What Is Silvopasture? Key Principles

Silvopasture, a portmanteau of the Latin words "silva" (forest) and "pastura" (grazing), is a form of agroforestry that the U.S. Department of Agriculture describes as "the deliberate integration of trees and grazing livestock operations on the same land." This regenerative farming method benefits both the land and animals—think free organic matter (i.e., manure) for the soil and a cool, shady environment for livestock—not to mention the farmer, who may use the trees to supplement income from livestock and vice versa.

Silvopasture has been lauded for its carbon-capture potential, which could help reduce the impacts of climate change, but it certainly isn't a perfect solution. Learn more about this land-use practice, its key principles, and its benefits and challenges, ahead.

Key Principles of Silvopasture

Silvopastures can be established either by introducing trees into a pasture or introducing livestock to an existing woodland. Whichever the case, healthy and successful silvopastures should have these basic principles in common:

1. Trees Are Matched to Soil Type and Climate

If planting trees in a pasture, the trees should be suited to the environment. Native species are best because they thrive with as little effort and few resources as possible, plus they benefit native fauna such as pollinators. You also want species that provide valuable fodder for the animals—such as protein-rich black locust (rivaling the nutrition of alfalfa) and willow, whose tannins have been proven to ward off some sheep parasites.

The trees should also be diverse, lending to a complex ecology that provides not just diversity in the animals' diets but also wildlife habitat and some resistance to pests and diseases that would otherwise flourish in a monocrop environment.

2. Livestock Is Matched to Trees

Silvopasture is suitable for a vast array of livestock, from the standard—like cattle, sheep, goats, chickens, and horses—to the unusual—such as caribou, bison, and emus. In any case, livestock should be matched to the environment, taking into account the forage, climate, and, importantly, the trees' stage of life.

Cows, for example, are heavy and prone to trampling the roots of vulnerable juvenile trees. Their insatiable appetites and bulky statures are a recipe for disaster in orchards where they have access to low-hanging fruit. Sheep, goats, and pigs may not be as large, but they're hungry for bark. Put these animals in a pasture with saplings and they will most definitely wreak havoc. All of this to say that farmers must do their research when pairing trees with animals and make sure the forest environment is ready for grazing to avoid doing more harm than good.

3. Focus Is Split Between Forest and Livestock

Silvopasture is not a one-sided system that favors agricultural outputs for farmers; rather, it's a practice that melds animal husbandry with forest stewardship. In a silvopastoral system, outputs may suffer for the forest or livestock to thrive. The work involved here might include amending soil, managing weeds and taking other steps to protect trees, pruning, harvesting hay, and thinning the forest so that light can shine through the canopy and penetrate the forage. It's much more work than rearing livestock in open pastures and often takes more time to reap the economic rewards.

4. Animals Graze on Rotation

Though not essential to a silvopastoral system, a rotational grazing approach is best for plant health and growth. The alternative, continuous grazing, in which livestock graze in a pasture for an extended period, can lead to soil degradation and overgrazing of the most nutritious species. Rotational grazing involves moving the animals to allow the forage to rest, recover, and grow. This method is mutually beneficial, as the animals in turn get more diversity in their diets and less exposure to parasites.

Ecological Benefits of Silvopasture

The silvopasture approach is often exalted—including by the USDA—because of its potential to mitigate climate change and offset the environmental strains of animal agriculture. Here are just a few of the benefits:

• Carbon capture: One study found that pastures with trees sequestered about 27% to 70% more CO2 than pastures without.
• Soil quality: In another study, silvopasture soil contained more nitrogen and carbon even than woodland soil, which led trees to grow up to 5% taller, 35% larger in diameter, and 78% greater in basal area.
• Water quality: Trees reduce and slow runoff and trap pollutants like pesticides, fertilizers, and—especially important in an agricultural setting—livestock waste.
• Cooling benefits: Tree canopy helps reduce heat stress, lowering the temperature by up to 2.4 degrees Celsius per 10 metric tons of woody carbon per hectare, according to one study. This is an increasingly important benefit to silvopasture as temperatures continue to rise amid the climate crisis.
• Wildlife habitat: The diverse ecosystem a silvopastoral system provides helps feed and house a variety of wildlife from essential pollinators to mammals.
• Fire prevention: Grazing livestock can cause wildfires, but managed grazing can prevent them. The livestock grazes on and reduces the understory, which can act as "plant fuel for fire," one seminal book on silvopastoralism said.

Benefits to Livestock

Grazing livestock may reap the rewards of silvopasture, too.

• Dietary diversity: With a rotational grazing approach, livestock has continuous access to nutritious and diverse food types.
• Reduced risk of infection: Disease and parasites thrive in a monocrop environment. Moving livestock regularly halts the development and spread of outbreaks.
• Reduced heat stress: The same cooling effect that benefits the land also helps reduce heat stress in the animals, which improves their performance and overall wellbeing.

Benefits to Farmers

Besides the benefits to their land and livestock, farmers could gain the following from adopting a silvopastoral system:

• Income diversification: The main draw for farmers to adopt a silvopastoral system is perhaps the economic benefit of adding trees (or livestock, contrarily) as an income source.
• Enhanced aesthetics: Pastures with trees simply look better than those without (which, as a bonus, could boost property value).

Challenges of Silvopasture

Silvopasture comes with some drawbacks for both farmers and the environment.

• Time and energy: Trees take time to establish in existing pastures, and farmers must prevent livestock from grazing on the land while a healthy forest ecosystem develops. For the first two to three years, saplings require intensive weed suppression and competition control. Not until the trees are mature, after three or more years, will the fresh woodland be ready for grazing animals.
• Financial investment: Establishing a silvopasture system in an existing pasture costs $100 to $150 per acre, according to the USDA. That includes the cost of site preparation, seedlings, labor, and fencing, not continued maintenance.
• Reduced carbon-holding capacity: Turning an existing woodland into a silvopasture could reduce its carbon-holding capacity because livestock will inevitably compromise trees—at least some, in the beginning—and trees are often harvested as additional farm income.