World Soil and Terrain Database

The updating of world soil resources, using the Soil and Terrain (SOTER) digital database methodology, is part of a global SOTER programme and intended to replace the FAO/Unesco 1:5 million scale Soil Map of the World (1971-1981). The original map sheets were published in 1970-1980 and were compiled on basis of information and data available at that time. It is understandable that a substantial part does not reflect the present state of knowledge of the soils in the regions. The national institutes, responsible for the natural resources inventories, have been collecting a wealth of new information on the distribution and occurrence of soils in their region, which has resulted in updating their national soil maps mostly at scale 1:1 million, often applying the Revised Legend (FAO, UNEP, ISRIC, 1988) for the description of the mapping units. The International Union of Soil Science (IUSS) adopted an important change in the classification used for the map by introducing lower levels of subunits of the World Reference Base for Soil Resources (IUSS, FAO, ISRIC, 1998). This, together with the new soil data available at national level, justified such an update of the soil resources for the regional updates (South America and the Caribbean, Northeastern Africa, Southern Africa, East and Central Europe, North and Central Eurasia and Central Africa have been completed to date.