WEST FARGO, N.D. – After several days of heavy rain, part of the field demonstrations at Big Iron had to be cancelled. The subject of precision spraying was going to focus on the ability of ground sprayers to engage in precise spraying, and also the opportunities unmanned aerial systems (UAS) provide in this area.
The ground sprayer portion had to be cancelled because of the muddy field conditions and the deep ruts the sprayers left in the field. But, on a positive note, it did allow for more time in the field demo each of the three days to focus on using drones for agricultural spraying.
The use of drones for agricultural spraying is opening up many possibilities for traditional aerial applicators, according to John Nowatzki, coordinator of the field demonstration program and also Extension ag machine specialist at NDSU.
“I had an aerial applicator tell me that he gets requests that are too close to a farm yard or too close to a town and he has to turn them down,” Nowatzki said. “He said he turned down $100,000 worth of business in one year, but if he had a drone in the back of his pickup, he could spray those areas. So the use of a drone would actually enhance his business.”
The versatility and precision of a drone for spraying operations was demonstrated in two ways. First, individual marker flags were placed in the field representing individual weeds that needed to be controlled and a patch of weeds was represented by a white tarp spread out on the ground.
Those same imaginary weeds would have been used to demonstrate the ability of ground sprayers to only reach certain sections of a field using such things as a boom or individual nozzle control, but field conditions made that impossible.
The drone used in this spraying demonstration is owned by the NDSU Agricultural and Biosystems Engineering Department (ABEN). It has a flying time of about 20 minutes on a single battery charge and can handle winds up to 20 miles-per-hour, according to Nowatzki. Once launched, the drone would be able to spray three or four acres before the sprayer tank would need to be refilled.
However, a few days prior to the Sept. 10-12 Big Iron Farm Show, a different drone was used to spot some imaginary weed plants and areas and map them out for the spray drone to seek out during the field demo. This early mapping represented how drones can be programed to take images in a field and identify certain weeds that need to be controlled. They can then mark the location of those weeds using a shapefile so every point on the shapefile is a weed and then that shapefile is loaded into the drone doing the spraying.
“What we are talking about is highly geo-referenced accurate equipment and the drone we are using for spraying today is not one of those machines,” said Sheldon Tuscherer, research specialist in the ABEN program. “It will be within about five feet or so of these points. If you really want to do this accurately, in the GIS world we will talk about RTK data and that is what we would need with this machine to be really accurate – that wasn’t our goal when we got this machine.”
Once it takes off, the drone flew autonomously from the launch site to the weed positions in the field at an altitude of around 30 meters. It dropped to a height of around two meters for the spraying operation. Once the spraying operation was completed, the drone automatically returned to the site it was launched from.
In closing the session, Nowatzki said anyone thinking of flying a drone in the U.S. must have a license, and after studying the material, there is a test that takes about three hours to complete. The license is good for three years, and currently, there are three locations where the test is given in North Dakota – Fargo, Grand Forks and Minot.