By Patrick Shults, Extension Forester, Washington State University, email@example.com
Silvopasture, forest farming, agroforestry … you may have heard these terms thrown around before. But what do they mean?
“Agroforestry” in its simplest definition is a land management method that integrates forestry and agriculture into the same production system (“agriculture” + “forestry” = agroforestry). This means that the different parts (trees, livestock, crops) are intentionally managed together in a way that promotes positive interactions and minimizes competition.
When done correctly, agroforestry can both diversify and maximize production for a landowner while improving soil quality, wildlife habitat, biodiversity, and a host of other ecosystem services.
While it may seem like a new concept, it is only newly popular in the U.S. and other temperate climates. The concept of agroforestry is actually quite old and has been used by native cultures for centuries, including in North America.
In tropical climates, it continues to be a popular form of land management for sustainably producing food, fiber, and fuel on small plots. However, on-the-ground practices look quite different in temperate climates compared to the tropics.
I’ve listed out the five most common agroforestry practices used in temperate countries and given them brief descriptions. Though some are geared towards agricultural producers who may want to introduce trees to their cropping systems, all offer opportunities for forest owners to diversify what they do on their lands.
Windbreaks (or wind rows) are the first modern agroforestry practice to take place in the United States and were widely used during the Dust Bowl in the 1930s to reduce soil erosion in the Midwest.
This practice involves planting single or multiple rows of trees and/or shrubs which modify wind movement in your cropping system. Besides reducing erosion, they can also protect crops from damaging winds, reduce pesticide drift and livestock odors, provide wildlife habitat, provide fuelwood, and, in some cases, even improve crop production by regulating soil and air temperature.
Riparian Buffers and/or Forest Farming
Another practice that primarily serves a “protective” purpose with additional benefits, riparian buffers are used to reduce pesticide and fertilizer runoff into waterways throughout agricultural lands in the Midwest. This requires a buffer of trees, shrubs, and ground flora surrounding streams, ponds, wetlands, and other important water resources on your property.
As forest owners in Washington State, pesticide and fertilizer runoff may not be as big of a concern. Moreover, you may already have a mandated forested buffer on your stream if it is considered fish-bearing.
Regardless, buffers like these protect waterways effectively and also serve as an opportunity for another agroforestry practice, forest farming. In the Appalachians and Midwest, forest farming often involves manipulating the forest canopy to foster valuable native plant species that require a shaded forest setting, such as ginseng or goldenseal.
In the Pacific Northwest, this practice could be used to produce non-timber forest products like berries, mushrooms, fuelwood, and valuable floral products.
Likely the most common existing agroforestry practice for landowners in Washington state, silvopasture is the integration of livestock, trees, and forage. Although they may not call it silvopasture, many landowners run their livestock through their woodlots in both Eastern and Western Washington.
When done more intentionally, silvopasture provides considerable benefits to producers interested in selling both timber and livestock products. Trees provide protection and help to regulate air temperature which allows livestock to expend less energy heating and cooling their bodies.
The reduced stress for the animals can lead to greater milk production, reaching target weights quicker, and higher conception rates. Additionally, it allows a rancher to produce a long-term timber product or a forest owner to produce short-term income from livestock.
Although from both perspectives it may mean raising fewer cattle or fewer trees, the diversified and combined income can surpass that of growing only trees or raising only cattle.
Implementing silvopasture can be tricky, particularly in Western Washington, where the soils are more susceptible to compaction. More resources are available at the end of this article.
This practice involves growing high-value timber, veneer, or fruit and nut trees at a wide spacing to create “alleys” in which you can produce agricultural crops. In the Southeast, where agroforestry is increasingly popular, this may mean growing things like corn, soybeans, or tomatoes between rows of black walnut trees. In Washington, this may mean growing crops between rows of Douglas-fir, Ponderosa pine, or other native species.
Alley cropping is yet another way for landowners to diversify and increase income on their lands while sacrificing minimal growing space for trees. When done correctly it provides short and long-term products, improved soil nutrient cycling, biodiversity, wildlife habitat, and, in some cases, improved crop yields.
These five practices are considered the pillars of temperate agroforestry, but truthfully it is a wide umbrella with significant room for creativity, which appeals to some landowners.
Every parcel is unique and comes with special challenges. The flexibility of agroforestry allows landowners to find the approach that best fits their situation.
Why Should a Forest Owner Care?
Agroforestry is not for everyone.
But for landowners looking to diversify their production for commercial or personal use, agroforestry may be a viable option to do so without sacrificing significant tree-growing space. Agroforestry practices are catching on throughout modern and developing countries because they can often create a “win-win” scenario that makes both the landowners and the land more resilient to economic and environmental changes.
Despite their many benefits, these practices can be difficult to implement and require considerable forethought, planning, and, often, years of trial and error.
Because it is a relatively new area of research and every situation is unique, there is often limited information and recommendations available to landowners. This is especially true in the Pacific Northwest, which has trailed behind areas like the Midwest and Southeast in widescale implementation.
So, while it is likely not a good idea for an inexperienced landowner to turn their entire 20-acre forest or farm into an agroforestry operation at once, I would encourage interested landowners to do their research, seek professional help, and begin experimenting in small ways.
If you’d like to read more, below are links to available resources and publications. For the very interested folks, check out the 2019 North American Agroforestry Conference in Corvallis this June.