The use of cover crops has received increasing interest among Wisconsin growers for a variety of reasons. Suggested benefits of cover crops include improved soil quality, reduced soil erosion, nutrient sequestration, pest and weed management, and restoration/maintenance of soil biota on “prevented planting” acres. Thousands of acres in the state were not planted in 2013 because of wet soil conditions, especially in the North Central portion of the state. Concerns associated with cover crop use in the state include the ability to establish the crop because of cold weather (measurable snow was recorded in the state on 20 October) and the ability to terminate the stand the following spring.
An informal poll of selected county agents was made early this fall to assess the adoption of cover crops in throughout the state. A summary of their responses are offered below, which have been sorted by region of the state.
East Central: Adoption currently less than 10% of available acres, but an increase over what was observed a few years ago. Some are planted to address forage shortages brought on by recent droughts. Generally planted after shorter-season crops such as processing vegetable crops (sweet corn, snap beans, peas) and corn silage. Winter wheat is often planted after soybean and functions as a de-facto cover crop. Most are drilled, but there is an aerial applicator in the region that is aggressively promoting aerial seeding. One of the CSCAP cooperating farmers reported that they had aerial seeded 140 acres of a rye and radish mix into standing corn. They also planted 270 acres of prevented planted land to a mix of radish, turnip, soybean, and annual rye. An aerial applicator in the area plans to seed 20,000 – 30,000 acres this year, and has the capacity to aerial seed 100,000 acres over several counties. A second CSCAP farmer in the region hosted a cover crop field day on his farm that highlighted the use of 17 different cover crop plantings.
South Central: Estimates of about 10% of the growers are using cover crops when possible for a variety of the reasons stated above. An on-farm study showed higher soybean yield following corn and processing crops where a cover crop was planted. Seed availability is becoming an issue in some areas. There is some concern about unexpected insect pests following a cover crop as flea beetles were an issue after “tillage radish”.
West Central: Rye is grown on erodible ground that had been corn silage. Some use of the cover crop as forage because of drought conditions. This area has a large amount of coarse-textured soils and growers are hoping cover crops will capture some of the excess N. This region of the state experienced continuous spring rains and many growers planted cover crops on prevented planting acres to protect the soil, reduce weeds, and manage compaction. Another county in the “Driftless Area” of the state reported 1,045 acres planted in 2012 as part of a cost-sharing program. Much of this was following corn silage. There appears to be substantially more acres of cover crops in this county, but are not reported by the farmer. Farmers have some difficulty planning planting cover crops following corn silage, as it is difficult to know which and how many acres will actually be chopped to fill their storage structures. Cover crops are drilled here.
Northern: There is interest in the use of cover crops in Northern Wisconsin, but there are fewer acres of annual grain crops and farmers are confronted with a much shorter growing season than their colleagues a couple hundred miles to the south. A few growers are experimenting with cover crops for some unique reasons. One is the seeding of a cover crop after killing/tilling a poor forage stand and then using the early growth of the cover crop as forage. The field is then reseeded to perennial forage with the hope that the cover crop controls allelopathy and assists re-establishment of the forage. There are some organic dairies in the region that are using cover crops to manage weeds, but need to work out strategies and cover crop types that work under their conditions. Farmers also use the cover crop for spring/emergency forage and tend to see its value as a feed rather than a way to improve soil quality. Drilling seems to be the exclusive method in this region.
