UA Ag Center using drones to survey farmers’ fields

Posted: Sunday, July 12, 2015 1:15 am | Updated: 8:24 am, Mon Jul 13, 2015.

By Kevin G. Andrade, Yuma Sun staff writer

For two and a half years, the University of Arizona Agricultural Center in Yuma has been hovering on the cutting edge of technology, exploring the uses for unmanned aerial vehicles (UAV) in farmers’ fields.

“We started with just $1,000,” Dr. Kurt Nolte, director of the Agricultural Center and the Ag UAV program. “Now we have acquired the funding for more sophisticated systems as you see here.”

“These are mostly to help assess crop health,” said Nolte. “We can look at plant growth in the field from above.

“Getting a chance to see the crop from above is something we can’t do but these little things can,” he continued, pointing to a small, white UAV — or drone — next to a large remote control.

The UAV was an Inspire I quadrocopter — so named for the four-rotor system it uses to fly. With a cost of about $2,500, it certainly is not something to buy for a child’s Christmas toy, although it may look like one. But for the farmer, it is a bounty.

“This machine is essentially a Cadillac of UAVs,” said Nolte. “We use it for crop assessment out in the field.”

Soon after kicking up a small amount of dust, the small white UAV jumps up into the sky and quickly rises above the heads gathered on a field near the Ag Center.

“When she’s up in the sky, she can gather images of the crops from the camera underneath,” said Nolte. “Its camera transmits a wireless feed to the iPad.”

There are also fixed-wing options for drones. There are some distinct advantages to using a rotor-based craft in order to take photos.

“The thing about fixed-wing aircraft is the plane has to keep on moving,” said Nolte as the UAV hovered over the field. “These can hover but the disadvantage is that if you really want to get a defined image of a particular plot of ground, it saps the battery life to keep it hovering in position, it brings it down to 25 minutes.”

Still, the advantages appear to be greater than the downfalls.

“Say that we want to monitor the nutrient deficiency and diseases in citrus trees,” said Nolte. “When you’re walking through a grove, you can’t see probably what is going on up top without a UAV.

“Or if you want to look at water distribution in a field,” he continued, “you can examine that from above.”

Some cameras can even pick up on the amount of light reflected by a plant, deciphering which crops are healthy and which may be suffering from disease.

Flying UAVs to assess their fields may be a better alternative for farmers, especially with the costs associated with hiring a pilot to do multiple passes over a field during a survey. Nolte also noted that, because the UAVs are battery powered, there are no emissions associated with them.

After they finished flying the Inspire I, Nolte and Rosa Bevington, a media specialist with the University of Arizona Cooperative Extension, broke out the other apparatus they brought along with them — the Heavy Lift Octocopter.

The eight-rotored, 12-pound, Heavy Lift Octocopter looks like a large, skinny, black spider with legs reminiscent of a spider crab.

This particular device is capable of lifting up to 15 pounds and requires two people to operate: one piloting the vehicle, with a camera pointed straight ahead, and another with the camera pointed at the ground, to make observations on the field.

Prices on these systems can vary, with the Heavy Lift costing $10,000, without the cameras, and the Inspire I costing $2,500. However, a beginning UAV system can be purchased for as little as $600.

Seeing that the program is still in its infancy, Nolte said that they are not getting too adventurous so as to not run afoul of the Federal Aviation Administration or their funders.

“We are sticking to the basics,” he said. “We don’t want to do anything that will compromise the program.

“It is in its infancy,” he continued. “And we have been at it probably the longest out of anybody… Right now there is more investment in new camera systems and sensors… The tech is going to advance.”

Of course, one of the major points of scientific experimentation is to ensure that results are repeatable.

“There’s an integrated autopilot and that is given a flight-pattern to fly,” said Nolte. “Every picture of a geographic reference area is stitched together into a collage after.

“We’re able to program it so it has a definite north, east, south and west orientation and altitude,” said Nolte. “We want to make these flights repeatable so as to confirm observations.”

There has been interest in the program, Nolte having given workshops on UAV use in agriculture in many places, such as recent conferences in South Dakota and Louisiana. But the interest is just starting to show up locally.

“We have programs in place to assist farmers in using these,” said Nolte. “We’ll definitely be on the cutting edge of technology.

“There is interest locally, it’s just that the technology is so new, so it’s not as much as it could be,” he continued.

With the rise of drones in different sectors of society, some people are concerned about privacy. Nolte says that while that may happen in the future, right now it should not be too much of a concern.

“There’s always privacy issues no matter where you go,” he said. “We definitely do not fly over a grower’s field unless we are invited to do so.

“As the industry gets more advanced, I’m sure there will be more privacy concerns,” he continued. “But we don’t intend on doing anything higher than a palm tree.”

Kevin G. Andrade can be contacted at 539-6853 or

Zipping alongPhoto by Randy Hoeft/Yuma Sun

Zipping along


The DJI Inspire 1 zips along during a demonstration flight at the University of Arizona Yuma Agriculture Center.