Some farmers want to try a new idea on a few acres to evaluate it before using it in a big way. Not Robert Harvey––at least when the idea is cover crops. The Guthrie County, Iowa, farmer went all-in on cover crops two years ago, seeding cereal rye on all 1,100 acres he farms with his father, Gerald.
He credits research as well as incentives by the National Resources Conservation Service (NRCS) and the conservation district for taking his decision over the top. “I got interested in cover crops more than four years ago after reading about their benefits," the no-tiller says. "I was leaning toward trying them when I went into the soil conservation office to update my conservation plan. Conservationist Jason Hart mentioned that the NRCS was offering a disaster incentive through the Environmental Quality Incentives Program (EQIP) after the drought in 2012.”
The $32-per-acre EQIP incentive helped Harvey make up his mind to start with covers right after the 2012 drought. "Once Dad and I saw cover crops work that first year, we committed to growing cover crops on all the land we own," Harvey says. "On our rented acres, I base the decision on whether to use cover crops on how long I might have that land."
No-till experience helps
Terminating cover crops isn’t really an extra expense, Harvey says. “As a no-tiller, you like to kill all the weeds that are growing before you plant. We use 24 ounces of Roundup. While it’s not an extra expense to kill the cover crops, the timing can be a challenge,” he notes. “You need warm weather for a good kill—at least 40 degrees for two nights before and two nights after you spray Roundup. That can be difficult to accomplish in early April.”
On the other hand, he says that long-time no-tillers don't get quite as nervous about terminating cover crops because they’re used to killing weeds. “I’m looking at other herbicides now, and next spring I’ll experiment with them,” he says.
While cover crop termination can delay planting, a no-till and cover crop combo can shorten it. "We drive out in the field sooner because the soil is more solid with cover crops," Harvey says. "At the same time, the soil is more mellow. I think no-till over a number of years helped with that."
Control erosion, build organic matter
Harvey, who has practiced conservation for years, says controlling soil erosion and building organic matter are the two primary reasons he is using cover crops. He also likes the idea of not contributing nitrates to the South Raccoon River, a source of drinking water for Des Moines area residents.
Like his grandfather, Harvey aims to have his soil in place for a long time and believes cover crops will play a big role in keeping his sloping land protected against soil erosion. "The terrace Grandpa Hallett built in 1949 is still here," he proudly points out.
Harvey also has CRP wetland along the river, riparian tree plantings, and contour buffer strips. He built a number of waterways and uses grass turn strips on steep end rows on his 7–12% slopes. With the extra soil erosion control offered by cover crop roots and top growth, he hopes to replace some smaller waterways and grass turn strips.
Logistics of cover crops
Harvey is experimenting with cover crop mixes on small areas. He’s tried hairy vetch with cereal rye, rapeseed with rye and radishes with rye, cutting the rate of cereal rye in half for each mixture. “Cereal rye seems to be the easiest thing to get started. It’s been tough to get a stand with radishes—I got a good stand with hairy vetch and rapeseed last fall but our cold winter killed them,” he says.
It cost Harvey $41 per acre to get 65 pounds an acre of cereal rye flown on each of the last two years. “Sharp Flying Service out of Indianola flies it on the first week of September, on both standing corn and soybeans,” he says. He hasn’t changed seed populations or his fertilizer program; he takes soil samples on a 2.2-acre grid and applies variable P and K.
“I put on half the nitrogen as anhydrous pre-plant, and half as early sidedress,” he says. “I use 6/24/6 starter fertilizer in the furrow at 5 gallons per acre.”
No risky business
“I didn’t feel like I was taking a risk when I planted all the cover crops two years ago,” Harvey says. “If you’re already no-till, you have a mindset that works well with cover crops. I was just never concerned with getting the cover crop terminated. That seems to be a big issue with the guys who till.”
Harvey says it's too soon to draw definite economic conclusions about cover crops, especially when it turned hot and dry in the middle of summer last year. “I don't think I can put an economic value on cover crops until I've used them for four years," he says. "By that time, I'll have gone through enough rotations and variable weather to judge the economic returns. In the meantime, though, I know I'm advancing the rate of organic matter buildup. They also work so well for erosion control I know I’ll stick with some kind of protection. For that reason alone, more farmers ought to be setting a field or two aside to try cover crops."