Soil Searching: A Vermont farm finds sustainability through science and soil
By Noah Beckage
September 5, 2020
To cars and passers-by traveling down Mt. Philo road, the peripheral seas of grass are lush but unobtrusive under a deep September sky. Throughout this month last year, I spent my mornings wading through those tall pastures, the boonie hat on my head bobbing around the surface of the vegetative ocean like a khaki buoy. I made my way through the shoots of fescue, rye, meadow, and kentucky bluegrass, sampling plots and collecting data on the pasture’s health. I recorded species, average height and density of the vegetation, and any surface indicators of soil health such as the presence of moss or decomposing plant matter. As I knelt on the soil scribbling observations on a clipboard, I was transfixed by this vibrant agroecosystem of grass and earth.
I came out to these pastures to try to understand soil life and the impact it has on agriculture. I was working with Juan Alvez, a University of Vermont (UVM) plant and soil sciences professor and research associate with UVM Extension’s Center for Sustainable Agriculture. For his research, Alvez cultivated a partnership with Philo Ridge Farm, an agriculturally diversified farm in Charlotte, VT. Our shared role was to collect and analyze data on the farm’s pastures and soils, allowing us to better understand the overall agricultural ecosystem and make recommendations on how to sustainably foster its vitality. The farm managers, in turn, trust these recommendations in the eager hope of healthier soils, greater pasture yields, and, ultimately, healthier beef cattle—the farm’s trademark animal. So far, Alvez’s research suggests a holistic, ecologically-minded approach to raising pastures as the best practice for maximizing the well-being of both the farm and the land it cultivates.
“Don’t disturb soil; let life thrive, and encourage diversity,” is Alvez’s standard prescription for optimal soil health. As any ecologist knows, diversity of species is integral to an ecosystem's stability and overall vitality. Alvez explains that the same principle applies to the microecosystem of soils: “You want to have some balance of different microorganisms.” This balance is necessary to fulfill all the ecological roles required to maintain healthy soil, including nutrient recycling, soil cohesion, and the accumulation of organic matter.
Organic matter is any material in soil that is of an organic origin, such as living microbes, dead plant matter, or manure. It is the vital raw material that turns inanimate dirt into living soil. Its abundance is, Alvez asserts, "the gold standard of agroecology." That is because accumulating organic matter proportionally increases the amount of water soil can hold, turning a deluge that might otherwise risk flooding into a welcomed boost to pasture yield. “For every inch of water that the soil absorbs,” Alvez tells me, “you can grow an additional 200 pounds of [grass] forage.” Ian Johnson, the Assistant Livestock Manager at Philo Ridge, explains that when organic matter accumulates in soils, they “will take up water quickly and won't stay as waterlogged for as long. Then it will hold water better throughout dry periods." At a farm with over 200 acres of pastures, that extra inch of absorption goes a long way towards increasing resiliency and yield.
But soil is only one side of the agroecological coin; if organic matter is the gold standard, then animals, as Alvez puts it, "are the cornerstone of agroecology." Johnson is responsible for caring for the farm’s livestock, including “everything from calving, lambing, feeding, and watering up to organization around harvest and processing.” In the middle of that spectrum of responsibilities is one task that is critical for nourishing animals and regenerating soils: rotating the grazing animals from pasture to pasture. Since grass pasture comprises 100 percent of the diet for the farm’s sheep and belted cattle, constantly rotating the animals ensures that, in Johnson’s words, “every day they get a fresh paddock of grass that's sized to their needs for that day.” The key is having just enough pasture to cycle through so that animals always have fresh, mature grass. By the time the animals have come back to the field where they first grazed after about 30 to 45 days, “the grass has had time to regrow, and there's adequate food for [the animals] when they come back.” The grass is only grazed down to a minimum length that still allows the plants to utilize their photosynthetic tissue to regrow, rather than depleting the energy stored in their roots. This way, the pastures can regenerate themselves sustainably without draining the energy potential of the soil. The problem with leaving pastures on their own for too long without grazing animals is that “over time you get succession,” Alvez points out. This means that pasture species gradually decline, and the grazing cycle breaks down as fields slowly transition into forests; the grasses are outcompeted, unpalatable shrubs spring up, and eventually trees take root.
Thus the cycling between grazing and regrowth is essential to the regenerative agriculture of Philo Ridge. “There are a lot of names for it,” Johnson says, “but basically we're trying to build soil carbon and soil biology to grow a healthier forage mix so that we can raise healthier animals.” One of the ways the farmers at Philo Ridge have been trying to do just that is through introducing nitrogen fixers to the pastures, a recommendation initially put forward by Alvez intending to cycle a nutrient critical to plant life back into the system. "We've been adding a lot of legumes to the pasture mix, which is because they sequester their own nitrogen,” Johnson affirms. Since adopting this practice, the change in forage quality has been noticeable: “you can just see it in the rate of regrowth of the grass, the color, how lush it is, and the feel of the soil itself.” Johnson also points out how the vigor of the grasses has been healing some of the damage to the soil that has resulted from tilling in the past. This traditional agricultural practice tears up and churns soil under the false premise that manual aeration will increase porosity. Without such disturbance, pastures begin to thrive with greater access to nutrients and water. Johnson describes the vitality that has returned to the farm since ceasing tillage: “The grasses themselves are established better in the soil, their roots are getting deeper and breaking through some of the compaction and hardpan that had been left from previous tillage.”
Single-cell wide networks of fungal mycelia play one of the most crucial yet hidden roles in regenerating this vitality. In essence, they are able to bridge the above and below ground components of the agricultural cycle. Jessica Rubin, a graduate student in UVM’s Plant and Soil Sciences department and founder of the mycoremediation research collaborative MycoEvolve, emphasizes that "not only are [fungi] decomposers, intaking dead matter and turning it into elements that can be taken up to support life, but their mycelium also basically expand the rhizosphere—the root zone of plants—and access minerals, nutrients, and water that the plant can't get on its own.” In this way, the fungi mycelia act as a catalyst for the agricultural soil cycle, quickening the accumulation of organic matter and the recycling time of nutrients. Arbuscular mycorrhizae, the symbiotic fungal partner of legumes, never produce mushrooms; they remain underground and unseen. Unless torn up and killed by tilling, the mycorrhizae can, “release a glycoprotein called glomalin that helps basically sequester carbon and bring soil aggregates together,” according to Rubin. During a time of drastic global climate change, minimizing the carbon footprint and environmental impact of agriculture is a primary motive for Philo Ridge—and these fungi help do that.
That goal is part of the reason why the farm has been trying to revitalize the land through sustainable practices "from the beginning," says Johnson. Johnson is referring to the year 2012, when the current owners bought what was then a traditional dairy farm and began converting it into the diverse, sustainable operation it is today. Empowered by knowledge and research-backed science, they have been largely successful. “We're cycling a lot more of the nutrients on-farm. We don't have to bring in as much seed or fertilizer for the land base,” which he says is a direct result of “working with the land, growing perennial crops that are lower maintenance, and reaping that reward of what wants to grow here and what wants to grow within this system.” Professor Alvez is also seeing the effects of this transition in the carbon-holding capacity of the soil; the pastures are coming alive again, and, in a sense, breathing. “In the agronomical concept of respiration, your soil starts accumulating more carbon, sequestering more carbon. We measure that at Philo, and we have a net positive.” This measurement indicates that the soils and grazing animals are effectively removing carbon from the atmosphere and storing it within the Earth.
The sustainable agriculture at Philo Ridge has yielded resounding success for the farm and the environment. The farm serves as a model for other farms throughout Vermont: “I definitely see these practices spreading throughout the state as an alternative to [current] dairy management,” envisions Johnson. Alvez as well has bright hopes for the future of sustainable, small-scale agriculture in the state: “If you're willing to listen, if you're willing to learn new things, you can change for good and forever. You can pass your farm to your kids, and they can keep farming in the same way.” Like the herd of graceful belted cows I watched browse through verdure pastures during the late and lush summer, perhaps sustainable farms can also flourish and cycle through time, generation after generation.
