Cover crop seeds take to the air
Cover crops have been around as a sound cropping and soil health practice for years. But in the past few years, they’ve been steadily growing in popularity throughout the Midwest. The practice would probably be growing faster if there wasn’t so much head-scratching about how to get seed established in fall.
Jamie Scott, Pierceton, Ind., says flying cover crops on works best for him. He and parents Jim and Cathy use cover crops on all 2,000 acres of their no-till corn and soybeans. The three were named national Conservationists of the Year in 2008 by the American Soybean Association.
“We drill about 200 acres, but that’s about all we can get done in a timely way after harvest. So we use an airplane to fly on the seed for 90% of our cover crops,” Jamie says.
60,000 acres flown on
After studying and testing cover crops for several years, Jamie, a strong conservationist, became a believer in their benefits. He’s not only recommending cover crops to neighbors, he’s using his experience to help them get the seed established. He now spends about two months a year arranging aerial seeding on more than 60,000 acres for cover crops in northeast Indiana.
Aerial seeding is still new to many farmers. Scott handles the details — like finding a local pilot and airstrip, and getting the seed to the airstrip with an auger truck or large seed bags for fast loading.
“With 60,000 acres of cover crops in our group, we can get some leverage in seed costs,” Scott says. “An organized group is a good way to go.” Their average cost for annual ryegrass seed this year was 75 cents a pound.
Time is money, especially with aerial application. “Fast loading and loading at a strip near the field are keys to affordable aerial application,” says Don Wirth, an annual rye seed grower in Oregon who works with Scott and others to expand the use of cover crops.
“There has to be a close working relationship between the pilot, the seed provider and the grower to make this work,” Scott says. “You want to take away downtime for loading, and avoid long distances between the strip and the field to be most cost-effective. It’s the pilot’s job to fly, and our job to make it most economical.
Seed in early September
“We want our cover crop established and growing in corn before it’s harvested,” Scott says. “In corn, there’s actually a big window for seeding dates, from August through mid-September. Our average fly-on date over the years has been Sept. 7.” His average seeding date for drilled rye has been Oct. 7.
“With drilled cover crops, rye roots grow to about a foot deep. But with the extra month you get with fly-on, ryegrass roots can grow to 3 feet or even close to 5 feet deep,” Scott says. He adds that the most successful cover crops come after an early corn harvest, which allows the cover crop to get sunshine for maximum growth before winter.
While he says there’s no doubt a cover crop pulls moisture from soil, Scott knows the value of decayed deep roots. The channels created help more rainfall infiltrate, and allow corn roots to more easily grow downward.
“You have more access to soil moisture and nutrients with cover crops in the cropping system,” Scott says. “Most people think the value of cover crops is the growth aboveground, but to me the real value is in what happens belowground.”
The Indiana group uses three planes. Each plane can seed about 1,500 acres daily. A diffuser underneath the plane disperses seed from a hole in the bottom of a hopper. The prop wash of the plane blows seed 60 feet to the rear. The seed’s swath, or width, depends on the seed type, wind and height off the ground.
“A plane flying 30 to 40 feet off the ground might give you a 55- to 60-foot swath,” Scott says, “but I really recommend you lay a tarp down and do a test flight over it at the height the pilot will fly to check your dispersal pattern.”
Scott says seeding rates are higher for aerial seeding (25 pounds per acre of an 80/20 rye and crimson clover mix) than for drilling (15 pounds per acre) or high-boy seeding (20 pounds per acre). But the application costs per acre are lower for aerial seeding ($11 to $13 per acre) compared to drilling ($14 to $16 per acre).
Scott has tried helicopters in the past, but has much better luck with a plane. “I’ve tested helicopters, but the rotor causes an uneven seed pattern. We’ve found it difficult to get light seed beyond the downdraft of the tip of the blades.”
Best stands in corn
“I can’t put my finger on it, but for some reason we’ve had better cover crop stands in corn than in soybeans, especially in the first year of cover crops in soybeans,” Scott says. “I’d definitely recommend first-timers try cover crops in standing corn first. One question most people have about corn — a question we had, too — is whether seed gets caught up in the corn whorls. But we’ve found that’s not a problem.”
Scott has also overseeded using his highboy sprayer rig. “The advantage is you don’t have to worry about the wind or obstructions like wind turbines,” he says, “but the downside is you get some compaction and some trampled crops.”
Betts writes from Johnston.
This article published in the August, 2012 edition of WALLACES FARMER.