Agroforestry 101: Everything You Need to Know
The practice of agroforestry, from a broad perspective, is farming with trees, but looking at it more closely, it’s a land management system that capitalises on the biological interconnectedness of trees, crops and livestock to create thriving ecosystems.
While it’s starting to gain wider appeal, agroforestry is not new and was one of the earliest forms of agriculture, with Indigenous people practicing these systems as part of their traditional ecological knowledge for generations.
Currently, agroforestry and its ability to sequester carbon has made the practice at the forefront of sustainable agricultural systems that can not only help the world reach climate goals, but also diversify income for farmers, as well as provide opportunities for food security, soil protection, wildlife habitats, and community empowerment.
So how exactly does it work? First, some quick facts, before we break it down.
- Agroforestry methods protect soil, animals, crops, and homes from extreme weather, while also improving water quality.
- It can be good for local economies by producing useful products such as: food, fiber, wood, floral and medicinal botanical products.
- It improves pollinator habitat. Plant pollination by animals is integral for healthy ecosystems with 85% of the world’s flowering plants dependent on it for pollination.
- It’s a good mitigator for climate change as these methods help sequester greenhouse gas emissions.
Environmental Benefits of Agroforestry
According to the World Resources Institute, the U.S. alone could use agroforestry to remove around 156 million metric tonnes of carbon dioxide a year, and sequester 6 gigatons of carbon a year globally. But this isn’t all that agroforestry does for the environment, nor is it just one system.
Agroforestry actually involves five different systems, some of which carry varying degrees of intensity. These methods are often combined to protect soil, livestock, crops and homes from extreme weather, while improving water quality and soil quality, and nutrient density in food.
Those systems are:
These involve single or multiple rows of trees or shrubs that are expressly used for environmental purposes, like controlling wind erosion and protecting wind-sensitive crops, particularly during increased droughts or other extreme weather. These also help to create microclimates to help abate increased temperatures. They also control pests by creating more of a wildlife habitat.
These are trees, shrubs and vegetation that are established and managed adjacent to streams, lakes, wetlands and ponds. This helps reduce pollution from adjacent land uses that through surface run-offs end up in the water supply, which in turn enhances aquatic habitats, increases the storage of plant biomass and soils, as well as stabilizing streambanks. Also during extreme weather events these help to reduce flooding and soil erosion.
Sometimes also referred to as “intercropping,” alley cropping involves planting rows of trees with a companion crop in the middle. The trees help reduce surface water runoff and erosion, which leads to improved soil health and fertility. They also minimize wind erosion. Depending on crops, it can create microclimates that bring about higher yields and better wildlife habitats.
Multiple crops that can be planted in these conditions can also bring about more opportunities for farms to create income that isn’t always provided with mono-cropping.
This involves the intentional combination of trees, foraging plants, and livestock. Besides being more profitable, while waiting for nut or timber harvests, nitrogen-fixing forage species and animal manure help improve soil and tree nutrition. Grazing also controls competing vegetation and reduces fire hazards. Both silvopasture and windbreaks can also provide much-needed relief for livestock in fluctuating temperatures.
Silvopasture also has the ability to help reduce methane emissions from cows.
This is the cultivation of edible, medicinal or decorative crops beneath the protection of native or planted tree canopies, and are managed for wood and understory crop production. The understory is the underlying layer of vegetation beneath the shade of the trees (which are called the overstory) that creates a special microclimate that could increase soil quality and yields. Some examples of crops that can be planted can be herbs for essential oils (lemongrass, patchouli), spices (cinnamon, ginger, turmeric), fruits (berries), root vegetables (yams), herbs (oregano, basil), mushrooms (culinary and medicinal), certain nuts (beechnut, hazelnut), and other vegetation like ferns, moss, and ornamental plants.
The shade that the trees provide for the understory affects air temperature, humidity, soil temperature, soil moisture and wind movement which combine to conserve moisture in plants, reduce water usage, protect crops from temperature fluctuations, and suppress invasive weeds.
Agroforestry and Water
Agroforestry improves water retention and availability for farmers. Trees and shrubs have the capability to absorb water through the leaves, then send it into the air as oxygen and water vapor, while also pushing the water down through their roots, to filter out anything harmful as it goes back into the groundwater.
Agroforestry can also help work against species extinction by reducing flooding and soil erosion, which causes eutrophication of lakes and rivers. Eutrophication is when the environment becomes too enriched with nutrients, it increases the amount of plant and algae growth, which results in algal blooms, dead zones where water lacks oxygen, and fish kills.
Agroforestry and Natural Pest Control
Growing evidence supports that the usage of chemical pesticides not only harms the health of humans and soil, but they can kill wild animals, and disrupt their hormones which affects their behavior and ability to procreate. This can happen directly or indirectly through pesticide drift, secondary poisoning, groundwater contamination and runoff into local bodies of water.
While the USDA claims that certain agroforestry methods can block pesticide drift from contaminating waterways, and killing off pollinators, agroforestry itself can provide natural pest control to diminish the need for chemicals in the first place.
With methods like alley cropping, it reduces crop visibility, interferes with pest movement, which bars against infestation;’ it also uses plant diversity to dilute pest hosts, and creating a more favourable habitat to beneficial insects, all of which benefits the local ecosystem.
Agroforestry and Wildlife
Agroforestry systems can create a thriving habitat for a lot of wildlife, much of which has been displaced over the years due to practices rooted in colonialism which involved heavy deforestation and fragmentation of natural habitats to make room for conventional agriculture practices like monocropping and other kinds of modern development.
By introducing bees into agroforestry systems, they do the necessary job of pollination for a lot of crops and can help vastly increase crop yields. These habitats also attract other seed-dispersing animals like birds, or other creatures like moles and ants that help aerate the soil, which helps allow plants to take root and consume the most beneficial amount of nutrients to grow abundantly. It also helps attract predators who can take care of seed-eating mice or other pests.
Economic Benefits of Agroforestry
Small farmers seem to receive the most profound impact from the use of agroforestry. Better soil quality could help them increase their yields bringing about food security and more income. Also planting diversified crops around trees used for wood can allow for more income as well while waiting for the right time to harvest the wood.
In the U.S., according to a published study by the USDA’s National Agroforestry Center, still there are some blockages to success due to lack of land access and long-term leases. There was also a need for more information and access to markets and marketing for products.
Hawai’i’s Ulu Cooperative is a successful example of an ulu (breadfruit) agroforestry restoration project, which has grown to a large collective of farmers, and an online marketplace for a variety of products bringing about more local revenue instead of heavily relying on imported food.
In parts of South America, Inga Alley Cropping has taken over for slash-and-burn subsistence farming, which involves farmers cutting down and burning a patch of rainforest to have an area of fertile soil to grow food. The soil’s fertility doesn’t last long with maybe can grow a year’s worth of good crops, but there is an inability to grow anything down the line, which would propel the farmers to burn down more sections of rainforest.
Inga Alley Cropping, was introduced by ecologist Mike Hands after years of research to stop rainforest destruction and provide more sustainable solutions for farmers.
The Inga species is a nitrogen-fixing tree that can maintain soil fertility annually and doesn’t need fertilizing. The trees are pruned at chest height, and their leaves stripped to use as mulch protecting the soil from weed growth. The larger branches are used by families for firewood to cook. The crops are then planted and the Inga trees recover, providing crop protection from the sun. Eventually, the system provides a reliable crop every year.
The Inga alley cropping has created jobs, empowered women, kept resiliency through drought, and helped stop the need for farmers to feel like they had to migrate to the US to provide for their families.
Policy and Funding
More interest in agroforestry seemed to be on the rise in the 1970s due to the deteriorating economy in the developing world, deforestation, land degradation and population pressures. This, coupled with an expanding interest in agriculture in terms of the environment has begun to lead to policy changes and generous funding opportunities across the globe.
More than 60 countries currently recognize agroforestry as one of the primary tools to mitigate climate change.
In 2014, India became the first nation in the world to launch a National Agroforestry policy, which invested what would be around $33 million USD to mitigate climate change and improve agricultural livelihoods by addressing increased demand for timber, food, fuel, fertilizer and more, while also creating jobs and more income.
From 2015 to 2019, there has been a 2% increase in forest and tree cover, 1.8% of which is outside of forests, and trees grown outside are producing more than 70% of the countries timer requirement reducing pressure on forests, said Dr. Javed Rizvi, Principal Scientist of Center for International Forestry Research and World Agroforestry.
The policy also focuses on small farmers, which comprise about 80% of India’s farming community. Small farmers seem to receive the most profound impact from the use of agroforestry. Better soil quality helps increase yields bringing about food security and more income. Also planting diversified crops around trees used to wood, can allow for more income as well.
In 2019, Nepal became the second country in the world to adopt an agroforestry policy wanting to follow in India’s footsteps.
Also, announced during the UN Climate Summit in October, a group of NGOs secured funding for a project called Grand African Savannah Green Up whose goal is to capture 20 billion tons of CO2 with agroforestry systems by 2050 across Tanzania, Uganda, Malawi, Zambia, Kenya and Ethiopia.
Most recently in the US, the USDA also allocated $60 million to the Nature Conservancy and multiple partners to fund a five-year project to advance agroforestry in 37 states across the eastern US and Hawaii.
Food Sovereignty and Food Security
Through the histories of many cultures, colonisation upended Indigenous food-ways, trading deeply spiritual traditions, identities, and intimate knowledge of sustainable land stewardship, for profit.
Now as modern food systems are collapsing, and there are more governments acknowledging the importance of Indigenous land knowledge and investing in those practices, those who have been practicing them in spite of it all have seen it as an act of resistance.
In Costa Rica, the Indigenous Bribri women maintain their ancestral agroforestry practice called “fincas integrales” in the midst of Talamanca, which has been one of the country’s seats of monoculture since the 1500s.
The Bribri are one of the few matrilineal societies in the world, where land is handed down from mother to daughter, and whose many plantings of diverse crops are making them nearly self-sufficient. One of their main crops is cocoa, which is central to cultural practices.
“Indigenous Bribri fields are the opposite of monoculture: their presence is a political act,” Kattia Acuña, a professor of sociology at the University of Costa Rica told Mongabay.
Agroforestry and Women’s Empowerment
According to the UN’s Food and Agriculture Organization, female formers in lower-income countries represent 43% of the agricultural labor force, but represent 13% of landowners due to less access to credit, agricultural inputs and extension services, and that productivity could increase if they had the same access to men.
To some, agroforestry could be the door to more equality and has already been working with women around the world. Programs in Kenya, Indonesia, and India are run and led by women.
In Ratmate Village in Nepal, where men usually go out of town to work, women farmers in the district formed a cooperative and turned to agroforestry to sustain themselves more. With the help of an NGO, they began raising livestock (goats and bison), and growing a variety of fruits and vegetables.
In Rwanda, a women-led cooperative called Jyambere Munyarwanda recently planted over 20,600 trees for agroforestry purposes.
Urban Food Forests and Edible Landscapes
In cities and other more densely populated areas, urban food forests are starting to pop up as an answer to food security and access to healthy nutritious food, while also improving the environment.
These food forests show up in parks, schoolyards, and other non-traditional areas, and are taking place all over the world.
Here are a few:
Brown Mill Urban Food Forest
Located in Atlanta, in what has been labeled a food desert, the city wanted to change it, believing 85% of its citizens should live within a half mile of fresh, healthy food. This food forest produces a diversity of nuts, fruits, vegetables, and herbs, while also teaching sustainable food production through workshops and volunteer work.
In Budapest, Hungary, Cargonomia is a community cooperative that turned a dried-out wetland into a food forest, then by using bike messengers, deliver the food to residents in the area. It’s maintained by a group of volunteers.
In New York City, to combat the shortage to access fresh food and legality issues of picking food on New York’s public land, Swales Founder and artist, Mary Mattingly started a food forest on a barge, creating a floating food forest that she would dock at ports all around the city to provide free access to food.
In Mexico City, one of the country’s most densely populated cities, this group has an edible forest, seed bank, workshop programs about urban agriculture projects, and school programs to educate children about sustainable food.
Other Agroforestry Organizations
World Agroforestry – The International Council for Research in Agroforestry (ICRA)
The World Agroforestry ICRA is an international center for the science and development of agroforestry methods that does research to provide to governments, farmers and other agencies the ability to use trees to make livelihoods more sustainable. Their research spans the Global South in 44 countries.
National Agroforestry Center-United States Department of Agriculture
Starting in 1992 in the U.S. Farm Bill, the goal of this center is to provide leadership through research and science-based outreach, while working with farmers, ranchers, forest landowners, Tribes and other communities to accelerate adoption of agroforestry practices throughout the states.
This nonprofit focuses on working with farmers and scientists to provide the foundation for widespread agroforestry adoption in the Midwest United States.
Agroforestry Net, Inc.
This nonprofit’s website is a wealth of educational materials and design tools for sustainable agroforestry systems. It contains both free materials and links to books on the subject, as well as a blog called The Overstory that has several contributors.
An exhaustive list of other programs around the world can be on their website here.
While a lot of food systems have been collapsing and contributing to environmental catastrophes, many all over the world are looking to and investing in the ancient systems of agroforestry to create sustainable solutions not just for our environment, but for the livelihoods of farmers as well as for providing more access to nutritional, healthy food to local communities.