Pushing the cover crop envelope
Cover crops have many known advantages, including improvements in soil health and structure, limiting soil erosion and nutrient losses. But enterprising Iowa farmers are pushing the envelope, using seasonal cover to reduce weed pressure and herbicide use.
In western Iowa, Harrison County Farm Bureau member Brandon McHugh raises row crops, silage, Red Angus cattle and chickens on his sixth-generation family farm. Since the early 2000s, he has been putting cover crops on his fields in the fall.
“When we started, it was mostly to feed our cattle,” he said last week during Practical Farmers of Iowa’s Cover Crop Boot Camp in Ankeny.
In recent years, allowing the cover to grow in the spring has provided McHugh protection from weed pressure on corn-on-corn acres. “I still use a pre (emergent herbicide), but a lot of times, if you time it right, you can skip the post,” he said. “I started reducing herbicide use in 2015.”
McHugh uses glyphosate to terminate his cover and a generic broadleaf herbicide for preemergence.
Planting a cocktail
His mix this year was a combination of winter wheat at 30 pounds an acre, winter peas at 10 pounds an acre, tillage radish at 4 pounds an acre and balansa clover at 4 pounds an acre, which costs about $37 an acre, including the cost of having the seed flown on in the fall. He applied cover to 200 acres.
In the past, he has also used oats in place of wheat. The small grains combined with the peas are harvested in the spring as bailage, or cattle are let out to forage in the fields, depending on their feed needs.
“Right now, I’m really in an experimental stage, trying different (combination of cover crops),” he said.
One challenge McHugh noted was that this approach requires him to be more diligent about scouting fields for weed pressure. He then spot treats problem areas to protect his crop throughout the season as necessary.
In eastern Iowa, Washington County Farm Bureau member Michael Vittetoe, who produces row crops, cattle and hogs on his farm, has been working with rye on soybean acres.
“One of the things when you start looking at a system like this is you’ve got to have your own values and use those when making decisions on the farm,” Vittetoe said. “I’ve come to believe that we can have a production agriculture system that’s in sync with nature, which creates a healthy ecosystem, which creates healthy crops and livestock.”
Crimping the rye
His process is to terminate and crimp the rye in spring after planting beans between the rye rows. By laying down the rye residue, the ground between the soybean rows is protected until the rows close.
His 2021 costs for the system were about $82 per acre. He used 40 pounds of rye per acre, which he drilled in with his own equipment. Rye was the biggest cost, at about $30 per acre, followed by an Enlist post-application, which cost about $25 per acre. Using glyphosate for burndown was about $12 per acre, while the cost to run the rye crimper averaged out to about $15 per acre.
In an effort to reduce the per acre cost, Vittetoe’s plan for next season is to eliminate glyphosate burndown and move to only crimping the rye. He expects to still use a post-emergence herbicide in 2022 but is hopeful he’ll be able to eliminate that in the future as well.
“We saw very little weed pressure between the rows, even before applying post this year,” he noted.
Looking even further out, Vittetoe envisions a future where he is able to harvest the rye between the bean rows and sell it or use it to feed his cattle, providing another revenue stream. But ultimately, the soybean yield is going to be the deciding factor of which practices he continues to use.
Last year, in the worst cases, Vittetoe saw a 7 bushel per acre reduction in his bean yields due to rye reducing soybean plant growth. He believes refining and improving the practice will help those numbers in the future.
“I think the potential is there to have better overall profitability,” Vittetoe said.
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