Successes, failures highlighted at cover crops field day

Ray Mueller
A field with a modest cover crop growth following the harvest of corn for silage on the John Leick farm at the edge of Greenleaf in Brown County.

BLACK CREEK - Successes and failures with multiple species of cover crops, viewings of equipment being used in cover crop establishment, and late-season applications of liquid manure into stands of those crops were highlighted at a field day sponsored by the Lower Fox River Farm Demonstration Network.

The multi-stop tour of fields in Outagamie and Brown counties drew a crowd of about 50 area farmers, representatives of farm implement dealerships and companies, crop consultants, and county and federal agency employees overseeing natural resource conservation programs.

Six farms in the two counties are participating in the demonstration network in a cooperative venture with the Natural Resource Conservation Service (NRCS), the land and water conservation departments in the two counties, and the Great Lakes Commission, which is providing the major funding for the project. Brent Petersen of the Brown County land and water conservation department is the network coordinator.

Brent Petersen

Winter wheat lead-in

With winter wheat fields being the prime candidates for cover crops in the area because they are usually harvested by early August, the Greg Nettekoven farm at rural Black Creek in Outagamie County served as the day's first stop. The Nettekoven farm is a member of the demonstration network.

At a field next to the Nettekoven farmstead, attendees learned the importance of not rushing the planting of corn if soil conditions are not ready and of checking an entire large field rather than only a portion of it. A crop consultant admitted being guilty of the latter mistake, which resulted in a loss of corn stand population density in a portion of the field.

Nettekoven indicated that the no-till field, from which wheat yielding 95 bushels per acre was harvested in 2015, also featured a red clover crop which was frost seeded into the wheat during the spring last year. Once the wheat was harvested, the red clover exploded into a growth approaching a height of two feet, was killed with a Round-Up herbicide application before the winter and left a nitrogen credit for this year's corn crop.

About 10 acres of the field of corn that was planted this spring lost a portion of the intended population of 32,000 plants per acre because proper closure of the seed rows was not achieved in the areas with fairly wet soil. The lesson of having to “be patient” when planting was learned in the wake of current estimates of 26,000 corn plants per acre on about 10 acres of the field for the upcoming harvest for grain.

A minimal amount of liquid manure was evident on the soil surface a few hours after an application with a Bazooka Farmstar low disturbance unit on the Conrad Liebergen farm south of Wrightstown.

Imported vertical tiller

To clear the fields of plant debris from cover crops, Nettekoven is happy with his Lemken Vertical Tiller that is made in Germany. He pulls it with a Case IH 305 Magnum tractor at a speed of 8 to 10 miles per hour with a capability of covering 10 to 12 acres per hour.

Nettekoven explained that the unit works well to break up remaining corn stalks and even standing alfalfa. With its weight balanced toward the back, the tiller churns all of the soil to a chosen depth of two to three inches, he pointed out. Another use of the Lemken tiller is to provide a slight soil cover on seeds that have been spread on wheat stubble by an aerial seeder.

Provided by the Larsen Cooperative, a Case IH 4520 tractor equipped with an aerial flow seedbox and a 70-foot arm reach was on display in another field that Nettekoven crops. The unit can apply fertilizer and seeds on the same trip.

Need for nitrogen

For the cover crop which was seeded in mid-August after the harvest of winter wheat yielding 115 bushels per acre, Nettekoven chose a per-acre seeding mix of 25 pounds of spring barley, 25 pounds of leftover soybean seed, and 2 pounds of tillage radish.

Very different rates of growth were evident for those species in that field with the soybeans having only a minimal presence. Nettekoven mentioned an early period of yellowed foliage in some areas.

Petersen suggested this might have been due to a shortage of nitrogen after the heavy wheat yield along with possible soil compaction in the headland area. He emphasized that an adequate supply of nitrogen is essential for supporting a good cover crop growth of tillage radish.

Even with the absence of significant cover crop in portions of fields by the third week of October, Petersen stressed that this is better than the alternative of having virtually bare soil and minimum biological activity after the mid-summer harvest of wheat. His preference is to “harvest the sunlight” that is available for the final three months of the growing season.

Herbicide carryover

At Van Wychen Farms, between Freedom and Wrightstown, the use of certain herbicides to control weeds in corn hurt the effort to establish the clovers and annual ryegrass interseeded by about the time the corn was reaching knee height, Petersen reported. He identified the culprit herbicides as Lumax, Dual, and Callisto and suggested that Sharpen and Resolve are better choices because they would have a shorter residual carryover period.

The per acre seedings of 15 pounds of crimson and red clovers and 2 pounds of tillage radish hadn't shown much growth by mid-August but some areas of a water-logged corn field had nearly full ground cover by the time of the Oct. 18 field day. Because of their need for sunlight, Petersen observed that the cover crops need to be seeded into corn well before a canopy is created.

At a 2nd field of corn waiting to be harvested for grain on the Van Wychen farm, the field day attendees were shown an example of better soil structure in the wake of four years of a no-till practice. One of the signs of that was how a population of earthworms had pulled previous plant debris into their holes. Again, due to the use of a herbicide not long before the seeding of radish and clover, the establishment of the cover crops was spotty late in the season.

Innovative equipment

Van Wychen Farms, which is operated by George, Nick and Matt Van Wychen, is a charter member of the demonstration farm network and a pioneer in the area for growing cover crops. Petersen noted that Nick is adept at building units for applying the cover crop seeds into standing crops.

One such device is the seed box for aerial application that is adaptable for placement on several major pieces of field equipment. A special feature is the inclusion of three meter sizes for handling the differing sizes of the cover crop seeds.

For the field day, the aerial seed box was attached to a Valmar 3255 pneumatic granular application. Nick Van Wychen said the unit was used to seed about 300 acres this year.

Petersen announced that the Nature Conservancy, which supports the goals of the demonstration project, has donated an air box seeder that farmers are invited to use without cost for planting cover crops. They should contact Petersen by email to or by phone to 920-391-4643.

Manure applications

Two examples of low soil disturbance for liquid manure applications into existing cover crops were additional stops during the field day tour. The first was on the Conrad Liebergen farm south of Wrightstown, where a Bazooka Farmstar coulter type unit was used earlier in the day, leaving a bit of liquid manure on the soil surface.

That 30-foot wide unit features a combination of opening and closing disks. Using grant money, the Outagamie County land and water conservation department purchased the Bazooka unit and is making it available to farmers at no cost.

In addition to using it for liquid manure application into cover crops without destroying the foliage, the Bazooka also could be used to apply liquid manure in a thinning alfalfa stand scheduled to be taken out after the first cutting the following spring to be followed by a late planting of corn, Petersen suggested. In either case, he noted that the minimal disturbance of the soil in the autumn allows the existing foliage to continue growing and take up the nutrients in the liquid manure.

Special equipment

For the final stop of the day, attendees visited a field at the edge of the village of Greenleaf to see a low disturbance ETS (Environmental Tillage Systems) Honey Warrior deep coulter liquid manure applicator and a Sunflower company vertical tillage unit equipped with a air seeder box. The land is owned by John Leick and cropped by the nearby Wiese Bros. Farms.

The 40-foot wide Honey Warrior unit, built by a Minnesota-based company, has the capability of making slits 10 to 12 inches deep for the placement of liquid manure at volumes of up to 20,000 gallons per acre. Required tractor horsepower is to 20 to 40 per row, depending on the tillage depth.

A recent application of 18,000 gallons per acre into a cover crop on the field did not leave any evidence of liquid on the soil surface. The manure application part of the unit is provided by Puck Custom Enterprises of Manning, IA.

A Bazooka Farmstar vertical tillage unit is suited for the minimal disturbance of soil as it applies liquid manure into cover crops or standing alfalfa late in the growing season.
A liquid manure application unit made by Puck Custom Enterprises of Manning, IA, sits atop a low soil disturbance Honey Warrior tillage unit made by the Minnesota-based Environmental Tillage Systems.

Cover crop menu

For the cover crop, 35 pounds of a mix of oats, annual rye, and tillage radish were sown per acre with a Valmar air seeder attached to a Sunflower vertical tillage unit, which features a rolling basket at the rear to improve seed to soil contact for germination. With this combination of equipment, only a single pass is needed to till the top 2 to 3 inches of soil after a harvest of corn silage and to spread the cover crop seeds.

ETS also makes a Soil Warrior X unit that is designed for deep zone tillage of as many as 16 rows with widths as narrow as 20 inches. It is capable of being equipped for applying liquid or granular fertilizer.

Commenting on the practices at the site, NRCS conservationist Barry Bubolz cited the importance of planting a cover crop immediately after a corn silage harvest as a part of a whole system approach to improving soil health, supporting biological activity in the soil and protecting natural resources. Another recent activity at Leick's field was the installation of a series of Hickenbottom water intake risers to accommodate drainage of runoff water from within the site and adjacent land.

A Lemken tiller made in Germany serves Greg Nettekoven for tilling fields after cover crops were grown on them.