By Steve Gabriel
This is an excerpt from Steve’s book Silvopasture, published by Acres U.S.A. Reprinted with permission from the publisher.
Since this is a book primarily about the practice of silvopasture, it is useful at the outset to offer an over- view of the key principles and approaches that are part of the system, regardless of the specific species or site context at play. Whether you choose to graze sheep in a Christmas tree farm, move cows through a walnut plantation, or graze chickens through an apple orchard, these elements are universal for successful silvopasture.
Silvopasture can be established in existing woodlands, or trees can be brought into pasture.
One of the nice aspects of silvopasture is that you can establish a system on almost any type of land. Of course, establishing it in existing forest is in many ways a very different process than bringing the trees into open pas- ture. The similarities and differences of establishment in such different contexts will be discussed in detail in chapters 4 and 5.
The only land types on which we might consider avoiding silvopasture are very sensitive areas such as wetlands and healthy, maturing hardwood forests that might be best left to their own process of succession. Given that silvopasture has an experimental aspect to it, working first on more marginal lands is the best way to begin, offering the opportunity to learn with lower stakes. In ecological approaches to farming, it’s good to practice precaution, easing into the development of novel systems, all while carefully monitoring for any adverse impacts.
Animals are matched to land type and successional stage.
It’s critically important from the outset that the appropriate animal is chosen for a given site in order to reduce the potential of inflicting damage on the landscape. Animals are incredible at what they do, but it cannot be overstated that they have just as much potential to do harm as they do good. While we will cover considerations for animals in depth in chapter 3, here is a short list of potential risks for given species:
Cows. Excessive stocking/duration with their weight could damage soil and tree roots, as well as cause erosion; also, they can easily destroy young trees.
Pigs could root and trample desired vegetation and make a moonscape of your woods or pasture in a very short period of time. Pigs are the most challenging animals to incorporate into silvopasture.
Sheep and goats. Depending on forage type, sheep and goats could overgraze the landscape and/or strip the bark off young trees, killing them.
Poultry could scratch or root down to bare soil and damage roots and plantings.
You can see from the above list that most of the problems can be avoided by doing proper assessment of the land and engaging with the animals to ensure they are moved before they do harm. The key elements of stocking rate, density, and duration in a paddock come into play here; they must be well designed, and redesigned each year, to optimize the system.
In addition to choosing the right type of animal for the system, careful selection of the specific breed is an essential task. Some breeds are able to utilize a wider range of forage and conditions, whereas others are not as willing to be as flexible. Chapter 3 discusses the role ani- mals play in silvopasture systems in much greater detail.
Animals are always on a rotation.
Grasses evolved alongside grazing herbivores, and while it might be surprising, they arguably benefit from being grazed so long as they have a rest period. For wild grazing animals, such rest is achieved when grazing animals need to move on to new places because of the threats predators pose or from seasonal changes to weather and climate. In the context of modern grazing systems, designated paddocks, the farmer, and electric fencing act as the “predator.”
When the animal consumes the top of a plant, a proportion of the roots are sloughed off or deposited into the soil, which contributes organic matter content. After plants are grazed, a rest period is critical to their recovery, where the shoots grow back. Overgrazing means these plants take a longer time to recover, while severe overgrazing means the plant might die alto- gether. Moving animals is also good for them, as they have reduced exposure to disease risks and receive the highest-quality food possible during the season.
The rotational process also benefits the farmer’s bot- tom line, as it’s been shown to improve the quality and quantity of forage on the pasture.4 More intensively managing pasture also allows you to feed more animals on the same amount of land. The clear promise of man- aged grazing comes in your ability to have more control over food for your animals, on-site, with the potential to increase the value of their feed and thus the number of animals and/or the amount of land and duration of the season that land can be grazed.
How long the organic matter remains in the soil, known as sequestration, is another matter altogether. Many rotational grazing proponents laud any practice of rotational grazing as an important way to address cli- mate change. But as always, the details matter. The soil type, climate, and bioregion, along with the variables of management, make it hard to be conclusive, and it’s an open debate among scientists.5 Some studies show net positive effects, while others show that all animal grazing systems are emitters of greenhouse gases, no matter the style or approach.6
Regardless of the climate impacts, rotational grazing is essential to a healthy pasture system. This aspect of silvopasture is non-negotiable, and is often the biggest hurdle for adopting the practice, especially by graziers who have been practicing continuous grazing for some time. Fortunately, advances in our knowledge and technology have made rotational grazing easier than ever before. Farmers new to livestock are almost always convinced from the start that rotating their animals is a good thing, though there are many details as to what a rotation can look like, including the size of paddocks, the duration of stay animals have in a given paddock, and so on. These considerations are discussed in chapters 3 and 6 in great detail.
Regardless of the specifics, it is the universal opinion of silvopasture advocates that animals should not be placed in tree-based systems if they will not be man- aged through rotational grazing.
Trees should match the soil type and microclimate and have multiple functions.
You could arguably plant trees for the sole purpose of shading the livestock, but why not aim a bit higher? There are so many choices in the temperate climate for trees that will do well in even the worst of soils, that provide not only shade but also a number of other pos- sible yields. Of course, the yields will depend on how the trees are managed and are often easier to “control” when you’re establishing a silvopasture in open field conditions versus an existing forest.
While you could choose any number of trees to plant into a silvopasture, there is a shorter list of trees that offer specific benefits in the context of silvopasture systems (see chapter 5). These trees are generally fast growing, hardy, and resilient to weather and climate. They often offer both a potential food value to animals and poten- tial wood and timber products down the road.
The goals of the farmer or landowner also come into play, as there is no use planting apple trees, for instance, if you don’t want to harvest apples. Some farmers want to establish the lowest-maintenance trees possible. Some want a yield of fruit in 3 to 5 years or of nuts in 5 to 10. And some are happy to plant timber species and wait 50 or more years to harvest. We will discuss options for tree species and weigh the pros and cons of each in chapter 5.
Forage and fodder should be diverse and support a resilient food supply for animals.
One of the largest opportunities in silvopasture is the creation of a wide range of ecotypes, which can support a wider range of grasses, forbs, herbaceous plants, and trees for animal feed. This gives animals a more diverse and healthy diet that is not only nutritious but also medicinal. In essence, the design of a diverse silvopasture offers animals a habitat that might resemble or even exceed their original experi- ence grazing in the wild.
Modern farming has greatly oversimplified the ani- mals’ experience of seeking food; in some operations animals only visit the feed bin for grain or hay. This not only offers animals a limited diet in terms of nutrition, but also starves their innate desire to seek out food in the landscape. Behavior specialists argue that this creates boredom in animals, which can lead to disease and to a lower quality in the final product. Ethics and markets also come into play, as animals have an innate right to live a good-quality life, and more and more consumers are lining up with their dollars to support farming practices that promote animal welfare. More on this in chapter 3. In addition to supporting the overall health and well-being of the animals, a focus on diverse forage also provides an economic incentive for the farmer. More diversity in feeds should reduce the feed bill, and also provide food in lean times, because tree-based systems can often buffer better against long-term drought and even excessive rain. Grasses grow on a bell curve, often peaking in early summer with lower production in July and August—unless the forages are shaded and can thus remain better quality for a longer period of time. The invitation to include trees into grazing systems is ultimately one to create more dynamic ecosystems for our animals to explore.
Careful matching of forages to the micro-envi- ronments on the farm is the challenge. For example, for most silvopasture in the eastern United States, cool-season grasses are utilized, as they excel in part- sun environments. Warm-season grasses are best for overly sunny or dry areas, or warmer climates. The trees effectively help retain optimal conditions for cool-season grasses throughout the summer months. This, coupled with the careful selection of trees that leaf out at various times and provide a range of shade conditions, can optimize production. For instance, black locust is a great silvopasture species, as it leafs out late in the spring, and when fully leafed out casts a mild shade, allowing the space underneath to be cool and somewhat shady but not to the point where grasses would be stressed for light. More on forage and fodder considerations in chapter 5.
The system is ideally optimized to stack inputs and outputs in both space and time.
The beauty in silvopasture systems is not in the parts but in the complex whole created by bringing all the parts together. Yet with complexity comes a challenge in management—this is indeed why agriculture in the United States and other industrialized nations has been on a general trend toward more straight rows, single-species monoculture, and rationed feeds. It’s easier to do the math. But as we will discuss, the benefits of creating a more complex ecology outweigh the time it takes to design, establish, and manage such a system. Each chapter in this book walks readers through the process, and helps make more sense of the complexities.
Be patient with yourself. Few of us are raised in cultures where we understand a more natural way of farming. Many are interested in the concept of a more complex ecology, yet find themselves overwhelmed and frustrated as they try to comprehend things. It’s wise, then, to start small and slow, especially if you are new to one or more of the two main aspects of this prac- tice: grazing and forestry. Draw upon the knowledge of others, and recognize that you’re in for a lifetime of learning. Get the foundations of grazing right from the start, then bring in the forestry aspects. The content of this book, along with the case studies of farms actively practicing silvopasture, will help paint a picture of how this can be done.
To keep learning about silvopasture, find Steve Gabriel’s book Silvopasture at the Acres U.S.A. Bookstore.
About the Author
Steve Gabriel is the coauthor of Farming the Woods, is an ecologist, educator, and forest farmer who has lived most of his life in the Finger Lakes region of New York. He passionately pursues work that reconnects people to the forested lands and supports them to grow their skills in forest stewardship.
He currently splits his time between working for the Cornell Small Farms Program as Agroforestry Extension Specialist and developing the farm he runs with wife, Elizabeth, Wellspring Forest Farm, which produces shiitake and oyster mushrooms, duck eggs, pastured lamb, nursery trees, and maple syrup.