Covering the basics: How to get started with cover crops in Wisconsin

If you're a farmer looking to get into planting cover crops, it's easy to start out in the popular sustainability practice, say Wisconsin farmers Ken Rosenow and Jim Isermann.

The two were featured on a recent episode of Dairy Stream, the sustainable farming podcast produced by the Dairy Business Association and Edge Dairy Cooperative and sponsored by The Nature Conservancy of Wisconsin.

Rosenow owns the small family farm Cedar Home Farms in Oconomowoc, while Isermann farms in Wisconsin and Illinois as a field manager of the Soil Health Partnership, a farmer-led coalition to adopt better soil practices. Both have extensive experience in using cover crops.

Isermann said his group promotes soil health through on-farm research, and that has a lot to do with cover crops as they help retain soil and its nutrients. He said SHP does comparative trials with growers to collect data and help them find a cover crop system that works for their farm, with growers committing to a five-year trial period. They also do outreach with local watershed groups, he added.

"We work with growers who try to adopt a new soil health management system, oftentimes as cover crops," Isermann said. "(We) take a look at the soils, the economics, the management and agronomic information coming off that farm. We try to look at it over time, so most of our growers are committed to a five-year trial with our program."

Rosenow said his farm is a "family partnership" with his wife and children. The farm is 1,000 acres with 900 crop acres, where they grow corn, soybeans, wheat and hay. Rosenow has been planting cover crops for almost seven years. As his land is located in "lake country," he uses cover crops for cleaner water.

"We have land in Jefferson and Washington counties, and a lot of where we live is commonly referred to as 'lake country,'" Rosenow said. "One of the big benefits of cover crops ... is keeping the water clean. We have a lot of urban neighbors and friends here and we just like to make sure we have all the same values that they do."

Isermann added that other benefits of cover crops are the ease of planting them in tight spaces where cash crops wouldn't normally grow, and they also reduce erosion and retain soil nutrients. He said they also do a good job of nutrient recycling and can even produce forage for livestock if planted the right way. 

The most popular cover crop, according to a survey of growers in the SHP network, is cereal rye, Isermann said. That's because it's very hardy for winter and can be planted late after harvest and still hold soil and nutrients in the ground.

Other popular cover crops are those that winter-kill, where instead of surviving throughout the cold season like cereal rye, it dies and leaves behind a mulchy surface covering that protects the soil underneath until planting season comes around. Oats, forage radishes and field peas can accomplish that, although options become limited as you move further north, Isermann said.

"Unless you're looking at a scenario of small grains, or corn silage, or some kind of unique opportunity to be able to get those covered earlier, it becomes a little more difficult as we get into (the) Wisconsin area," Isermann said. "If you can get it out on the ground, one way or another cereal rye tends to grow, and it will be there come springtime to give us some benefits."

Rosenow's neighbors have planted radishes as cover crops and have had major success over the years, especially on no-till or limited tillage farms. Even as farmers get more skilled and start to mix cover crop species, he said radishes are still included in those mixes, even with the different kinds of soils found in Wisconsin.

"I think we do have a lot of no-till farmers, that's pretty big around here ... and radishes were very popular and that you could plant them and let them, so to speak, do the plowing for you," Rosenow said. "A lot of people still are incorporating some radishes in their mixes. But ... the cereal rye really does take precedence a lot more because it's easier to do."

Keep mixes simple, Isermann said, by only including two, three or four different species of cover crop seeds because the costs can rack up quickly and it might be difficult to access other species depending on where you are. Wheat, barley and legume cover crops are also good choices for mixes, he said, especially if you plan on planting after harvest.

Rosenow said he uses a few different planting methods and has often improvised, but he most often uses helicopters to plant seeds and a fertilizer spreader. He's also used a no-till drill. He said farmers should always be flexible, though, because some things just might not go according to plan and seeds or supplies might get more expensive the next season.

In his experience, Isermann said the average cost per acre for growers is $15 for the seeds and $12 for the application, but farmers with a lot of experience may find the right multi-species mix for them and be willing to pay out more if they have a good plan for their cover crops. He said those costs can reach over $20 an acre just for seeds.

"As we started to apply more complex mixes, the cost went up and we got closer to a grower putting out a three-way mix or higher, they might be in about $22 (per acre)," Isermann said. "But they're also in situations where they knew that that cover crop was going to express itself. They were usually being able to seed earlier, maybe using some of the summer annual mixes, so they were willing to throw more money into it."

Isermann said he hopes planting cover crops for the first time serves as a learning experience because many mistakes are commonly made, but they have to be made in order to get better at it. He said one of the most common problems is planting a cover crop at the wrong time of the year. Isermann also noted that farmers mistakenly plant cereal rye in fields where they plan to plant corn next season – that can have serious implications for nitrogen concentration.

"If your intention is to plant corn into that rye next year, you really do need to understand particularly the nitrogen management implications of that and making sure that you're set up to deal with that successfully, because that can be one that can come back to cause some issues for growers over the years," Isermann said.

Planning ahead pays in dividends, Rosenow said. He explained that with a small labor force and a big harvest ahead of them every fall, there's only a small opportunity to plant cover crops in between seasons. He said it's important to "roll with the punches" and leave all options on the table.

Farmers should consider talking with the Midwest Cover Crop Council, the Natural Resources Conservation Service or other local farmer-led groups for help on what to plant and when. Both Isermann and Rosenow recommended finding financial help through the NRCS. What helps the most, they said, is being able to do everything you can with what you have.

"We have improvised on all different ways of doing it," Rosenow said. "In the new group that we're forming right now in Waukesha County, one of the things we are looking into using some of the funds ... is to possibly buy or get a machine built that will be able to plant cover crops between the cornrows."