Agroforestry

Agroforestry systems have been historically significant as sources of food and fuel for forest-dependent and rural communities in Latin America, Sub-Saharan Africa and Southeast Asia. Agriculturalists that rely on such systems make the most efficient use of limited land. Agroforestry systems take a variety of forms. Many involve the intercropping of trees and crops. Trees would occupy the highest layer, with lower layers of shrub crops or annual grains, and a ground cover of species like squash. Agroforestry can be incorporated with livestock grazing rotations, such as silvopastoral systems in Northern Africa, where herders graze their livestock in dry forest, woodland, or wooded savanna. Agroforestry systems also provide a range of non-timber forest products (NTFPs) such as food, honey, medicine, as well as religious or spiritual significance. Other uses for agroforestry include structural adaptations such as living fences or windbreaks for both large scale agriculture and home gardens. 

Studies have shown that agroforestry techniques have a range of benefits, such as improving soil quality over time. The planting of legumes, particular pruning methods, and accumulation of leaf litter contributes to nutrient cycling that allows different species to occupy the same habitat. Alley cropping of mixed coffee and cacao crops and lower storey crops, annuals or perennials, where trees are planted to provide nutrients for those crops is a common example of agroforestry in Latin America. These cycling processes reduce the need for chemical fertilizers to sustain productivity of the trees and crops. Agroforestry systems have the added benefit of providing habitat, or physical structures for diverse range of species, aiding to increase local biodiversity.  

Other ecosystem services of agroforestry include improved air and water quality. Forests can act as windbreaks, protecting crops and wildlife habitat, and reducing erosion. Mixed tree and crop planting systems can act as riparian buffers, reducing the rate of agricultural surface runoff, in turn increasing infiltration, sediment deposition and nutrient retention. Agroforestry systems also contribute to carbon sequestration through the prevention of soil erosion and preservation of tree biomass. The amount of carbon sequestered relies on the type of species, species composition, climatological and geographic factors, and management methods, so the impact of agroforestry systems varies.  

Depending on the local context, sustainable harvesting of forest products can help maintain standing forest stock, while improving people’s livelihoods and food security. These changes can have a cumulative impact at the landscape scale, as agroforestry helps to retain forest cover by reducing the land area needed for crop cultivation, and allowing for multifunctional land use patterns. By providing communities with a means of subsistence and income generation, agroforestry can encourage the conservation of forests and restoration of degraded forestland

Given these effects, with the proper techniques, agroforestry can be a sustainable means of generating income and subsistence and an effective means of reducing emissions from deforestation and land degradation. However, with increased access to markets, communities engaging in agroforestry will need adequate incentives to avoid clearing forestland for conventional agriculture, which may be more profitable in the short term. Variations in agroforestry systems, ranging from forest farms to silvopastures or intercropped fields, should be taken into account when working with local communities’ needs. Read through to learn more about agroforestry systems in the Amazon Basin and the Congo Basin

 


Sources: 

Albrecht, A., & Kandji, S. T. (2003). Carbon sequestration in tropical agroforestry systems. Agriculture, Ecosystems & Environment, 99(1), 15-27. 

Jose, S. (2009). Agroforestry for ecosystem services and environmental benefits: An overview. Agroforestry Systems, 76(1), 1-10. 

King, K. F. S. (1987). The history of agroforestry. In Steppler, H. A., & Nair, P. R. (Eds.), Agroforestry: A decade of development (3-12). International Council for Research in Agroforestry (ICRAF). 

Montagnini, Florencia, and P. K. R. Nair. Carbon sequestration: an underexploited environmental benefit of agroforestry systems. Agroforestry Systems 61.1-3 (2004): 281-295. 

Nair, P. R. (1985). Classification of agroforestry systems. Agroforestry Systems, 3(2), 97-128. 

Palm, C. A. (1995). Contribution of agroforestry trees to nutrient requirements of intercropped plants. Agroforestry Systems, 30(1-2), 105-124.  

Rao, M. R., Nair, P. K. R., & Ong, C. K. (1997). Biophysical interactions in tropical agroforestry systems. Agroforestry Systems, 38(1-3), 3-50. 

Sanchez, P. A. (1995). Science in agroforestryAgroforestry Systems, 30(1-2), 5-55. 

Singh, G. B. (1987). Agroforestry in the Indian subcontinent: past, present and future. In Steppler, H. A., & Nair, P. R. (Eds.), Agroforestry: a decade of development (117-140). International Council for Research in Agroforestry (ICRAF).