This publication reports on a study of the increase in river salinity and the implemented control programs in five major irrigated basins in the arid zone. The study is limited to salinity.

Published in ?Tropical Medicine and International Health, Vol.6, No.1, pp.46-54, January 2001.? The complete article is available on the CD-ROM version of this Annual Report.

Discusses the historical context of ILCA's research, the principal types of animal production systems and the stages in ILCA's farming systems research. Describes the smallholder farming in the Ethiopian highlands & humid zone, the agropastoralists of the sub-humid zone, systems research in pastoral areas of eastern Africa (Kenya & Ethiopia), characteristics of the arid and semi-arid zones of West Africa and the role of modelling in the system. Ends with a summary of past experience.