why agroforestry?

Slash-and-burn is used to clear forests for agricultural land. (Photo credit: Britannica Encyclopedia.)

Rural farmers in Mexico and Central America often clear forests for agricultural land, and the common method for clearing land is slash-and-burn. Slash-and-burn involves the cutting and subsequent burning of a forest to use the land for agriculture, and plots are abandoned when they are no longer seen as productive. This leads to rapid deforestation, destruction of valuable ecosystems, and the release of greenhouse gas emissions.

Agroforestry is a farming system that integrates crops and/or livestock with trees and shrubs. An age-old practice, observed for thousands of years around the world, agroforestry is making a comeback in modern farming routines.

By using trees and shrubs, agroforestry systems restore the benefits of forest plants to agricultural lands, increasing productivity and improving environmental services, such as erosional control, pest control, water management, and climate regulation. Agroforestry can increase farm profitability in several ways: (1) the total output per unit area of tree/ crop/livestock combinations is greater than any single component alone; (2) crops and livestock protected from the damaging effects of wind are more productive; and (3) new products add to the financial diversity and flexibility of the farming enterprise. Biodiversity in agroforestry systems is typically higher as they incorporate several plant species into a given land area and create a more complex habitat that can support a wider variety of birds, insects, and other animals. Agroforestry also has the potential to help reduce climate change since trees take up and store carbon at a faster rate than crop plants. The benefits of agroforestry add up to a substantial improvement of the economic and resource sustainability of agriculture.

How EcoLogic is using agroforestry

As an alternative to the slash-and-burn agricultural practices that are degrading eastern Guatemala, Ecologic and its partner in the region initiated the planting of guama (Inga edulis), a native tree species, alongside corn and beans. Every aspect of the guama plant promotes sustainable agriculture: its roots hold the earth in place, preventing erosion; its leaves shade the soil, helping it to retain moisture; its fallen leaves serve as organic fertilizer, rejuvenating the soil with nutrients; and its branches can be trimmed for firewood, reducing the need for further deforestation. Planting guama among crops is also incredibly economically viable: farmers save money on fertilizer and their crop yields increase by 50 percent. 

Agroforestry around the world

Alleycropping is the practice of planting rows of trees amidst other crops. (Photo credit: USDA NRCS.)

Agroforestry has been practiced since the early 1900s in the United States, including alleycropping, silvopasture, windbreaks or shelterbelts, riparian buffer strips, and forest farming or special forest products. Alleycropping involves growing crops (grains, forages, vegetables, etc.) between trees planted in rows. Tree and pasture combinations are called silvopastoral agroforestry. Windbreaks or shelterbelts involve planting trees in single or multiple rows along the edge of a field to reduce wind effects on crops or livestock. Trees, grasses, and/or shrubs planted in areas along streams or rivers are called riparian buffers or filter strips. When a natural forested area is managed for both wood products and an additional enterprise, it becomes an agroforestry system - forest farming or special forest products. For example, in 1987, approximately 858,000 windbreaks in the United States, mostly in the north central and Great Plains areas, spanned 281,000 km and protected 546,000 ha.

Agroforestry practices are also making great progress in other nations around the world. A study on the North China Plain revealed that agroforestry exhibits an advantage over mono-cropping in its natural ability to sequester carbon from the atmosphere at a yearly rate of about 1.23 x 106 tons of carbon. Also, paulownia-wheat intercropping systems with corn, beans and cotton suggest an average yearly income increase of $650.51. In the Canadian prairies, more than 43,000 km of windbreaks have been planted since 1937, protecting 700, 000 ha. In Southern Mexico, 400 small-scale farmers in 20 communities are converting from swidden agriculture to agroforestry. Agroforestry projects in Ghana from the late 1980s made the achievement of 119 demonstrations, 131 nurseries and 1,642 hectares of agroforestry by 1992.

However, agroforestry research and extension are not evenly developed around the world. For example, in Panama, agroforestry is relatively new. Before 1980 there was no formal research, and it was not until 1986 that the first development projects with an agroforestry component were identified.

Many other agroforestry projects are being implemented. The Agricultural Research Service in the United States advocates agroforestry techniques to small farmers in an economic bind, while the International Centre for Research in Agroforestry is aiding the African country of Malawi to engage in a major agroforestry initiative to help rejuvenate soils and battle severe food deficits. In Brazil, the Projecto Abraco Verde (Project Green Hug) is underway to provide training and assistance to formerly landless farmers, enabling them to reclaim fragile marginal forest lands that would otherwise be left for ecological death.

read about how EcoLogic is using agroforestry

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