Associate Farm Reporter Carli Davenport spoke with OSU Extension Weed Specialist Liberty Galvin, who discussed how drones are creating new opportunities in modern agriculture, both for livestock and crop production. She explained that “drones are a technological opportunity for us to expand our agricultural operations”, noting that producers in Oklahoma are using them to “scout fence lines and monitor their cattle.” As a weed scientist, Galvin emphasized her focus on pesticide use and said drones provide “a great opportunity to expand our spraying capabilities, because drones don’t touch the soil.” This allows producers to apply products “when the soil is wet or over tall crops, giving them a little bit more flexibility.”
A point of concern in her research is droplet size and drift during aerial spraying. Galvin explained that “the EPA and the U.S. government have been really cracking down on drift recently,” and that drift potential depends largely on droplet size. She warned that “any droplet size that is less than 150 microns has high potential for drift,” whether applied from a ground rig or a drone. To minimize risk, she said, “I really encourage people to use more of a medium or even a coarse size droplet,” since “fine droplets just become mist, and they carry in the wind. And we live in Oklahoma, so we’ve always got a little bit of wind.”
Galvin also clarified the difference between hobby drones and spray drones used in agriculture. “A hobby drone is less than half a pound,” she said, meaning it isn’t subject to the same FAA regulations. But, she added, “any drone that is making an agricultural operation is automatically going to be considered an aircraft,” and therefore requires “a lot more licensure than just an individual with their pesticide applicator’s license.”
Looking ahead, Galvin said she sees tremendous potential for drone technology in both crop and pasture systems. “You can spread seed with a drone, put down fertilizer, and spray your herbicides,” she said, emphasizing that drones can “reduce soil compaction by not touching the soil.” She noted their usefulness on uneven terrain, explaining that “the terrain is never level, drones don’t have to touch the ground, and it doesn’t matter if there’s a big hole in the field or a big divot.” Modern software, she added, helps drones “stay at a consistent height above the ground” and navigate obstacles like “tall trees or big canyons.”
While optimistic, Galvin cautioned that “we’re really going to get ourselves in trouble by not paying attention to drift — people flying too fast, flying too high, having really fine droplet sizes that are drifting onto their neighbors.” Despite these challenges, she believes “drones have a really big role in the future of agriculture,” particularly in places like Oklahoma, where soil conservation is a top priority.
