The economics of cover crops have to make sense, but Mike Jackson says the best feedback comes from the soil itself.
“We try to keep the soil alive,” Jackson, a Mahaska County Farm Bureau member and former chair of the Iowa Farm Bureau Young Farmer Advisory Committee, said at a field day on his farm in late November. “It’s nice to be able to turn a shovel of dirt in the spring and it looks like coffee grounds.”
Jackson, who farms with his dad, Mark, has seen changes in his soil biology since he started planting cover crops six years ago. He’s found more earthworms and increased soil biological activity that are improving the soil aggregate on the family’s farm east of Oskaloosa.
They also keep track of the numbers that matter like cost, biomass growth and yield differences for their cash crops.
“We are farming for a living. We’ve got to make everything pencil out,” Jackson says. “We always evaluate what we do at the end of the year. That’s how you learn, and that’s how you grow.”
It hasn’t always been easy, he admits. With corn and soybean prices hovering near the cost of production, farmers naturally question the additional cost and management that cover crops require.
But, Jackson says, seeing an armor of green cover crops hold his soil in place during heavy spring rains reaffirms that they’re doing the right thing.
“This spring was a great reminder,” he says. “My soil is still on my farm. It’s not in a ditch or in a neighbor’s field.”
That’s part of the reason the Jacksons plant cover crops on “every acre, every year.”
There’s no single right way to plant or manage cover crops, Jackson points out. He uses a John Deere grain drill for seeding cereal rye, but other neighbors are hiring aerial applicators or using a fertilizer spreader. He’s also experimented with different seeding rates through Practical Farmers of Iowa trials.
“It’s more of a mindset of doing what works for you,” Jackson says. “What works on (his neighbor’s farm) might not work great for me.”
One step at a time
Mark Jackson advises first-time cover crop users to be cautious. He notes that it’s easier for new users to manage cover crops before soybeans since they are less sensitive to competition than corn. Taking things one step at a time can produce big changes over a lifetime of farming, he says.
“If you want it to work, it will work. Give yourself three to five years. Don’t give up the first year, and don’t give up the second year,” Mark says. “I come from the generation where my father plowed everything. Now I’m planting into cornstalks and waist-high rye.”
In addition to soil quality gains, the Jacksons have been able to reduce herbicide use in some cases because the cover crop biomass suppresses weeds.
Grazing cover crops
Many cattle farmers are also finding cover crops a good fit by providing an additional feed source while improving the soil, according to Jason Steele, a Natural Resources Conservation Service (NRCS) soil scientist who spoke at Jackson’s field day.
“They work together quite well,” he says. “If you have cows and you’re not using cover crops, I think you’re hurting yourself.”
One southeast Iowa farmer Steele works with brought some color back to his soils by planting a multi-species cover crop mixture over several years along with cattle and hog manure applications. The improvements have brought earthworms back to the soil and led to 200-plus bushel corn yields on a field with a corn suitability rating (CSR) in the 50s. His neighbors are starting to take notice of the yields as well as the erosion control provided by the cover crops, Steele says.
“He gained those yields by doing cover crops over the years,” he notes. “He’s making it work. He’s making money at it, and he’s one of the happiest farmers I’ve talked to all fall.”
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