(This article was recently published as “Harvesting Nature’s Energy” in the Field Naturalist Program‘s Ecolog magazine – enjoy!)
This winter, I spent a day with Joel Salatin, a farmer from the Shenendoah Valley of Virginia, and heard him speak about sustainable agriculture and local food systems. Joel and his family’s farm, Polyface, was made famous by Michael Pollan’s bestselling book The Omnivore’s Dilemma and further popularized by the documentaries Fresh and Food, Inc. Polyface Farm raises a wide range of livestock – cows, pigs, rabbits, chickens, and turkeys – for meat and eggs. Through sophisticated rotational grazing, Polyface’s systems grow topsoil and restore healthy, diverse pastures in a landscape heavily impacted by 200 years of deforestation and overgrazing. The farm has been widely recognized as a national model for diverse, local, “beyond-organic” agriculture, and Joel is an increasingly sought-after speaker and teacher throughout the US and beyond.
In addition to their well-known grazing practices combining cows and poultry, Polyface also pastures pigs in oak woodlands for part of the year. During this period, short-time-frame rotations build topsoil and mimic the periodic disturbance of the oak forest’s natural fire cycle that’s been suppressed for centuries. Meanwhile, the pigs fatten for the winter on acorns. Joel described how prairie and savanna species are returning to the understory of these woodlands, invited out of dormancy in the seed bank through the pigs’ disturbance cycle. This “pigs in the woods” system is a form of agroforestry, a land use pattern with an ancient history around the planet.
Agroforestry can be loosely defined as “trees with agriculture”, and implies a diverse and interconnected system, rather than a monoculture of trees such as an apple orchard. One type of agroforestry is silvopasture (animals under trees) such as Polyface’s pigs pastured under oaks. Two others are alley cropping, or growing tree crops in between or above other crops (such as berries, flowers, or vegetables), and forest farming, or growing shade-tolerant crops in the understory of forests. Some references also define riparian buffers and windbreaks as forms of agroforestry, since they combine trees with conventional farming practices.
Agroforestry practices are best known from the tropical world, where multi-thousand year traditions of tree-crop agriculture still provide for millions of peoples’ livelihood. The history of agroforestry in North America, however, is much less studied and documented. In her groundbreaking book Tending the Wild: Native American Knowledge and the Management of California’s Natural Resources, Dr. M. Kat Anderson of UC-Davis documents the traditional land management practices of indigenous people throughout California. These included extensive management of oak woodlands, hazelnut thickets, desert palm groves, and other traditional tree crops. Management techniques included clearing, burning, pruning, transplanting, and coppicing tree crops to produce heavily and regenerate over the long term. When I met and spoke with Dr. Anderson several years ago, she emphasized how nearly every “wild” landscape in California has a pre-colonial history of indigenous management. The beauty and abundance of the California seen by John Muir was, in part, a result of these traditional land use practices.
This story can be found in the history of the Northeast US as well. Native people managed oak, hickory, chestnut, and butternut forests through clearing and fire; burned blueberry barrens and blackberry thickets to remove encroaching trees and renew the berry shrubs’ fruiting wood; and maintained meadows and prairies for growing crops and hunting game along the coast and in river valley intervales. The open, park-like hardwood forests of southern New England, cut for building, fuel, and tannins in the colonial period, had been shaped by many generations of native peoples’ management. The rich valley soils that European settlements depended on had been maintained and improved by centuries of traditional agriculture.
What does this history of native agroforestry and ecosystem management suggest for modern-day land use? First, it points towards reclaiming a more whole version of ecological and social history, and decolonizing conventional histories that marginalize the experiences and accomplishments of native people. Second, it suggests that modern farmers and land managers might look to traditional land use for new inspiration in navigating towards sustainability. One place to start is to match the uniqueness of a landscape with regenerative practices suggested by the land’s older history. Floodplains can grow corn and potatoes, but they can also grow walnuts, fruit trees, and perennial vegetables like Jerusalem artichoke and ostrich ferns. Thin upland soils can support marginal pasture land for sheep or cows, continuing the overgrazing of the 19th century, but they can also support drought-tolerant native perennial crops such as hazelnuts and many species of berries. Richer midslope soils can support orchards, pastures, gardens, or hardwood forests – but those elements can also combine to create powerfully multi-functional working agroforestry landscapes.
Sugarbushes can grow a wide range of full-shade crops in their understories, including mushrooms, ramps (also known as wild leeks), and valuable medicinal plants. Pasturing livestock under widely-spaced timber or nut trees can reduce the animals’ heat stress while producing multiple economic yields from a single plot. Orchards can be diversified with disease-resistant fruit species and understory crops of berries and cut flowers, reducing pest pressure and increasing economic and ecological resilience. These polyculture systems are complex, but years of study, trialing, and relearning by modern agroforestry “re-pioneers” in the Northeast have begun to reveal simple, successful patterns ready for more in-depth experimentation. And slowly, steadily, diverse tree-based agriculture is taking root again in pockets throughout the Northeast.
I’ve been exploring agroforestry for most of my adult life, and I’m convinced that it offers more than just a “new” (and old) form of agriculture. It also offers a worldview shift away from an extractive, disconnected relationship with the land. The diversity, complexity, and long-term nature of agroforestry systems can help to create participatory, mutually beneficial relationships with the land instead. Boundaries between “domestic” and “wild,” and between people and nature, can begin to blur and dissolve. We may be able to recover something ancient and essential through bringing trees back to our farms, and our farming back into the forest. I’ll meet you out there, on the edge in between.