For farmers who grow small grains, the harvest is just the beginning. After harvesting the crop in July, the possibilities for cover crops to plant on that ground are endless. “The world is your oyster,” says Jon Bakehouse of Hastings. Because you can seed cover crops as early as July 1, there’s plenty of time for those plants to soak up the long, hot days.
Cover crops such as radishes and turnips—in most years—would not provide much benefit if planted in late fall between corn and soybeans. But it they are planted in the summer, they would have time to grow and develop large tubers and bust up soil compaction layers. Likewise, there’s an advantage for legumes if they are seeded in summer. They would have more time to fix plenty of nitrogen in soil.
Another advantage of seeding forages as cover crops in the summer is it gives them more time to produce plenty of biomass. This gives livestock farmers the option to rest perennial pastures in order to graze them later in the fall or to stockpile for winter, cutting back on hay costs. In this week’s episode of Rotationally Raised, we talk with farmers who plant multi-species cover crop mixes in the summer for their cattle to graze.
Grazing summer-seeded cover crops
Paul Ackley, farming at Bedford in southwest Iowa, relies on a summer-seeded cover crop mix to cut his hay cost and feed his cows economically through winter. “This fills the gap in the winter when we would be feeding hay. The cattle really do well grazing these covers,” he says. “Their health is really good, they’re happy, they’re finding their own meal.”
He uses rotational grazing. “We set up polywire electric fence, fencing off enough of the cover crop to last the cattle for three or four days of grazing. So we move the fence for them every third or fourth day—to give the cattle a new area of cover crop to graze on.”
He follows the cover crop mix with corn in his rotation to take advantage of the manure from the cows, so he also includes nitrogen-fixing plants in the mix.
Root diversity to improve the soil is a big consideration for Jon Bakehouse when considering species for his cover crop mix. “Get something on there that’s growing aggressively, and at different rooting depths,” Jon says. “With our corn and soybeans, they’re very shallow rooted crops, so if we can get something that has a taproot drilling down, I think that’s a benefit.”
Cover crop roots do the work
He says that all those different types of roots create more channels for water to infiltrate, helping to cut down on the amount that runs off the surface. He says he also wants to have warm-season and cool-season plants to provide different types of rooting patterns under different weather conditions.
Tim Sieren of Keota agrees. “Each plant has its own conditions,” he says. “One plant will take advantage of warm weather, and another will do better in the cool season.” Last year after harvesting his rye crop, he planted a mix of grasses, legumes and brassicas. One of the legumes he planted, a cowpea, didn’t respond well to the wet weather he had on his farm in August.
“It’s just kind of an insurance policy, to have a mixture,” he says. “If you’d have put all cowpeas in here, you’d have bare ground.” But, because he planted a mix of rye, radishes and rapeseed in addition to cowpeas, he had a good cover. “One of them will take advantage of the conditions,” he says. He says it also helps soil microbes to have different species growing together: “Some microbes like some plants better than others.”
Benefits of crop diversity
Next week, we’ll wrap up this 2017 series of Rotationally Raised articles and videos, with our 12th and final episode. We’ll hear from farmers about why consumers need to understand the benefits of crop diversity and crop rotations. That understanding will help consumers support food and agriculture products that benefit farmers and rural communities. And also benefit the soil that these communities and farmers tend to and protect. For more information on small grains, check out practicalfarmers.org/small-grains.
Editor’s Note: Ohde is the research and media coordinator for Practical Farmers of Iowa.