Kristin Duncanson and her husband, Pat, have been farming near Mapleton for the past 38 years. For the past 12 years the family has also been planting something a little different. Cover crops.
Cover crops are a mixture of seeds that grow quickly and are planted in the fall after other crops have been harvested. They’re planted, “winter over,” and then grow in the spring. If things go just right, they’re the first greenery to pop up in the springtime.
Farmers have two options when it comes to cover crops: leave them and plant into them, or terminate them before spring planting.
“When the snow is melting and we’re seeing added moisture, we have the opportunity with these cover crops to help prevent erosion events,” Kristin Duncanson said. “In spring, when we still have frozen ground and then melting and movement occurs, those planted cover crops allow the topsoil to stay put.”
The same is true with windy days. When the snow melts, exposing the soil, farmers want to prevent the soil from blowing away.
Duncanson said that cover crops are used to keep the soil healthy so spring planting can be done as early as possible. Healthier soil and fluffier tilth mean the soil will remain and the water will drain properly, drying the fields more quickly than they would without the use of cover crops.
In fact, last Memorial Day when the weather was windier and warmer than usual, Duncanson noticed that all the family’s fields that had cover crop didn’t have a loss of soil, unlike the fields around them that weren’t covered.
“We’ve been able to visibly see that our fields aren’t blowing, which is great,” Duncanson said. “Then there’s the winter months. When we have cover crops on our fields during that time, we can have no snow on the fields and they’re still not frozen because they’re covered with the crops. We’ve also seen a reduction in blowing on those fields, too. The bottom line is we’ve seen, and so have our colleagues, that this works. Cover crops get the desired outcomes.”
Forty-five years ago, Duncanson’s father-in-law was experimenting with his own type of cover crop by planting bromegrass after fall harvest. Over the past decade, the Duncansons have relied on their own cover crop to help replenish the soil at Highland Family Farms.
Duncanson said there’s not yet a step-by-step process to follow due to different factors, like slope, soil and where cover crops are planted, but that’s what research and development are for.
“You have to be willing to experiment a little,” Duncanson said. “That’s where you have to look at science and the data that’s out there. Science has already proven that cover crops are good for the land. They help with soil to build organic matter and soil tilth and therefore the yield is increased over time.”
In Minnesota, the period between harvest and freeze up is short, so Duncanson said cover crops rely on a different method of thinking.
“Our neighbors think we’re doing proof of concept on different things all the time,” Duncanson said with a laugh. “You have to be willing to do it. We rotate crops, just like you do with manure application. It does take time to show the benefit of cover crops, so there is a risk, and I think that’s a huge barrier for other farmers.”
With cover crops still being relatively new in the area, Duncanson has found helpful resources through various extension offices, universities, the United States Department of Agriculture, National Resource and Conservation Services and agronomists. Until there is a larger set of data, it’s tough to stick to one decision when it comes to planting cover crops.
“We’re blessed with the fact that we do have a great network of like-minded farmers across the country that are also planting cover crops,” Duncanson said. “It’s nice to reach out to them and say, ‘What did you plant, and did it work?’”
Along with the traditional cover crop mixture, the Duncansons have also dabbled with planting cereal rye, which the farming family has, surprisingly, found to be a beneficial weed deterrent.
“Weeds apparently don’t like rye, so that’s promising,” Duncanson explained. “We’re still in the proof-of-concept phase, but this is our third year of growing rye, and so far, it’s going well.”
After their cereal rye cover crop is out of the fields, a portion of the product goes to mills, while some goes to distilleries, Duncanson said.
“Cereal rye isn’t something you can just haul to the co-op,” she said. “You have to be creative with it, which is why we thought of the distilleries. Anytime I’m in different areas for work, I’m dropping samples off. I just keep rye samples with me in my car. Working with cereal rye has been fun and new.”
A test field comparing strips of tilled land versus cover crop areas on Highland Family Farms.
To Duncanson, the decision on whether to plant cover crops, like cereal rye or the more traditional non-grain mixed option, is an easy yes, because it allows for less sediments going into ditches or runoff and there is little to no wind erosion. The result is better organic matter and nutrients that stay within the soil.
“The bottom line is that there just aren’t enough farmers utilizing this practice,” Duncanson said. “Yes, we have an obligation to ourselves to be profitable, but we’re also stewards of the land, water and community. Farmers do a lot of great work, and we just don’t hear about this practice from the collective. We’re hoping more people start to look towards cover crops to understand why it’s important to not only their bottom line, but to the water, streams and soil, as well.”
Though less expensive to plant than traditional crops like corn, soybeans and wheat, there is still a cost to cover crops. Depending on the cover crop that is planted, the price can range anywhere from $10 to $110 per acre. The cost varies based on where it’s planted and how many species are within the specific cover crop.
“It’s less expensive than traditional crops, but it’s still an expense because you have to make another pass with equipment and there’s also labor costs,” Duncanson said. “You have to be strategic in what you’re planting so over time you can see what it does to your bottom line in terms of bushels and production.”
When Highland Family Farms first started planting cover crops, Duncanson said they almost immediately saw a positive increase in growth and profitability, yet at other times it took a few seasons for the cover crops to pay off. The reasons for this discrepancy are differences in topsoil, crops and weather.
“Overall, for us, it’s been profitable,” Duncanson said. “Our productivity is higher, and we’ve even minimized some passes over our fields because of reduced tillage.”
Duncanson draws a comparison between the current use of cover crops and earlier times when much of the land was prairie and covered with tall grass.
“It’s the mindset that we know that prairie grass acted as a great filtration system and stabilized the soil,” Duncanson said. “Now, it’s a coming of age to say, ‘Here’s the issue, and how can we work together to enhance this practice.’”
As she was driving around this spring, Duncanson recalls feeling anxious when driving past fields that didn’t utilize cover crops.
“I just didn’t like seeing how many fields were being tilled to completely black,” Duncanson said. “It reduces the nutrients because all of it is just blowing away. The biggest thing is, we would just like other operations to try cover crops, too, so they can see how well they work.”
Duncanson said Southern Minnesota farmers do a good job of managing their waterways, but acknowledges that there’s more to be done.
“We don’t have all of the answers, but we’re trying different things out and are definitely willing to talk. Just try it,” Duncanson said. “Start small and seek technical and science-driven information.”
Photography by Jonathan Smith