A six-rotor hexacopter drone is being used by Rantizo as it develops its autonomous crop spraying system. PHOTO RANTIZO
By Dave DeWitte
A fleet of 10 drones hovers over fields of Iowa soybeans, intermittently releasing a fine mist of herbicide just a few feet above the growing plants.
The drones are a mesmerizing sight as they crisscross the fields in a seemingly orchestrated ballet, covering large swaths of land without releasing any mist at all, and then dispersing a barely visible trail. Once in a while, a drone diverts back to base, where it lands to refuel.
This scene is closer to reality than you might think. Rantizo, a Corridor-based startup, is developing an autonomous drone-based sprayer system for precision agriculture that it plans to bring to market in the fall of 2019.
Michael Ott of Iowa City founded Rantizo in 2017 after 16 years of leadership roles in venture capital, bioprocessing and startups focusing on agricultural advancements in algae and plant growth. He believes his company’s system can reduce the cost and improve the effectiveness of ag chemical application by applying just the right amount at just the right time to the areas of the field that need it.
Reducing chemical usage will also combat a growing concern for farmers, Mr. Ott said.
“All of the work is being done by the chemical in agriculture right now,” Mr. Ott said. “What happens is some resistance develops to an herbicide, so more chemical is applied, which increases resistance, so more chemical is applied. You get caught in this feedback loop.”
One of the key features of the Rantizo system will be electrostatic sprayers that give each molecule of the chemical applied a negative charge. The negative charge causes the chemical to cling to the surface of the plants – even the underside of leaves – to maximize its effectiveness.
“This results in a very even coating because it pushes away from itself,” Mr. Ott explained. “It wraps around the top and bottom of the leaf.”
The electrostatic sprayers also compensate for one limitation of small drones, which is their inability to carry a lot of weight. While conventional sprayer systems heavily dilute agrichemicals, Rantizo’s system will deliver it in undiluted form, and can distribute amounts as small as one ounce over an entire acre.
The drone Rantizo envisions using for its system has four rotors connected by a frame in a diamond configuration. Its maximum payload is about 16 pounds, but each drone will be able to cover a surprisingly large area per flight, and a number of drones will be operating simultaneously.
“We may cover eight acres [with one drone flight], but we’re only spraying two because we’re only hitting the areas that need it,” Mr. Ott said.
Farmers once identified weed infestations and insect damage by walking their fields or driving to accessible areas, but in recent years, they’ve been able to save time by subscribing to satellite services that allow them to inspect their crops from their laptop or tablet.
“A lot of farmers are doing it every three to seven days,” Mr. Ott said. “It’s always a dynamic situation.”
With the benefit of satellite images, Mr. Ott said farmers now have a new challenge. At a time when weed or pest infestations are worse, there’s often a serious bottleneck in high-demand services such as custom chemical applicators and crop dusters who spray with airplanes or helicopters. They’re also often prevented from treating problem areas with their own equipment because of wet soil, which can lead to soil compaction.
Drone spraying, by contrast is “much more agile,” Mr. Ott said. The farmer or custom applicator can apply the herbicide just when the weeds are emerging, reducing the volume of herbicide needed and eliminating soil compaction concerns.
On the horizon
The drone industry has already recognized the potential market for sprayer drones, with many options now available, and at least one company advertising a semi-autonomous fleet that would enable one worker to manage up to 10 drones at once.
“Agriculture is considered a prime area of potential growth in the drone industry because of the technology’s ability to help survey crops and gather real-time information on farmland,” the Wall Street Journal reported in November 2015, highlighting China-based drone maker DJI’s foray into “agra drones,” which sold for about $15,000 at the time.
One of the autonomous features Rantizo is working toward is a system that allows drones to autonomously land and replace spent chemical cartridges and batteries with fresh ones. Besides saving time and reducing labor inputs, Mr. Ott said the system will reduce the risk of exposure to ag chemicals.
Most of the technology the company plans to use in its drone-based system is already commercially available, Mr. Ott noted, although considerable work remains to be done to integrate it into a system that performs the specific tasks Rantizo wants to provide its customers.
From its current team of five, Rantizo plans to add two engineering positions in the coming months to advance development of the platform. Some of that work will also be outsourced.
Initially, Mr. Ott said, Rantizo’s customers will be custom applicators.
“That gives us access to the most acres with the fewest number of sales,” Mr. Ott said, “and then our next market would be large farmers, and then down to the other farmers.”
The custom applicators are also experienced ag chemical users, Mr. Ott said, with the training and certification needed to meet applicable regulations. That doesn’t mean they’ll have all the certifications needed for the Rantizo platform, however. Mr. Ott said it’s expected that users will have to secure a drone operator certification from the Federal Aviation Administration.
Safety concerns remain about operating drones for commercial purposes in civilian areas, but Mr. Ott believes agricultural uses are a good place to begin integrating them into the economy because the operations will take place in areas away from intense human activity.
The idea for Rantizo came to Mr. Ott after he worked as part of a precision ag startup that developed a seed injection system that coated the seeds with nitrogen fertilizer to spur early growth. He teamed with Matthew Beck with, a former McKinsey & Co. consultant who grew up on a Nebraska farm. Mr. Beck with serves as chief operating officer of the company, which is performing tests with a prototype system on a farm near Durant.
From its current single-drone setup, Mr. Ott and Mr. Beckwith hope to scale the system’s capabilities incrementally to 20 drones. The concept received some validation last May, winning the agricultural startup pitch competition at AgLaunch in Memphis, Tennessee.
The next year will test the startup’s will.
“It’s new challenges every day and we’re solving problems that, to my knowledge, nobody has ever addressed,” Mr. Ott said. “But I like these new challenges, because I think we’re doing something truly worthwhile.