Effectiveness of jatropha barriers as a soil and water conservation technology to rehabilitate gullies in northern Ethiopia

Excerpt

Jatropha (Jatropha curcas L.), a perennial oil-producing shrub, has been promoted in many parts of sub-Saharan Africa in recent years, with the aim of producing biofuels, developing rural areas, and providing alternative income opportunities (Francis et al. 2005). Researchers largely agree that jatropha is suited for rehabilitating degraded land, as it improves microbial activity, available nutrients, and water holding in soils (Wani et al. 2012). The basic pattern of its root structure is believed to control soil erosion (Achten et al. 2007), although in drylands limited water availability has negative effects on jatropha root growth and overall performance (Krishnamurthy et al. 2012). Nonetheless, only few studies investigate vegetative soil and water conservation technologies based on jatropha. Rare individual studies, such as the ones by Openshaw (2000) on hedges or by Kagamebga et al. (2011) on the half-moon technique in Burkina Faso, demonstrate that jatropha can, in different ways, successfully be used for soil and water conservation.

In the Ethiopian Highlands, land degradation is a major concern, and the control and rehabilitation of gullies pose a particular challenge. Efforts to conserve soil and water have been made for a long time and at a large scale (Dale 2010). However, farmers often…