They stir the imagination and tickle the fancy of possibility, but for now, unmanned aerial vehicles (UAVs) in agriculture are still a work in progress.

They don’t zap insects, pull pigweeds or drive hungry deer from soybean fields – just yet. When a GPS signal shifts without warning, they might just land in a ditch full of water. Sometimes, they just fly off into the wild blue yonder.

But they can “see” fields from new perspectives, detect pest infestations more quickly, spot problems in equipment and get around the farm faster than you ever could in a pickup truck, leaving you more time to figure out, say, the new farm bill.

UAVs can also fly high enough to make pilots flying crop dusters and other aircraft a bit nervous. For now, the Federal Aviation Administration doesn’t quite know what to do about regulating them.

Nonetheless, the high-tech aspect of UAVs does stir the muse in farmers and researchers. And when farmers get excited about a technology that could save time, increase efficiency or help them better acquire the data they need to make smart crop management decisions, it usually finds its way onto the farm.

It doesn’t hurt when new technology brings a high-tech, glitzy look too, like the UAV demonstrated at the recent Northeast Research Station Pest Management and Crop Production Field Day, in St. Joseph, La. It looked like a big bionic spider and when operating, sounded like a swarm of angry bees.

Lots of questions

“We were getting a lot of questions this year from farmers about UAVs and drones, and what they can do for us,” said Randy Price, LSU AgCenter engineer, who built the UAV for study about six months ago.

Price’s UAV has proven rugged and airworthy, performing well even in 20-mile-per-hour to 25-mile-per-hour winds. Price says UAV technology to date, “has a half a foot in hobby use and half a foot in commercial use,” which means he’s always looking for ways to improve it for agriculture. For example, Price says, “In higher winds, cheaper plastic propellers may flex too much and can break. We’ve been using carbon fiber or heavy plastic props.”

With a computer program called Mission Planner, the user can define waypoints for the UAV. While UAVs and drones can easily fly these pre-programmed routes, Price suggests users learn to remotely control their UAVs – just in case. “The WAAS (Wide Area Augmentation System) GPS works pretty good, but sometimes it’s five feet to six feet off. Once, our UAV took off on a road near a farm field, and when it came back to land, it landed in a ditch. If the ditch is full of water, you don’t want to land there.”

Price says some models have been known to fly off and get lost, likely due to the UAV not knowing its “home” position. “If they get in trouble, they are supposed to come back and land automatically. This one has a geo-fence in it. If it goes over 500 feet away, it hits the geo fence, and it will come back and land.”

FFA rules and regs

The FAA is in the process of developing rules and regulations for the use of UAVs, Price says. “They are a little worried because UAVs are going to be flying in civilian airspace. This UAV can fly at 10,000 feet if I wanted it to. For now, the FAA is requiring they fly below 450 feet and always be within your line of sight. The devices can’t be flown within three miles of an airport.”

A new report on UAVs from the National Research Council stresses caution for the budding industry. It stated, “While civil aviation is on the threshold of potentially revolutionary changes with the emergence of increasingly autonomous unmanned aircraft, these new systems pose serious questions about how they will be safely and efficiently integrated into the existing civil aviation structure.”

While the chances of a collision are low, Price understands the concern. “We have a lot of agricultural aircraft around. Crop dusters are supposed to fly at 500 feet when they ferry between fields. But most of the pilots fly at treetop level. So we have to be careful.”

Costs vary widely

Prices for UAVs vary widely. Off the shelf, UAVs like the one Price demonstrated run in the $3,000 to $5,000 range. To self-assemble Price’s UAV would cost about $1,500 plus camera or video. Free and reliable firmware and software is available for most models, Price says.

Price’s UAV is battery-powered and has a flight time of only 10 minutes to 20 minutes. “That’s okay for plot work, but that’s a bit short if you are flying producer-size fields,” Price said.

 “Bigger UAVs can lift more and carry longer-lasting batteries, but the price jumps up dramatically. There are UAVs twice this size that cost $15,000 to $20,000. With an remote-controlled airplane, you can probably cover 640 acres in one flight,” Price said.

RTK-equipped drones for professional mapping and surveying can cost in the $50,000 to $60,000 range, according to Price. “But in 15 minutes, it could do the work of one person working 8 hours.”

UAVs are starting to catch on in crop consulting, too, helping consultants cover larger areas more quickly and reliably, pinpoint problems and capture video or photographic images.

A small camera mounted on Price’s UAV costs about $200. A company, Maxmax.com, can install a conversion lens on the camera that produces images indicating various levels of plant vigor. Another company at diydrones.com, provides manuals to assemble a UAV.