No-till and cover crop systems cut costs and save soil
No-till/cover-crop systems are proving their worth in Redwood County, Minnesota, where corn and soybean growers who practice no-till and plant cover crops reported a net profitability in 2018 of nearly $113 per acre, while conventional-till producers earned a net return of just $5.25 per acre.
While yields under both management systems have stayed the same or slightly increased with no-till and cover crops, cost savings with no-till account for the lion’s share of the increased profitability.
“Cost savings result from reduced tillage, but also from a reduced need for herbicide and fertilizer,” says Jennifer Hahn, watershed planner for the Redwood Soil & Water Conservation District. “With no-till, the cost for labor is less; there’s less cost for custom hire; fuel costs are less; and there’s less wear and tear on equipment. Also, because you’re using less equipment with no-till, there’s less depreciation. A no-till/cover-crop system balloons into a variety of cost savings.”
With an eye on helping producers document the potentially greater net profit to be realized from a no-till/cover-crop system, Hahn developed a spreadsheet that functions as a Profit Zone Manager program. Conventional-till farmers as well as no-till/cover-crop growers use the spreadsheet.
When looking solely at soybean weed-control/seedbed-preparation, costs for no-till/cover-crop growers in 2018 were half of the costs incurred by conventional-till growers.
Conventional-till growers relying on two tillage passes in the spring incurred a per-acre cost of $15 per pass.
The no-till system, of course, incurred no spring-tillage costs, but did incur a $5-per-acre cost for rye seed and $4.67 per acre for Roundup to terminate the rye.
The no-till system also incurred a cost for postemergent herbicide of $19.48 an acre, as did the conventional-till system.
However, the no-till system did not incur the cost for preemergent herbicide of $10.13 per acre, which the conventional-till system incurred.
With no-till, the rye cover crop reduces the need for a preemergent herbicide.
All told, costs for weed control and seedbed preparation for the conventional-till system came to just under $60 an acre, and just under $30 per acre for the no-till/cover-crop system.
At harvest, the no-till/cover-crop soybeans yielded 8.83 bushels per acre more than the soybeans produced by conventional tillage.
Given a soybean price of $9 a bushel and half the cost for weed control and seedbed preparation, the economic advantage for the no-till/cover-crop system came to $110.56 an acre. (These figures reflect 2018 prices.) Yet the economic benefits from practicing no-till and growing cover crops are not necessarily automatic for a newcomer to the system.
“Sandy soils work well for no-till, but a lot of our soils are heavy clay,” says Hahn. “When these have been tilled for a long time, they have little structure left and become compacted. It’s difficult to practice straight no-till. Though reduced-tillage practices can be effective until some structure returns to the soil, then making no-till a more viable option.”
Small Scale Slices Risk
Experimenting with no-till and cover crops on a small scale takes away the risk of a farm-scale failure.
“I encourage farmers to experiment with no-till and cover crops by starting small, perhaps planting side-by-side field comparisons,” says Brian Pfarr, no-till farmer and resource specialist with the Redwood Soil and Water Conservation District. “That lets you experiment with something new in an environment where soil and moisture conditions are the same.”
He encourages farmers to be creative about finding ways to experiment with no-till and cover crops before making a farm-scale commitment.
“For instance, our local co-op offers no-till drilling on a custom basis,” he says. “And often neighbors with no-till equipment are willing to help out neighbors who just want to experiment with a small acreage.”
An existing line of equipment can sometimes work for experimenting on a small scale.
“A lot of planters can be modified to plant into green, standing cover crops,” says Hahn.
Pfarr, a corn-and-soybean grower, began incorporating no-till and cover crops into his own operation 10 years ago. In the early years of his transition, side-by-side field comparisons showed him that with fewer tillage passes his net income increased by $50 to $100 per acre without reducing yields.
His early efforts at growing cover crops included planting multi-species covers. But for simplicity’s sake, he evolved a system of growing only cereal rye every second year.
“After harvesting the corn, I plant cereal rye in late October or early November,” he says. “It comes up in the spring, and I plant soybeans into the green cereal rye cover crop. After the soybean harvest, there’s enough rye residue to keep the ground covered until we plant corn the following spring.”
Water infiltration rates in his clay loam soils have increased more than fourfold. “When we started, some of our tougher fields could only handle 0.9 inch of rain before water runoff started occurring,” he says. “Now those fields will take 4.3 inches of rain before runoff occurs.”
Increases in soil organic matter are also occurring.
“In the last four years our organic matter has increased by 1.3%,” says Pfarr.
The new organic matter translates into direct out-of-pocket savings. “The fertility from every 1% increase in soil organic matter provides the equivalent of 20 pounds of nitrogen per acre,” he says. “On my farm, I used to apply 180 pounds of N per acre. Now I’m down to 135 pounds of N per acre. That’s a savings of more than $20 per acre.”
Increases in soil organic matter go hand in hand with enhanced biological activity in the soil.
“As the microorganisms in the soil increase, they make nutrients more plant available,” says Hahn. “These benefits increase over time.”
While soil building is inherent in a no-till/cover-crop system, its ability to save soil from erosion is perhaps its greatest hallmark.
“On average, in the state of Minnesota, soil lost to wind and water erosion from conventional-till systems amounts to 5.2 tons per acre per year,” says Hahn. “This does not include soil lost to gully erosion. With a no-till/cover-crop system, that amount of soil loss is reduced to just 0.1 tons per acre per year.”
Aside from the high social cost of soil erosion and its concurrent reduction in long-term productivity for the farm, erosion causes direct out-of-pocket annual costs to farmers.
Eroded soil removes a significant amount of nutrients from the farm, says Hahn. Lost annually with eroded soil are 14.6 pounds per acre of nitrogen; 65.7 pounds per acre of phosphorous, and 21.9 pounds per acre of potassium. “The value of those nutrients lost to erosion amounts to $45 to $70 per acre per year,” she says.
Decreased Soil Losses
Soil losses in Redwood County could be decreasing as more and more farmers adopt no-till and cover crops.
“Fifteen years ago, on my drive to work, I wouldn’t have seen a single cover crop field,” says Pfarr. “Now I see as many as 12. In areas of the state where there are sandier soils, 12% to 17% of farmers are adopting no-till and cover crops.”
On his own farm, Pfarr looks forward to a future where no-till and cover crops lead to continuing health in the soil, more organic matter, and higher infiltration rates. He’s confident such improvements will continue building profitability in his operation.