Can a continuous growth of agriculture be achieved in the sub-Sahara region without inducing irreversible damage to the ecosystem? Until now, doubts have been expressed as to the actual capacity of the soils to sustain a desirable increase of production which can match the requirements of a fast-growing population. Thirty years of investigation and a renewed comprehensive interpretation of research data on soil fertility show that a sustainable agriculture growth could be a practical possibility in a savannah region.Can a continuous growth of agriculture be achieved in the sub-Sahara region without inducing irreversible damage to the ecosystem? Until now, doubts have been expressed as to the actual capacity of the soils to sustain a desirable increase of production which can match the requirements of a fast-growing population. Thirty years of investigation and a renewed comprehensive interpretation of research data on soil fertility show that a sustainable agriculture growth could be a practical possibility in a savannah region.General Introduction.- 1 Scope of the Study.- 1.1 Geography.- 1.2 Agricultural Conditions.- 1.3 Aims of the Study.- 1.4 Procedure.- 1.4.1 Sources of Information.- 1.5 Interpretation.- 1.6 From Scientific Analysis to Technical Advice: Extrapolation.- I Fertility and Agricultural Development.- 2 Definition of Fertility.- 2.1 Introduction.- 2.2 Components of Fertility.- 2.2.1 Climate and the Plant.- 2.2.2 Soil and the Plant.- 2.3 The General Concept of Fertility.- 2.3.1 Production Potential.- 2.3.2 Costs.- 2.3.3 The Risks.- 3 The Farming Environment.- 3.1 Climate.- 3.1.1 Drought.- 3.1.2 Consequences of Climate for Agriculture.- 3.2 Natural Vegetation.- 3.3 Soil Morphology and Pedology.- 3.3.1 Soils on Dune Sands.- 3.3.2 Soils on the Basement Complex and Continental Sediments.- 3.3.3 Possibilities for Cultivation.- 3.4 Physicochemical Properties of the Soils.- 3.4.1 The Organomineral Fraction.- 3.4.2 Surface Activity.- 4 Population and Migration.lă&