by Courtney Llewellyn

Kurt Babcock, aerial ag tech and Rantizo Application Services contractor, based in Iowa City, Iowa, asked those in attendance at the Great Lakes Expo “Is drone spraying the future of agriculture?” before answering his own query.

“It’s a trick question,” he replied. “It is the present of agriculture.” He noted the company he works with, Rantizo, conducted over 46,000 flights in 2021. He also spoke more on drone-based chemical application in fruit production systems.

Where does drone spraying fit with current practices? Babcock said it’s complementary to existing technology – it is not a replacement for ground rigs or full-size aerial aircraft. “It’s another application tool in your IPM toolbox,” he said. And that tool can assist when repeated applications are necessary, or when a grower has labor problem issues.

“The potentials of drone spraying are limitless with the ideas people come up with,” he said. He listed herbicide/fungicide/insecticide spraying, seeding for cover crops, precision nutrition, event rescue sprays, pollination, research trials, herbicide burn downs, treatment in awkward areas and more as current usages. “The idea is if it’s not done now, let’s try.”

With the many applications come many advantages, including control of application, spot application and variable rate application; no soil compaction, no crop damage and no chemical overuse; less pesticide exposure; easier application in difficult terrain; less water usage and less runoff; and reduced emissions from ground-based equipment. Babcock said drones are especially useful for the tops of hops and hemp, where a lot of other sprayers have issues providing good coverage.

“There are challenges too,” Babcock noted. Current battery size only allows flights of certain lengths, as do current tank sizes. Advancement costs can be steep – he said Rantizo runs $35,000 to start (including equipment) and contractors’ fees are $150/hour. The technology can become outdated quickly. Regulations can create issues, including FAA certifications. Waivers may be needed for specific flights, and state licensing varies from state to state (Michigan got approval for this July 1, 2020; it’s been in California for a while). There’s also the cost of insurance for drone usage.

The pros and cons are things growers need to seriously consider before diving into drone spraying. If they decide they want to explore this, there are a series of steps to be taken for those drone flights. First, a detailed map helps to find the best course for the drone to take, which leads to identifying issues (sometimes using normalized the difference vegetation index, or NDVI), which then leads to diagnosis (with the grower physically looking at their crops and deciding what needs to be done). This will lead to spray application, which should then lead to verification (making sure the application is working). “It’s all a team effort,” Babcock said.

And the team effort is ongoing. Babcock said research is still needed for both current and new technology – specifically, pump technology (pressure vs. centrifugal), swath coverage, spray nozzles and lower rate applications. “This is where we need help from growers,” he added.

Babcock summarized the current state of the matter thusly: “Even though in its infancy, spray drones are currently used to handle today’s agriculture. Technology is going to continue to evolve, improving the effectiveness and efficiency of the spray drones.”