Update, July 20, 5:40 p.m., EST: This story has been updated to include additional information about Farmers Business Network’s practices and appeal to investors. 

Update, July 25, 4:55 p.m., EST: This story now includes comment from Syngenta on its business practices. 

In March, I visited grain farmer David Seba in Cleveland, Missouri. Winds were gusting at 45 miles an hour, so he couldn’t spray the crops in his fields. We talked in his office, where a tin roof rattled and shook.

That day, John Deere stock was trading at $158 a share, and had been trading at an all-time high just a few weeks earlier. Seba said he was convinced that the world’s largest manufacturer of agriculture and industrial machines had become so valuable not because of its machines, per se, but because of the data those machines were collecting.

Deere equips tractors with sensors that pull all manner of farming data—from the presence of nutrients in the soil, to the locations of seeds planted, and the volume of crops harvested—for the benefit of farmers who own its equipment. Since the first crop monitor appeared in a Deere combine in 1995, precision agriculture (as the data-heavy practice of computerized farming is known) has been hailed as key to improving the efficiency, and ultimately the yields, of commodity and large-scale farmers. Automated tractors equipped with GPS sensors and remote controls now farm up to 70 percent of cropland in North America.

Seba sees it differently. It’s one thing for Deere to use his data to make a better tractor. But, he said, Deere knows when he’s planting, and he’s convinced the company sells that data to weather companies and commodities traders. Deere denies that it sells aggregated farm data to traders. Nevertheless, it’s the billions of acres of data the company collects that allows it to enter into lucrative business partnerships with complementary companies, such as Dow DuPont, which depends on soil information to make nutrient and seed planting “prescriptions.”

“All this incredible technology that everybody’s come up with, that everybody talks about—are we making any more money? We’re making less,” Seba said. “So what it’s done is make companies hugely rich, which is fine. I’ve got no problems, but why would you not—throw me a bone, you know? Why can’t a farmer participate in giving his data, and getting paid for it?”

For the last decade or so, machine manufacturers, seed giants, and Silicon Valley-backed software developers have depended on data to grow their businesses. Deere has declared precision services key to becoming a $50-billion company. Monsanto bought a weather analytics service that crunches data for farmers. The seed giant, which will fold into Bayer in a recently announced acquisition, has spoken of a future where “the information itself becomes the business.” Dow DuPont, a rival, offers its own farming services through a data platform that the company expects to bring in a half-billion dollars a year.

The trouble is, we don’t really know what these companies are doing with all the data the tools are hoovering up.

“They are basically in a race to gather as many total acres of data, ingest it into the system, and I don’t know if anybody knows exactly what they’re going to do with the data,” says Steve Cubbage, an agronomist with Farmobile, a data startup based outside Kansas City, Kansas. “They know if they’ve got it, they’re in control. It’s a giant land grab.”

Until now, farmers have basically given away data to the companies that manufacture their machines. Deere, of course, collects data that way. Other companies, however, dangle a carrot in return for the information.

Farmers who buy $45,000 worth of chemicals and fertilizer from Syngenta, for example, can use the seed company’s AgriEdge software for free. Those who participate in a related farm management system called Sustainable Solutions use that software to submit inventories, including from other companies in use on their farms.

“If I’m Syngenta, wouldn’t it be nice to know what they paid for a Monsanto seed?” said Patrick Christie, founder of Conservis, another agriculture software company, when I met him at AgTech Nexus, a recent investor conference in Boston. Aaron Deardoff, Syngenta’s head of digital agriculture systems, tells me the company does not collect the names of rival input producers.

Farmobile, on the other hand, wants to empower farmers to see their data not as the property of another company, but as another crop—something they grow and sell for income. This week, the company launched a data store, where potential buyers search for data-infused farm maps called electronic field records.

Here’s how it works: Farmers collect data through a passive uplink connection, or PUC (pronounced “puck”), which they purchase for $1,250. The small, orange box plugs into most tractors, and sits under the driver’s seat, in the cab. The PUC collects machine and agronomic data as it comes up from sensors in the field. Right now, says Jason Tatge, the company’s founder, there are around 2,000 of these devices in the field, and a closetful of them at the office in Leawood, Kansas.

Farmers can share that data as field maps with their agronomists, or consultants, or insurance agents—shared information that specifically benefits the individual farmer and their operation. Or, they can sell it to interested buyers. After planting and harvesting, farmers certify the data and make it available for licensing—a recurring revenue source, with the option to sell multiple times—in Farmobile’s store. Farmobile is offering farmers quarterly payments of around a dollar an acre, per field record, according to Tatge. If a farmer has been keeping track of planting, spreading, spraying, and harvest, those payments could end up closer to $5 an acre.

In theory, the store represents big opportunities for farmers who need a new stream of revenue, but also for buyers who crave specific, county-by-county farm data. But some industry insiders don’t believe Farmobile’s model will be viable until farmers first see how the technology—a platform-agnostic PUC that works with most machines, distilling the data into comprehensive, easy-to-access maps—helps them improve their normal farm operations.

Farmers Business Network, a Silicon Valley-based software company, often described by tech press as a social network for farmers, offers a $600-a-year analytics service that ranks farms based on their seed and crop data. Charles Baron, the company’s co-founder, says that investors, including Singapore’s sovereign wealth fund, are interested in the company because it uses data to match buyers to the growers of particular products. Farmers Edge, a software company that unsuccessfully sued Farmobile, alleging Tatge stole its technology, provides remote agronomics for farmers. The Winnipeg, Canada-based company has a hundred-million dollar valuation, according to Crunchbase.

Farmobile isn’t just trying to suck up data, but also to create a semi-public marketplace for it. Observers are skeptical that there are buyers for that data because avenues to collect it are already well-established.

“If the farmer is able to curate, organize, parse and analyze that data so that they can reduce the cost of spraying or use less fertilizer, that’s immensely valuable to them. So why would they want to sell that data to anybody else?” Zuckerberg asks. “They might as well realize the value in the form of less inputs purchased.”

The big companies are opaque about the data they’re collecting, perhaps in part because they don’t know what they’ll do with it yet, beyond analyze their competitors. Since no one really knows what their ultimate intention is—and for what price they might sell it, or to whom—could farmers be underselling themselves by offloading data too soon?

Wade Barnes, CEO of Farmers Edge, thinks farmers would be short-sighted to sell their data now, for a dollar or two an acre, when there could be a more lucrative use down the road. “I grew up on a farm where my grandparents sold their oil rights for taxes, and now there’s oil wells all around them,” Barnes said at the AgTech conference in Boston.

That’s not to say no one will buy it. At the same conference, Renée Vassilos, an agri-business consultant, mused that small-scale biologics companies, unable to test at the scale of Monsanto or Syngenta, could be a potential customer for farm data. Other possible buyers could be food retailers, such as Walmart or Kroger, that want more information about the ingredients going into their private label products, for instance. 

For now, Tatge’s mum on that. “Nobody wants to admit they’re first,” he says.

The data store, which currently offers farm data from one million certified acres, mostly in the Corn Belt, is now open for buyers.

Correction: This story initially stated that farmers using Syngenta’s AgriEdge software submit farm prices and inventories from other companies. In fact, it is farmers who participate in a Syngenta program called Sustainable Solutions. We regret the error.