Flying high

WISCONSIN DELLS, Wis. — Developing new technologies to improve field health is an ever-evolving field. One of the latest strategies is using unmanned aerial vehicles to provide a bird’s eye view.

Using UAV technology, crop consultants and farmers now have a new tool to jump on potential issues in the field and improve crop health. Earlier identification of problem areas leads to earlier treatments and improves the overall health of the field.

Brian Luck, an associate professor in biological systems engineering at the University of Wisconsin–Madison, presented his findings on using UAVs to monitor field health and regrowth at the hay symposium presented by the Midwest Forage Association in February.

Luck discussed how he and his team utilized UAVs to monitor crops, specifically corn and soybeans. He said their conclusions could be useful for alfalfa health and persistence as well.

“Drones provide an overhead visual of your fields and can help you cover more acres, compared to walking the fields,” Luck said. “Beginning to use a drone is a big investment. It’s like buying a tractor, but it can help you cover more irregularly shaped fields, or fields that are harder to get to.”

Luck showed pictures of a cornfield during the early stages of growth. In the drone photo, the audience could surmise where there were potential issues during planting. People could see less plant density in the middle of the field, potential effects from wheel traffic and even monitor the fertilizer application.

“In 10 minutes of flying the drone, we can get a better visual of where the potential problems in our field are,” Luck said. “I’ve recommended using drones to crop consultants who have come back to me and said that using a drone saves them hours per field because it can provide a more specific area to look for potential issues.”

The UAV is a way to present a more consistent approach than walking a field to determine where the field might need extra help.

“When we look at our field from our drone, we can see where we might have had some planter issues,” Luck said. “You can see how the nitrogen application didn’t reach the edge of the field. There are tillage lines.”

Using UAVs, Luck and his team attempted to determine alfalfa’s persistence between cuttings, dependent on wheel traffic. Luck and his team monitored all the machines that went in and out of the field for a separate study about how tire treads can affect persistence. The team took overhead photos immediately after harvest and 10 days after harvest and saw differences.

“We saw a direct correlation between our GPS-tracked truck that went directly across the field,” Luck said. “We only had one vehicle do that, and there’s a path cutting across the field with smaller alfalfa plants that were clearly affected by the tire traffic.”

The clear visual on the regrowth of that alfalfa helped prove tire treads effect alfalfa persistence.

Luck also discussed the ability to utilize UAVs to spray fields with pesticides, fungicides or herbicides. A person applying products and operating a drone weighing more than 55 pounds needs to be a licensed drone pilot with a Federal Aviation Administration Part 107 license.

Fully loaded UAVs used for spraying can weigh 130-140 pounds and are advertised as having the ability to spray 53 acres per hour. Luck and his team said a more accurate estimation is 40 acres per hour, depending on the time it takes to reload the UAV.

“The sprayer we worked with was an atomizer,” Luck said. “It had a gap with a spinning plate that spread out what we were spraying. It wasn’t a pressure nozzle like we’re used to seeing with sprayers. It covered about a 30-foot swath. We found it worked better with low-volume applications like fungicides or insecticides.”

To test the UAV’s effectiveness, Luck and his team ran a test plot with soybeans. They determined the portion of the field with no fungicide application saw a reduced yield, while the portions of the field sprayed with a fungicide, both traditionally and with the UAV, saw a similar yield increase when compared to the no-spray group.

The drones combated prevailing winds and provided an even spray in the field because the UAV props itself as needed to counter wind.

In summary, the UAVs provide new technology to help better maintain the overall health of the fields. From identifying specific problem areas of the field to helping limit the amount of damage that could be done by pests or weeds, UAV technology can be used by the agriculture industry to continue to provide the best feed possible.