This herd, however, is not quite as free-range as it appears.

All 70 of the animals wear what look like big, boxy cowbells around their necks. When one goat gets close to an invisible fence line the farmers set up on an app, the box emits a high-pitched tone, eliciting an immediate response. Any goat within hearing distance perks up, freezes, and then slowly moves away from the line, despite the lack of any physical barrier.

The system was created by a Norwegian company called Nofence, and Molly and Sam are among 43 pilot farms testing it ahead of an official United States debut expected in early 2024. And Nofence is just one of several companies getting into the virtual fencing game. U.S.-based Vence, which was acquired by veterinary pharmaceutical giant Merck Animal Health in 2022, has been slowly rolling out a similar system on larger cattle ranches across the West since 2019. Other systems, including eShepherd and Corral Technologies, are also in development.

Virtual fencing is gaining traction in American agriculture because it can save farmers time and money.  But it could also enable them to more easily adopt practices—and entire systems—that promote environmental benefits. When farmers are able to control how, where, and when their animals move between pastures, they can more easily accomplish ecological goals that might include increasing soil carbon, reducing water pollution, or incorporating trees. The technology also has the potential to rid the West of barbed wire that negatively impacts wildlife migration and adapt grazing to an age of increased wildfires by making it easy to keep cattle out of burned areas.

Given how few farms are using it, there are still many questions about limitations—like the absence of cell service in some rural areas, farmer acceptance, accuracy, and ongoing costs—but buzz about virtual fencing’s applications continues to grow. In September, a project dedicated to sustainable beef production in the Southwest created a Virtual Fence Forum for farmers on Facebook; in November, ranchers gathered in Arizona for a workshop on the technology.

“People have been talking about virtual fencing for a long time,” said Juan Alvez, an extension research associate at the University of Vermont’s Center for Sustainable Agriculture, whose expertise includes grazing management, “and now it’s just coming to market.”

More (Virtual) Fencing Facilitates Animal Movement

But since the couple took over about a decade ago, they’ve been looking to the future to make their goat dairy and cheesemaking operation more sustainable—both financially and ecologically.

In past grazing and milking seasons, which run from March through December, Sam regularly had to move fencing—sometimes every day—to keep providing them access to new fields with fresh plants and keep their waste dispersed across the landscape. He also had to construct pathways to move the goats back to the barn for milking.

“He was having to put out posts, roll out four wires. He put a lot of steps in, and it took a lot of hours,” Molly said of Sam’s efforts. Now, with the virtual system, “Sam can update the fence lines while he’s drinking his coffee in the morning.”

He does that using Nofence’s app, which creates and updates the boundaries by GPS, with no physical infrastructure other than the collars worn by the goats. Each collar is outfitted with tiny solar panels to continuously charge the battery, and Molly said it’s usually about a month until they have to take them off to charge them manually.

While physical fencing for cattle can be slightly less involved than for goats, since a single electrified wire will keep cows in place (most of the time), cattle grazers need a lot of fencing and frequent movement if they’re pursuing climate and other environmental goals.

To effectively build soil health, Alvez said, farmers and ranchers who use systems referred to as rotational, intensive, or mob grazing, should move their animals to new pastures at least once a day. While continuous grazing depletes pastures and overloads fields with waste, these alternative approaches build soil health by naturally spreading the manure, fertilizing new grass growth, and building healthy communities of microbes.

Traditionally, many farmers struggle to set up enough paddocks for continuous movement, because installing fencing can be expensive and labor intensive, Alvez said. “More paddocks versus less is always better for grazers and climate-smart goals, because you’re always moving these animals to a fresh pasture,” he said. “Fresh pastures mean most [of the other] pastures are in a vegetative state, often accumulating carbon from the atmosphere into the soil where it belongs.”

With virtual fencing, there’s an upfront investment, but adding new paddocks can be done on the fly, without additional costs. Nofence’s collars cost $299 each for cattle and $199 for goats or sheep, and come with a five-year lifespan. In addition, farmers then have to pay a monthly subscription fee that varies depending on herd size and other factors. It’s no small cost—for Georges Mill farm’s 70 goats, it would cost around $14,000 for the collars—but fencing, depending on the type, generally costs thousands of dollars per acre upfront, plus the added daily labor.

One drawback is that since the lines the system draws are not as exact as a physical barrier, farms may still need to put permanent physical fences up in places where a hard stop is needed, like along busy roads. At some, a physical fence creates the overall farm barrier, while virtual lines create pasture barriers.

The biggest limitation with virtual fencing, however, is that depending on the system, connectivity could be an issue. With Nofence, strong Wi-Fi is not required, but a cell phone signal is, and Meghan Filbert, the company’s adoption program manager, said that if a farmer can’t typically receive calls or texts in their pastures, the system won’t work for them.

That could be a major issue in lots of rural places, including Alvez’s neck of the woods in Vermont, where cell service often cuts in and out. It’s something he hopes will improve (and there are many efforts currently underway to improve broadband in rural areas around the country) because he believes his area could benefit more from virtual fencing.

“In areas where it’s more mountainous, with rugged landscapes and lots of marginal land, having this technology would really simplify the amount of paddocks you can establish,” he said. That’s because putting physical fencing in those places is more difficult compared to areas with flat, open terrain.

Controlling Grazing Near Water and Trees

In the field at Georges Mill, Horn said that a lot of land in the hilly, populated region is better suited for grazing than other types of agriculture and that he got interested in virtual fencing through his work making sure that grazing benefits the Chesapeake Bay watershed instead of contributing to its pollution. Continuous grazing that allows manure to build up can result in excess nutrients ending up in waterways, and cattle getting into streams can also deposit nutrients and contribute to erosion.

He sees the technology—which can enable more movement and control where animals are in relation to water sources and trees—as one tool farmers could use to better manage pastures.

“Well-managed pastures [are] good for water quality because we’re actually infiltrating more water, and there’s less runoff going down to our local creeks and streams,” he said. “If our local creeks and streams are cleaner, ultimately, the rivers—and as we go east, the Bay and everything else—they have better water quality too.”

Virtual fencing may also aid farmers in implementing agroforestry practices that reincorporate trees into farm systems and come with significant climate and biodiversity benefits. For example, a quick swipe of a finger on a virtual fencing app could allow a farmer to protect riparian buffers, strips of bushes and trees alongside streams that prevent runoff and support wildlife, from cattle until the plants are well-established.

That’s the application Alvez is most excited about, because the difficulty of putting up fencing that can contain animals and also protect trees as they grow is often a complicating factor in getting agroforestry systems off the ground.

And in a system where sheep are grazing in alleys between fruit trees, a farmer might try to put up a fence and encounter difficulties because of tree roots. “With virtual fencing, you could put the line six feet off the trees and still have the benefit of the shade for the animals and at the same time protect the trees,” he said.

The Way Forward for Virtual Fences

Alvez is working with a developer in Brazil to bring another product to the U.S. that works in a similar way but uses an ear tag instead of a collar. That system will also provide data like body temperature from the cattle that wear it, and Alvez hopes to begin using it as a research tool.

Back at Georges Mill, Molly and Sam didn’t opt to use virtual fencing in order to better incorporate trees and livestock, but during their pilot of the system, that happened naturally.

One recent morning after a thunderstorm, they moved the goats to a distant field across a road. Only after they got them there did they notice a cherry tree—which is toxic for goats—had fallen in a thicket within the field.

In the past, Molly said, that would have meant “moving the herd all the way back into the barn while Sam totally cuts it up and clears it out, because you can’t have any of the leaves around—if they eat them, they’ll die. It’s a huge disruption, a huge amount of time.”

This time, however, “We were able to just draw an exclusion zone around it and keep everybody off of it,” she said. “That was huge.”