Flexibility and timing are critical to getting a cover crop established during the available window of opportunity.
To plant a cover crop with a drill in the fall, weather and harvesting delays don’t always provide time to get a cover seeded early enough to ensure good establishment before winter arrives.
Hiring a crop duster to fly on cover crop seed before harvest is another option, but timely seeding by airplane isn’t always possible. Plus, aerial applicators prefer to fly seed on large acreage farms and fields, not small areas.
Using a specially designed drone, Tom Leitgen can get the job done by flying cover crop seed into standing corn and soybeans preharvest. “Here in northeast Iowa, that’s the beginning of August to the first or second week of September,” he says.
In 2016, Leitgen designed and built the AeroSeeder, a drone system to help farmers broadcast cover crop seed. His dad gave him the idea after a crop duster had a late start applying cover crop seed in fields on the family farm near Garnavillo. Since then, Leitgen has been field-testing his drone and making improvements. He has applied for a patent and hopes to have the first three ready to sell soon, with more sold in the next year.
Advantages of drone seeding
In August and September, a ground-driven rig can’t seed cover crops into corn because the stalks are too tall. On soybeans, some farmers use a high-boy applicator, which risks soil compaction if fields are wet. Also, wheels must stay between the rows to prevent damage to the crop.
Some farmers are hiring crop dusters to broadcast cover crop seed into a standing row crop. A lot of the cereal rye is being applied by airplanes and helicopters in Iowa.
“Compared to an airplane, the drone is easily transported, is used by a wider customer base and can get into places in fields the larger aircraft can’t reach,” Leitgen says, such as terraces, grass waterways and wetlands. And a crop duster isn’t going to fly a plane very far from an airport just to seed 30 or 40 acres.
The AeroSeeder can carry up to a 30-pound load of seed and cover 100 acres in an eight-hour day. Since the seed weight per pound varies according to type of cover crop, the seed mix determines how many acres you can cover between having to stop and refill. “Our AeroSeeder drone can carry a 30-pound load of annual ryegrass seed and perform six flights per hour, which can cover about 18 acres,” Leitgen says. “However, the seeding rate can be adjusted based on a farmer’s needs.”
Savings from not having to hire a plane adds up over the years to help pay for a drone system. And crop dusters flying in the countryside are a safety risk, with powerlines, telephone poles, etc. “A drone system is safer and cheaper,” he adds.
How system works
The size of the seed tank on a drone limits the number of acres that can be covered per fill. This is also limited by battery life. When bringing a drone back down to refill the seed tank, you have to change batteries periodically, installing a fresh set. Drained batteries are recharged.
The fixed cost of this technology includes the drone and application equipment, equipment to mix cover crop seed, multiple battery backups, and a charger to recharge batteries.
PRECISION SEEDING: With the drone system, you can seed a cover crop more precisely, exactly where it is supposed to be.
Leitgen mixes cover crop seed before going to the field. He takes the supply of mixed seed to the field and refills the drone on every trip it makes over the field. Depending on seeding rate applied, the trips may last three to four minutes before the drone comes back to refill its seed tank and change batteries.
The drone ends up spending more time on the ground than in the air. He says eventually a system will be developed to automatically carry out ground activities when the drone returns to the ground station.
Also, if the pilot could swarm — one pilot running multiple drones — more drones could continuously operate. There would be three or four drones in the air covering acres, while one is refilling. The swarm method would allow more acres to be covered per hour, reducing the cost to the farmer. An Iowa startup company, Rantizo, was the first to gain permission from the Federal Aviation Administration for a pilot to fly multiple drones at once. (See the story on Page 44.)
Vision for the future
Leitgen has done a lot of fieldwork by testing his drone with farmers. He says he has a good idea of the practicality for seeding cover crops and what farmers need. “I’ve come up with a workable system that can seed acres more economically with a drone than with a ground-based system or an airplane,” he says.
About 70% of U.S. crop dusters are used in the Midwest; Iowa is known as “crop duster central.”
Leitgen says the development of drone systems to help farmers should stay close to home. “I feel very strongly the kind of technology we’re working on should be Iowa and U.S. technology,” he says. “These products could and should be built here in our state.”
Leitgen and his team are continuing to fine-tune the drone seeding system on his dad’s farm and nearby farms in Clayton County. “This could be a potential drone factory with our fields as the testing grounds,” he says.
Visit aeroseeder.com for more information.