The number of drones now on the market for agricultural uses almost equals the variety of breakfast cereals at the grocery store.
There may be many options for growers and agronomists, but there are basically three body types: multi–rotors, fixed wing and hybrids.
“It (a hybrid) is a vertical take off and launch fixed wing (drone),” said Matthew Johnson, president of M3 Aerial Productions in Manitoba, a drone service provider specializing in the agricultural industry.
“It’s a vertical take-off and launch fixed wing. It’s kind of like the American Osprey plane.”
However, most of the UAVs on the market are either fixed wing or multi-rotor. A few companies and drone websites claim that fixed wing drones are best suited for agriculture because they are faster, have a longer flight time and can carry more weight than multi-rotor drones.
For instance, several manufacturers claim that fixed wing drones can fly 45 to 60 minutes and cover 200 to 300 acres in a single flight, depending on conditions.
Johnson uses both fixed wing and multi-rotor drones when he works for farm clients. Is one body type better suited for agriculture?
“I’m going to lean towards saying no,” he said. “It really depends on what you need it for.”
In late April, Johnson used a multi-rotor drone for elevation mapping of 320 acres. It required five flights, and he said a fixed wing drone probably could have done the job in one.
He estimated that fixed wing drones can cover five to eight times more acres in a single flight.
“Depending on the overlap of the images that you are trying to gather,” he said, adding that elevation mapping on bare ground doesn’t require a huge amount of overlap.
“(But) as soon as you have plants in there, which are waving around in the breeze, you have to have a much higher overlap…. So that cuts down the amount of acres you can fly in one flight.”
Flying time and coverage are big pluses for fixed wing drones, but multi-rotors do have advantages. For one, they are simpler for novice operators.
“I would say the multi-rotors are the easiest to use,” Johnson said.
“They can hover. You could feasibly put your controller down and not worry about the drone. Versus the fixed wing, which is always moving and you always have to make sure that it’s responding.”
Felix Weber, president of Ag Business and Crop, which provides crop advice, technological support and drone services for farmers, isn’t convinced that multi-rotors are easier to use than fixed wings.
However, he agreed that both are useful in agriculture.
“The rotary wing is more of an inspection tool,” said Weber, who is based in Palmerston, Ont.
“If you know exactly where you’re going to fly and quickly inspect small areas … then the rotary wing can have its place, or if you map a very small area.”
Johnson and Weber said novice users typically start off with multi-rotor drones because they are less expensive. Plus, many people in the ag sector aren’t sure what to do with drones, so the cheaper options are more appealing.
“They’re getting the lower end, basic systems,” Johnson said.
“I suggest if you have no drone experience, use the multi-rotors and get some experience at capturing imagery.”
Putting the multi-rotor versus fixed wing debate to the side, Johnson said more attention should be given to the sensors attached to the drones.
A camera provides views of a field from a different perspective, but advanced technology such as near-infrared sensors can do much more.
“It’s easy to get fooled into thinking that just having the drone is enough to do everything that you’ve heard that drones can do.”
Weber made a similar comment.
“It’s not about flying the UAV, it’s about having data…. To get the right data, you’ve got to get the right tool.”