all 1,760 acres in cover crops and no-tilled those acres this year.

They use a variety of cover-crop seed mixes according to the benefit they are seeking on a particular field.

Cover crops benefits

This year’s weather challenges made the benefits more obvious, he reports.

“We had a very dry summer and an unusually wet fall,” he notes. “The cover crop fields are significantly more stable than the conventional fields. When we harvested our corn the ground supported our equipment while the neighbors across the fence line made deep ruts using four-wheel drive tractors.”

The goal is to get the cover crops established as soon as wheat and silage corn is taken off. That gives the plants a longer time to grow before winter hits.

He applies manure onto the covers in the fall and after the corn is planted. Using an irrigation method, he monitors how thick the manure is getting in order to adjust the volume. The manure from the top of the lagoon has more water and will not burn plants but as it gets thicker they need to cut back on the volume.

Due to increased soil health he is now able to distribute manure in the spring, alleviating pressure on fall applications and allowing more time to plant covers after harvest.

Cover crops also help the Van De Heys improve nutrient uptake and drastically reduce their need for commercial fertilizer and weed control.

Tony Peirick, a Watertown farmer who is co-chair of the Dodge County Healthy Soils Healthy Waters group, said he has seen the weed-control benefits of the cover crops and in the years since he has been practicing no-till and utilizing cover crops he has seen his fertilizer and herbicide costs go down.

Both Peirick and Van de Hey provided balance sheet information to back their observations. In both cases fuel and equipment costs were lower because of fewer passes over the field.

Peirick points out that those savings may not necessarily be seen immediately. He said it may take about five years to see significant changes in yields and input costs.

He also notes, “My crops may not look as good as the neighbors’ early in the summer but later in summer when the cover crops begin to break down they catch up quickly.”

This year in particular all the heavy rain washed away many of the nutrients in the soil and by August much of the corn was starved for nutrients. The cover crops that were breaking down slowly over the summer then took over, feeding the plants just when they needed it most.

Also on hand to share their cover crop experiences were farmers taking part in the new Cedar Creek healthy soil group in Washington County.

Al Schmidt who farms in the town of Jackson said he has about of mile of creek going through his land and keeping the soil from entering the creek is a priority. 

He said, “We have found that producers talking with each other is more effective than anything. We share ideas and keep learning new ways to improve soil health.”