Current projections on increasing population pressure and food production requirements in the next few decades show the urgent need for a world inventory of existing soil resources, and a realistic evaluation of their potential for agricultural production.
Huge areas in the humid tropics of Africa and South America are sparsely populated and offer sizeable possibilities for the expansion of agricultural areas. Climate and topography are highly suitable for vegetal growth but the prevailing soils are strongly weathered and require careful management. These soils formerly known as Latosols or lateritic soils are now classified as Oxisols (USDA, Soil Taxonomy), sols ferralitiques (French classification) or Ferralsols (FAO/Unesco Soil Map of the World).
As a result of their low fertility, shifting cultivation is at present the most widespread type of utilization of these soils. It includes long periods of fallow during which the soil organic matter and nutrient reserves, depleted after a few years of annual cropping, are reconstituted.
Under primitive agriculture and low population density, allowing for long fallow periods, shifting cultivation in humid tropics does not cause any major soil degradation. However, such low intensity type of utilization does not lend itself to accelerated agricultural development and in the areas where the fallow period has been progressively shortened due to population pressure, accelerated soil depletion and degradation are widespread.
It is also a general experience that intensive annual cropping and mechanized agriculture, as practised under temperate climates, may lead in a few years to serious degradation of Ferralsols, unless the cultural practices are carefully adapted to their delicate nutrient balance and the conditions of the tropical environment. With good management practices, however, high yields of both food and industrial crops can be obtained. Such potential for sustained production has been demonstrated in experiment stations, agricultural development projects and industrial plantations.
The purpose of the present Bulletin is to compile the information available on Ferralsols, their properties, the experience accumulated on their management and their production potential for intensive agriculture. It is hoped that this publication will contribute to a better knowledge of one of the most widespread soils on the earth, and to their optimum utilization and conservation.
This is a retyping of the original bulletin produced in 1974
