The Values in Agroforestry
Should we consider replacing traditional agriculture with it?
There is a new buzzword in town and it’s agroforestry. You have probably heard it once or twice in the context of climate change and food security. In our modern world it was more established around the 1970s. However, historically, agroforestry has existed since humans learnt the art of domesticating plants and animals after leaving hunting and gathering habits.
The U.S. Department of Agriculture defines agroforestry as “the intentional integration of trees and shrubs into crop and animal farming systems to create environmental, economic, and social benefits”. For years, traditional agricultural practices cleared out forests for farmland use by cutting down and even burning down forests. It is estimated that agriculture and deforestation contribute to a third of the greenhouse gas emissions. This newly-adaptation of the agroforestry practice provides a fair chance to society and the planet.
I know I am putting a lot on “the shoulders of” agroforestry, but here me out, there are plenty of benefits in it that our society should consider while adopting the practice.
Let’s talk specifics — What are its benefits?
One of the many environmental benefits of agroforestry is carbon sequestration. Carbon sequestration is the process of removal and storage of carbon from the atmosphere into what is called carbon sinks (like oceans, vegetation, or soils), done through physical or biological processes. By reducing the amount of carbon dioxide in the atmosphere we can mitigate the effects of climate change. The incorporation of trees or shrubs in our farming methods can increase the amount of carbon sequestered vs just in a monoculture field of crop plants or pasture.
This is nature we are talking about, so the potential of agroforestry systems to sequester carbon varies depending upon the type of species composition (the mixing types of trees), age of the tree species, geographic location, environmental factors, and of course the management practices. Various case studies were conducted around the world, all of them further add to the growing body of literature that indicates agroforestry systems have the potential to sequester greater amounts of above and belowground carbon compared to traditional farming systems.
That’s not all, agroforestry helps in soil enrichment. Our soils are under enormous stress in terms of farming production resulting in them being depleted of nutrients, which renders them infertile and vulnerable to degradation. The Global Assessment of Human-Induced Soil Degradation (GLASOD) found that 15% of the world’s lands have degraded due to human activity. Agriculture and deforestation are two of the main causes of this degradation. Soil degradation can lead to the reduction of soil productivity (less crops or not so healthy crops) or even the impossibility to grow plants (ie less food). When managed well, trees have a great capacity of maintaining soil fertility by building up organic matter and mediating nutrient cycling.
Agroforestry methods allow soils to be richer in nitrogen, phosphorus, potassium, calcium and organic carbon. All because trees are more efficient at extracting nutrients from deeper soil layers than annual crops with shallow roots. Deeper and stronger root systems of trees reach nutrients that would be unavailable to other plants. They incorporate these nutrients into their leaves, and will release them during the process of decomposition after leaves have fallen on the ground, leading to the enrichment of the upper soil layer and enhancement of growth of healthy crops. Plus, trees have a longer growing season than most agronomic crops, which increases nutrient use and use efficiency in an agroforestry system by capturing nutrients before and after the cropping season.
Soil is not the only beneficiary from agroforestry, air and water quality are positively affected as well. Starting with air and air quality — as we all know trees absorb carbon dioxide and release oxygen. But air is also wind & wind gust that farmers should consider in their processes. According to a study in Brazil, trees planted as windbreaks have the capacity to reduce wind speed by nearly 50 percent. Which protects the crops from breaking or falling down, especially during the ripening stage when they are heavy.
We take it for granted, but trees reduce noise pollution, mitigate odor from concentrated livestock operations, and create buffers that filter airstreams of particulates by removing dust, gas, and microbial constituents.
As for water, trees with deep rooting systems in agroforestry methods can improve ground water quality by serving as a ‘‘safety net’’ whereby excess nutrients that have been leached below the rooting zone of agronomic crops are taken up by tree roots. These nutrients are then recycled back into the system through root turnover and litterfall, increasing the nutrient use efficiency of the system.
Our next benefit is biodiversity conservation. Ecosystems and species are important in sustaining human life and the health of our planet and they are disappearing at an alarming rate. Scientists and policy makers are becoming increasingly aware of the role agroforestry plays in conserving biological diversity around the world. By applying the agroforestry methods to our farming we help in the process of conserving biodiversity. How? Agroforestry provides habitat for species that can tolerate a certain level of disturbance; It helps reduce the rates of conversion of natural habitat by providing a more productive, sustainable alternative to traditional agricultural systems that may involve clearing natural habitats; Agroforestry also provides connectivity by creating corridors between habitat remnants which may support the integrity of these remnants and the conservation of area-sensitive floral and faunal species; And last but not least, it helps conserve biological diversity by providing other ecosystem services such as erosion control (ie wind or water erosion) and water recharge, thereby preventing the degradation and loss of surrounding habitat.
What about the people?
My vision in tree planting is planting with communities (stay tuned for the next article on this topic). Unlike mass tree planting programs, the idea in bringing communities together to plant trees infused to their ecosystem, can help in both mitigating climate change and helping those communities prosper. Agroforestry falls under this criteria. How? It is usually the local community that works those lands. Relay on it for food security, financial stability, and job security.
While with traditional agricultural methods farmers often rely on the production of a single commodity, which makes them vulnerable to price fluctuations. This instability in food security is what agroforestry methods improve. Agroforestry is placing an emphasis on integration of and interactions among a combination of elements rather than just focusing on each element individually (mix of various crops and fruity trees, in addition to local trees), and therefore the provides profit year round.
Furthermore, planting trees together with crops or on pasture lands help fight hunger and malnutrition, as trees are a source of food (Growing trees which produce food provide easy access to nutritious food for households.), medicine (trees and plants grown on farms are important sources of medicines and natural remedies, which help improve people’s health), fuel and non-wood products that can be either directly consumed/used or sold (the trees felled or their residues can be used as wood energy for cooking and/or heating, while the leaves, and other parts of trees, can serve as forage for livestock). In addition to selling crops, with better management of trees on croplands allow farmers, or farmer cooperatives, to sell the amount of carbon sequestered for carbon credit in the carbon credit markets, obviously for their profit.
It may look like a lot, but these are just some of the benefits of agroforestry. The change to this practice may not be easy, as designing and managing an agroforestry system with conservation goals would require working within the overall landscape context and adopting less intensive cultural practices to achieve the maximum benefits. But it’s worth the effort as it can help the environment and support the people.