San Patricio del Chañar, Argentina. This tiny town’s growing economy is fueled by agriculture, hydroelectric power, and drilling for oil and gas.

Satellites vs. Drones: The Technology in Your Vegetables

Clay Mitchell was always going to be a farmer. He knew it as a kid, growing up on a farm in Iowa that his family had owned for five generations, and he knew it even when he left Iowa after high school to study biomedical engineering at Harvard. There was no question he’d find a way to get back to farming. “It’s just defining of who I am,” he says. “It’s just what I love most.”

Before he graduated from college, Mitchell took out a loan and bought some land of his own in northeast Iowa, a plot that eventually grew to 2,500 acres of corn and soybeans. He became a new breed of high-tech, data-driven farmer. From the beginning Mitchell was a big believer in precision agriculture, the idea that farmers can use monitors on the ground and eyes in the sky to identify problems and opportunities. In 2011, after years of working on his own farm, he co-founded Fall Line Capital, a private equity fund based in Silicon Valley that relies on methods of precision agriculture, including high-resolution satellite imagery like the kind provided by Planet Labs, to buy and improve farmland across the country; Fall Line raised $125 million by 2013. “It’s critical,” Mitchell says of satellite imagery. “It’s part of everything we do.”

Satellites or Drones?

Drones, of course, can also take aerial photos of crops and fields, and because they fly lower than satellites, they can image things at the centimeter level. By now lots of farmers have either seen demonstrations of drones or have experimented with the machines themselves. But while drones have their uses, they’re impractical for many tasks, Mitchell says.

The main reason is scale. The Federal Aviation Administration requires drones to top out at 500 feet, which means that often times a drone can only photograph a fraction of a field. So the drone has to fly over the field multiple times — and then move to the next field, and the next. If clouds move past the sun, the light changes, and it gets harder to stitch the images together later, a time-consuming process known as “mosaicing,” which also requires the farmer to run out into the fields before the drone flight and lay down grid markings to give the people making the mosaics a set of geographical reference points.

Basically, you need a lot of drone-hours and people-hours to do the job well for any farm of significant size, and if you add more land to your farm, you need more drone-hours and people-hours still. This is to say nothing of the hassles of actually piloting the drone — an FAA Section 333 exemption is mandatory for agricultural use — and the risk of a crash. “It’s difficult to scale effectively with drones,” Mitchell says.

Satellites scale. The image from a satellite has a big enough footprint to cover a large area like a farm, and satellite imagery is also cheaper than drone imagery. FarmLogs, a Michigan company founded by farmers, uses Planet Labs satellites to image the fields of its 100,000 users as many as five times during a growing season, providing measurements of vegetation, fertilization and fertilization needs, the nitrogen content of soil, and crop-health alerts by email.

“That Just Stuns ‘Em”

FarmLogs chief agronomist Tracy Blackmer regularly attends crop conferences and gives talks to farmers, showing examples of 5-meter-resolution images taken by Planet’s satellites. He finds that until he shows the pictures, farmers often aren’t aware of how good the satellite imagery has gotten; the last pictures they saw were from 10 years ago, when satellites could only take pictures of fields occasionally, with poor resolution. “Everyone thinks it’s too coarse to see anything,” Blackmer says.

Then he puts up the pictures. Here’s one that shows a field marred by a fixable equipment problem. Here’s one where you can see the wheel tracks of a malfunctioning combine. “They’ve all been told you can’t do that” with satellite images. Then Blackmer tells them, “This data’s being saved. That’s important, because land’s changing all the time. Maybe you’re thinking about buying this other farm. We can go back six years and show you the problem areas.” With satellites as opposed to drones, they’re getting the sweep of history instead of just a snapshot, for a cost as little as 20 cents per acre per year. And the satellite imagery is only going to get better and more frequent. “That just stuns ’em.”

The Long View

As helpful as the imagery can be to individual farmers, there are also some bigger possibilities. Clay Mitchell is using satellite data to select land to buy for his equity fund — to “avoid lemons and buy undervalued farms,” and then to deeply understand the limitations of purchased land and overcome them. Are fields getting too much water? Does the soil lack iron? Is it salty? He can go back into the history and see how the land performed during period of heavy rain. Did it flood? How much? Did the water drain away quickly or did it take a week? With a quick glance at the imagery, he and his team can tell both the severity of the problem and how much land is affected.

In the short term, approaches like these should increase yields across a wide variety of farms, leading to lower prices for consumers. But Mitchell is also thinking about how farmers will feed people 100 years from now, and 500 years. One percent of the world’s farmland is lost to erosion and bad farming practices every year, yet the need for agricultural products keeps growing. Precision agriculture, enabled by satellite imagery, can return degraded farmland to productive use. “Well-managed farmland,” he says, “is like an oil well that never goes dry.”