Extensive grazing is the predominant form of land use on at least a quarter of the world’s land surface, in which livestock are raised on food that comes mainly from rangelands. Extensive grazing differs from crop or forestry production, in which the produce remains in situ whilst growing. Evaluation for extensive grazing, unlike that for cropping or forestry, must take into account the production of both grazing forage, termed primary production, and the livestock that feed on this forage, termed secondary production.

The project was first conceived as a “Transnational project on the Management of Major Regional Aquifer in N.E. Africa” during the UNCOD held in Nairobi in 1977 and that it had been taken up by ADALCO in 1987. He pointed out that the sandstone aquifer occupying an area of about 2,000,0000 sq. km underlines the common border areas of Sudan, Egypt, Libya and Chad. Environmentally, it was observed that the zone has a relief characterized by a vast sandy plan, which is occasionally interrupted by scattered flat topped Nubaian plateaux and escarpments.

Most of our semi-arid land is threatened with increased land deterioration due to
changes in land use especially in areas where soils have sealing properties which
hinder infiltration of rain- water. The study was carried out in Kibwezi Division,
Machakos District, a distance of 220 km. from Nairobi. It was designed to investigate
major causes of land deterioration following human settlement around 1963 and low
cost measures of reversing it.
The experiment was designed to investigate whether slashing bush and spreading

This article suggests that communual rangeland management policies in Botswana and Zimbabwe are based on incorrect technical assumptions about the stability of semiarid rangelands, the nature of rangeland degradation, and the benefits of destocking. Consequently, inappropriate policies, stressing the need to destock and stabilise the rangelands, are pursued.Acknowledgement of the great instability but intrinsic resilience of rangeland would encourage the Governments to more favourable regard the opportunistic stocking strategies of the agro-pastoralists of the Communual Areas.

The recent FAO in-depth study on agricultural and food problems in Africa concluded that even the present inadequate food supply situation is unsustainable. Unless major policy decisions are taken and implemented to resolve the food production crisis and reduce the rate of population growth, the trends of the past 25 years will continue and the food supply situation will continue to deteriorate during the next 25 years. Famine of the magnitude experienced during the 1983-1934 drought could become a regular feature even in period of more average rainfall.

The expert group meeting was held in the spirit of the Lagos Plan of Action,particularly chapters I and IX dealing with Food and Agriculture,UNEP Governing Council decision SC.11/7 of may 1983 on the program budget for 1984, part eight on the Regional Program for Africa, dealing with, inter alias, the prevention of

post harvest food losses and encroachment on arable land. The objective of the meeting was to review on-going activities and identify gaps where future activities should he directed.

Shifting cultivation, under its diverse forms of slash and burn system, is a traditional method of cultivating tropical upland soils, mostly for subsistence purposes. This traditional system of cultivation is in ecological balance with the environment and does not irreversibly degrade the soil resource, provided a sufficient length of fallow is allowed for soil restoration. However, increasing population pressures necessitate more intensive use of land. The consequence is extended cropping periods and shortened fallows.

This publication has been prepared as a background paper in view of the UN conference on the human environment that was held in Stockholm in 1972. This background document had contribution from UNESCO, IAEA and WHO. While the demand for land for land increases at a very rapid rate through population growth, technological progress and industrial development, soil resources remain fixed. The maintenance of their productivity is therefore of paramount importance.

LADA (Land Degradation Assessment in Drylands project) is a scientifically-based approach to assessing and mapping land degradation at different spatial scales ? small to large ? and at various levels ? local to global. It was initiated in drylands, but the methods and tools have been developed so as to be widely applicable in other ecosystems and diverse contexts with minimal required adaptation.

The WOCAT-LADA-DESIRE mapping tool is based on the original WOCAT mapping questionnaire (WOCAT, 2007). It has been expanded to pay more attention to issues such as biological and water degradation, it also places more emphasis on direct and socio-economic causes of these phenomena, including their impacts on ecosystem services. It evaluates what type of land degradation is actually happening where and why and what is being done about it in terms of sustainable land management (SLM) in the form of a questionnaire.

The objective of the Land Degradation Assessment in Drylands (LADA) project was to develop tools and methods to assess and quantify the nature, extent, severity and impacts of land degradation on dryland ecosystems, watersheds and river basins, carbon storage and biological diversity at a range of spatial and temporal scales. This builds the national, regional and international capacity to