Crop Dusting In Wisconsin

DJI T-30 Drone Sprays Crops

We visited Beth’s family in Wisconsin in July 2023. One of her six brothers is still running the family dairy farm. He has several hundred acres of crops growing, and they need to be sprayed with pesticides and fungicides.

In the past, this involved small acrobatic crop-duster airplanes that swooped in and out of the fields just feet above the crops. Now, there are special drones with 7-gallon tanks and sprayers that can cover 100 acres in just over an hour.

The drones used today are DJI model T-30 agri spray models. Before starting, the operator outlines the fields with a map on the computer. Then, the computer programs the flight paths for each drone and they steer themselves up and down the rows of crops even a half mile away as they send live video back to the computer. They even turn around at the end of each row and line themselves up on the next row to minimize overlapping or missed areas. It’s especially impressive that there are two drones running at the same time. Amazing!

Each battery lasts less than 10 minutes, so they have to come back to the launch pad for a change of battery and spray refill. Then, they’re off for more spraying while the first battery gets a fast recharge. By rotating 3 or 4 batteries, it’s a continuous operation.

Getting set up to start. Both drones are anchored to this launch pad on the trailer. Two generators power the fast chargers to ensure a steady supply of freshly charged batteries for the drones. Different sprays are kept in two containers that have a hose and pump to fill the drones’ spray tanks. Very efficient!
Greg is getting everything organized – generators to quick-charge batteries, spray mixtures, computer GPS programming, etc.
One of the DJI Model T30 agricultural spraying drones. Each of these costs around $20,000. It has 6 electric motors that can lift the 7-gallon payload and fly around 7-8 minutes on a single charge. By rotating 3 or 4 batteries and quick-charging, the drone can be kept operating almost continuously with short pit stops to refill the spray mixture. Pretty amazing!
Here, you can see some of the spray nozzles under each motor.
Greg is filling the 7-gallon tank with spray mixture before launching the drone over the corn field.
Last minute preparations to launch.
With the flight plan all mapped out on the laptop, the first drone is sent off to start spraying. Using a digital map, the program automatically steers the drones up and down the rows of crops and returns it to the launch pad when the batteries and spray mixture need to be replaced.
Heading out from the launch pad.
The drones fly about 20-30 feet above the crops and cover a path around 50 feet wide.
Spraying the corn field.
You can see the spray under the drone. The propellers help direct the spray downward.
Coming in for a fresh battery and spray refill.
By flying low and with the propellers directing the spray downward, the drones can operate near homes with almost no overspray – which was always a concern with crop-duster airplanes.
Almost done. It only took about 20-30 minutes to spray over 30 acres of corn fields.
Just a few more passes and we’re done.
All done. Time to bring in both drones and get them anchored down to the launch pad. Greg makes it look easy.
And here comes the second drone. Job completed.