The phenomenon is most pronounced in the dryland, which cover more than 40% of the earth's surface (Dobie, 2001). Around 73% of rangelands in dryland areas are currently degraded, together with 47% of marginal rain fed croplands and a significant percentage of irrigated croplands (UNCCD Agenda 21, 1992; UNCCD, 1994). Overgrazing has damaged about 20% of the world's pastures and rangelands (FAO, 1996).
The degradation of land may be the result of numerous factors or a combination thereof, including anthropogenic (human related) activities such as unsustainable land management practices and climatic variations. Note that degradation processes e.g. erosion do occur naturally, and are generally balanced by the rate of soil formation. However, accelerated degradation is typically associated with human modification of the environment. The underlying causative factors of land degradation and environment are poverty and undervaluing of natural resources. In both cases people focus on immediate economic gain irrespective of damage to the same resources they are dependent on. The latter in particular promotes inefficient use and wastage of resources.
The cycle of processes leading to and perpetuating land degradation
(Source : FAO)
Land degradation, resulting from unsustainable land management practices, is a threat to the environment as well as to livelihoods, where the majority of people directly depend on agricultural production. There is a potentially devasting downward spiral of overexploitation and degradation, enhanced by the negative impacts of climate change leading in turn to reduce availability of natural resources and declining productivity : this jeopardizes food security and increases poverty. Sustainable land and Ecosystem management (SLEM) project is rooted in the rational that food security through enhanced agricultural productivity can be achieved through sustainable management of the country's natural and agro ecosystem.