Cover Crops

In the past few years, Western Iowa has had above-average growth of cover crop acreage compared to the rest of the state. (

(KMAland) -- The Soil Health Partnership’s Cover Crop Planting Report shows that farmers are using diverse strategies to plant cover crops and a variety of plant species to accomplish their soil health goals.

The Soil Health Partnership is the flagship sustainability program of the National Corn Growers Association. They conducted a detailed survey on cover crops with more than 80 farmers across 11 states in the Soil Health Partnership network about cover crop usage on their trial sites in the fall of 2019.

Maria Bowman, lead Scientist for the Soil Health Partnership, says the report provides farmers some highly requested data.

“SHP is really trying to provide some context to farmers about what other farmers are planting to get some information out there about cover crop usage, and about the costs of those practices. We think that farmers are really trying to understand both the costs and the benefits of cover crops on the farm. And in order to do that we need to collect some data to get a better understanding of what types of cover crops they are working with and some of the challenges for those practices.”

Bowman says there were some surprises in the data.

“Although most farmers plant their cover crop after they harvest their cash crop, we actually had 25 percent of the farmers that responded to our survey interseeding or overseeding that cover crop into a standing cash crop. I think that was surprising to us. You can also see this in the range of planting dates that farmers reported. Although, more than half of farmers planted between the middle of September and the beginning of November, almost 40 percent planted before or after those dates. So, some of those folks are the ones that are getting really creative in terms of how they get that cover crop out there to deal with timing or labor constraints, particularly as you get into those northern latitudes.”

The most widely planted cover crop species was cereal rye. Of the farmers who planted a single species, 80 percent planted cereal rye, and it was also present in 50 percent of cover crop mixes.

The survey also asked farmers how much they were spending on cover crop seed and how much they spent on planting cover crops.

“We know there’s a lot of variability in how much they’re spending to get cover crops in, so we were super interested to see what those numbers looked like across our network. The medium cost of cover crop seed in our network was $15 an acre, and the cost to apply it was $12 an acre. But, for farmers planting more diverse mixes, say more than three species, they were spending more like $22.50 an acre, compared to single species average out at about $14 an acre.”

Bowman says the report shows farmers are seeing the benefits of cover crops.

“There are a lot of reasons farmers plant cover crops. Sometimes they’re concerned about water quality, sometimes it’s environmental benefits. So, they have a lot of really diverse motivations for planting cover crops. But, clearly we’re seeing the impacts in terms of improving soil health over time, we’re seeing those changes in the soil health indicators. Aggregate stability is one that can be really valuable to farmers. As you change that soil structure it can make it easier to get out there and work in the soil. We’re hoping to document some more of those impacts in terms of long-term resiliency, but definitely our farmers are seeing the short-term benefits. Weed control, as well, is another one that we hear about a lot.”

Find the complete report online at

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