Doug Bos is Assistant Director of Rock County Soil and Water Conservation District, where he has worked for 27 years. When he talks about cover crops, he is not only talking of programs, he is speaking of personal experience.

Bos grew up on a farm, the oldest of 6 children. The farm wouldn’t be able to support a second family, so he went to work at Hills-Beaver Creek Co-op and also provided agronomist services. But he still had farming in his heart, so he and his wife, Lynette Stensland, bought a 100-acre farm in Rock County in 1987. The terrain is fairly steep, and the previous owner had farmed up and down the hills. Some areas had significant erosion.

“The hillsides and knolls would barely grow a crop,” Bos says. The soybeans were short with few beans, the corn about 3 feet tall. “You’d look at it and ask whether it was really worth planting this ground. Overall, it was an average farm in yield; but those hillsides took a lot of the profit out of what it cost to put in a crop.”

Bos had no-till beans, but more was needed. About 8 years ago he took half of the farm — the most-eroded half — and put it in cover crops. The other half he continued to farm as he had before.

He was enrolled in the Minnesota Natural Resource Conservation Services’ Soil Health Initiative funded through EQIP (Environmental Quality Incentives Program). It was a 5-year program which required annual soil health field and lab samples.

“By the years 2 or 3 you still kind of question whether it is worth it, with the cost of the [cover crop] seed and planting, and changing your practices so you can gain benefit from the cover crops. By year 5, I was sold on it.," he says. 

Over the period of 5 years, both dry and wet years, Bos said they increased organic matter from 3 to 3.8, and increased the phosphorous levels from 11 parts per million to over 40.

“The change in organic matter started to affect water-holding capacity, so in the dry years those [once eroded] knolls had crops just like the rest of the field,” he says. “That’s what really made a difference in what we thought cover crops could do for the farm. It’s building the soil structure and organic matter, it’s holding water, it’s making nutrients more available, and a lot of it is because of what happens under the surface. With cover crops you’re adding organic matter on top, but it’s all that root development, the biological activity that happens under the ground.”

As for the cover crop, Bos has had the best results with cereal rye, but has also added canola and turnips to the rye with success.

“If possible, we like to plant our beans into growing rye, then terminate it with herbicide,” he says. “The corn we spray the rye before we plant.”

2-3 years ago Bos put the whole farm into cover crops. And this is the third year they planted no-till corn. There have been good results with the no-till corn.

“Those factors altogether have sold us on cover crops, and so have practices like no-till,” Bos says.

Bos has seen the benefits, but that doesn’t mean he advocates that farmers blanket their farms with cover crops.

“Every farmer’s situation is different,” he says. “So every farmer finds a way that will work for them. We suggest farmers take a small portion, plant it, and then compare it to their existing practices.”

That comparison on his farm persuaded Bos of the value of cover crops. The annual soil health sample which made it possible to track improvement in soil health was also an important convincer.

The NRCS and SWCD incentive programs help offset the cost of trying cover crops. The Federal Crop Insurance Corporation, which once did not look positively on cover crops, now also has a $5.00 per acre incentive to encourage cover crops.

But, Bos said, it still comes down to whether or not it is worth the effort and expense. In his experience, it definitely is.

“We have steadily increased our [average yield] using no-till and cover crops,” Bos says. “Looking back, in the very wet years of 2017, ’18, and ’19, we had some areas that before struggled to grow a crop and they were great, and we had 2 really dry years in ’21 and ’22 that it didn’t miss a beat on yields — especially on those eroded knolls. I think we’re accomplishing what we want to with this farm.”

Related Content: 

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No-Till, Cover Crops Improve Feed Quality, Limit Erosion and Build Soil Health,

Minnesota Grower Turns to Covers to Battle Erosion