New Resources and Lessons Learned in Grazing Cover Crops: Save Money, Build Soil Health

Interseeding cover crop into V4-V6 stage corn.

Wade Dooley is a sixth-generation farmer who operates Glenwood Century Farm in Albion, Iowa. Since 2015, he and seven other cooperating farmers in Iowa and Minnesota have participated in a grazing cover crops trial to dig into the benefits of grazing diverse cover crops with cattle. Wade and the other cooperators wanted to quantify just how much benefit they were getting out of grazing cover crops—and now that the project is complete, the results, and the lessons learned, are in.

Wade Dooley, right, speaking to field day participants about his cover crops.

Many of us are familiar with the benefits that cover crops can provide, such as reducing soil loss, conserving soil moisture and improving soil health. Livestock impact through grazing can accelerate those positive benefits, while offsetting the cost of winter feed. “It is the best and fastest way to realize an economic return on using cover crops while at the same time improving your soil conditions. You can’t go faster than with cows, as far as showing a net return on a single year cycle. Over 10 years, I think a cover cropper that doesn’t have livestock will still see major benefits, but not in a single year. If they’re worried about a one-year lease or a one-year return, they can show their banker: cows are the way to go,” says Wade.

So how much grazing should you expect to get out of a winter cover crop? Wade says, “Depending on the herd that we’re using, if they’re really easy and calm, easy to handle, and we’ve already got everything fairly quick to set up and tear down, I want a minimum of seven days of grazing.”

The equation may change if you are grazing another farmer’s row cropped land via a grazing lease. In that case, the costs of transporting cattle mean that you’d need more grazing days to break even. Bruce Carney, another project cooperator who operates Carney Family Farms outside of Maxwell, Iowa, says, “You would have to have, I would guess, a minimum of 30 days [of grazing] to haul cattle to somebody else’s farm.” Bruce’s cattle grazed on his neighbor, Rick Kimberley’s, cover crop, and since Bruce’s pasture is adjacent to Rick’s crop fields, the logistics of grazing were easier.

Bruce Carney speaking at a field day at his farm in Maxwell, Iowa.

Cooperating farmers in this project grazed an average of about 16 fall days and 8.5 spring days, though several farms surpassed 30 days for the full season. On average, net profits equaled $40 per acre.

Planting early enough to get sufficient growth before the weather turns too cold, particularly in the northern climes, was key to maximizing grazing days. Dr. Allen Williams, who has widely studied and utilizes adaptive grazing on his own ranch and has spoken multiple times at SFA events and conferences, says the secret is often interseeding before the cash crop is harvested, such as planting into corn in the V4-V6 stage. Allen says there are a number of planting options: “We can broadcast seed using a highboy, we can fly it on, or we can retrofit planters so that we can go in and drill in between corn rows.”

Cover crop growth prior to corn harvest.

But don’t be alarmed if cover crop growth slows when the corn canopy grows over the top of the newly-germinated cover, says Allen. “Many times you may think you have lost that cover crop, but it’s just lying dormant. Once that corn is harvested, if you’ve got proper moisture and soil temperature, then you see very rapid response. It won’t be long until you can get your livestock in on that cover crop.”

Farmers are using other creative ways to stretch the cover crop growing period, too, such as shorter-season corn hybrids, including small grains in their rotations, or even planting and grazing warm season covers in place of cash crops in some years, which can more fully leverage any investment made in fencing or watering systems. Fundamentally, some cooperators said, this requires a shift in thinking about the value of cover crops. “Until you start looking at your cover crop and give it the same importance as you do your cash crop, you’re not going to get the full benefit out of your cover crop. It means flexibility. It means maybe changing hybrids and using shorterseason hybrids to let your cover crop grow longer to get more benefit out of it,” says Bruce.

Overall, Allen says that grazing provides opportunities to further bolster the soil health benefits from cover crops: “You’re actually creating a double benefit. You can not only create more net revenue in that year than your cash crop generated, but you’re putting money in the bank for the future because you are creating soil benefits that last for years and years after that.”

Dan Jenniges, who spoke at the 2017 Midwest Soil Health Summit, with a diverse cover crop mix on his farm.

Still, starting small might be a good way to get started and begin seeing results on your own farm. Dan Jenniges, another project cooperator who manages Jenniges Hidden Acres in Pope County, Minnesota, stresses that much of what he learned, he learned from experimenting: “It can be as scary or as comforting as you want. It can be as simple or as complex as you want. Never feel bad about trying one particular cover crop on a small area to get your foot wet.”

You can learn more from the experiences of cooperating farmers in this project, as well as other experts like Dr. Allen Williams, by downloading “Grazing Cover Crops: A How-To Guide” or by viewing our Grazing Cover Crops Video Tutorials.

This project was led by the Pasture Project along with Practical Farmers of Iowa, Sustainable Farming Association, and Land Stewardship Project.