Terracing
Worldwide Methods
In Africa a certain method called "fanya juu" comes from the Swahili phrase meaning "make it up." It began in Kenya during the 1950s, when standard Western practices could not control the fierce erosion in the area and also took too much arable land out of circulation. Fanya juu produces embankments by carving out ditches and depositing the soil uphill to form embankments. The ditches can be used to grow banana plants while another crop is planted on the embankments. A variation involving Western channel terracing is called "fanya chini," but this is less popular because the ditches must be desilted of churned-up topsoil on a regular basis. Additionally, in very steep areas only bench terracing can be truly effective.
Yemeni mountain land was once cultivated widely by farmers, but it made for a difficult living. So when oil became a bigger economy than agriculture in the surrounding countries, the farmers slowly migrated to places like Saudi Arabia in order to seek greater fortunes in a new business. The agroecosystem left behind began to slowly contribute to soil erosion, because the arrangement of bench terraces, small dams and irrigation or runoff conduits was decaying. By 1987, one researcher found that thin or shoestring rills were deepening into gullies on the mountainsides.
The benches of Lebanon, some of which have existed for over two and a half thousand years after being instituted by the Phoenicians, were threatened by the battles of civil conflict in the area. Farmers were driven away to safer and more convenient living conditions in cities or in other countries. An investigation in 1994 warned of long-term damage to untended terraced lands including an increased possibility of landslides, and the chance that the land may be rendered eventually unfarmable.
Resources
Books
Moldenhauer, et al., eds. Development of Conservation Farming on Hillslopes. The Soil and Water Conservation Society, 1991.
Turner, B.L. Once Beneath the Forest. Boulder, CO: Westview Press, 1983.
Periodicals
"Bench Terracing in the Kerinci Uplands of Sumatra." Journal of Soil & Water Conservation (September/October 1990).
"Rehabilitating the Ancient Terraced Lands of Lebanon." Journal of Soil & Water Conservation (March/April 1994).
"Terrace Channel Design and Evaluation." Transactions of the ASAE (September/October 1992).
Jennifer Kramer
Additional topics
Science EncyclopediaScience & Philosophy: Swim bladder (air bladder) to ThalliumTerracing - Modern Practices, Worldwide Methods