This audiotutorial unit (cassette, printed script, 76 color slides, study guide, self-evaluation test), prepared by the Communications Support Unit at CIAT, is available for use with a manually or automatically synchronized slide projector/cassette tape reccorder. Each unit is a vailabIe from the Distribution Office at a cost of US$ 50; photocopies of the study guide alone can be obtained from the Cassava Information Center. The objective of this unit is to present some of the results of research conducted by the physiology Section of CIATs Cassava Program.

Conservation agriculture (CA) is increasingly promoted in Africa as an alternative for coping with the need to increase food production on the basis of more sustainable farming practices. Success with adopting CA on farms in Africa has been limited, despite more than two decades of research and development investments. Through analyzing past and on-going CA experiences in a set of case studies, this paper seeks to better understand the reasons for the limited adoption of CA and to assess where, when and for whom CA works best.

Improved understandings of the agricultural and range ecologies of semi-arid Africa require better information on the spatiotemporal distribution of domestic livestock across agropastoral landscapes. An empirical GIS-based approach was developed for estimating distributions of herded livestock across three agropastoral territories (around 100 km2 each) over a two-year period.

Intergovernmental Panel on Climate Change (IPCC) Tier 1 methodologies commonly underpin project-scale carbon accounting for changes in land use and management and are used in frameworks for Life Cycle Assessment and carbon footprinting of food and energy crops. These methodologies were intended for use at large spatial scales. This can introduce error in predictions at finer spatial scales. There is an urgent need for development and implementation of higher tier methodologies that can be applied at fine spatial scales (e.g.

Several traditional methods of maintaining soil fertility in bean-based cropping systems are reviewed as follows: visoso, large- scale chitemene, ngoro or matengo pit (Mbinga District, Tanzania), mambwe land-use system of northern Zambia (fundikila), mounds of the Wafipas (SW Tanzania), tumba land-use system (southern Tanzania), guie (central highlands of Ethiopia), mafuku in Zaire, termite mounds, agroforestry, relay intercropping systems, coffee- banana-bean cropping system of the Wahayas of Bukoba (Tanzania), removal of maize tassels (northern Malawi), and storage of nutrients in weeds (

Livestock systems globally are changing rapidly in response to human population growth, urbanization, and growing incomes. This paper discusses the linkages between burgeoning demand for livestock products, growth in livestock production, and the impacts this may have on natural resources, and how these may both affect and be affected by climate change in the coming decades. Water and land scarcity will increasingly have the potential to constrain food production growth, with adverse impacts on food security and human well-being.