The soil is a natural resource, non renewable in the short term or very difficult to renew and expensive either to reclaim or to improve following erosion, physical degradation or chemical pollution. The increasing pressure on land and water resources, leading to degradation and pollution of those resources, and a reduced productive capacity calls for a system which can store detailed information on natural resources of all kinds in such a way that these data can be accessed, combined and analyzed from the point of view of potential use, in relation to food requirements, environmental impact and conservation. Such a system is a prerequisite for policy formulation, development planning at all levels, efficient use of both internal and external resources, and for implementation of development programmes.
In a typical case such a system would consist of:
(1) A computerised database containing all available information on topography, soils, climate, vegetation and land use. It should be complemented with compatible databases of socio-economic factors.
(2) Geographical Information System or GIS, which links each item of information to its precise geographical location, but which can display each type of information as a separate layer, or overlay.
(3) A set of crop yield models which can calculate the level of production which could be obtained from each and any combination of soil and climate in the region or country, at a number of different input levels or management systems.
(4) Various environmental impact models, which, for example, allow the calculation of rates of erosion for a given land unit, use, and production system.
Development of computerized natural resource inventory and land evaluation systems especially for use in developing countries has been carried out by FAO since the early nineteen-seventies, notably under the Agro-Ecological Zones programme. In 1987, the International Soil Reference and Information Centre (ISRIC), based in Wageningen, the Netherlands, undertook at the request of UNEP and in close cooperation with the ISSS, FAO and the Land Resources Research Centre in Canada, to develop a Methodology for a World Soils and Terrain Digital Database (SOTER).
This land resource information system was tested in three pilot areas involving five countries (Argentina, Brazil, Uruguay, USA and Canada), using local data and training national staff in operation. Though further up-grading and improvement will continue, this system can now be established as an almost routine operation which mainly involves the provision of equipment, and training.
Most developing countries are quite acutely aware of the need, and many are already attempting to establish computerised natural resource databases of one kind or another. Furthermore, all donors and aid agencies, particularly those such as the World Bank, which seek comprehensive solutions, will TIF become aware that such systems are an essential tool for development, and are also very cheap in comparative terms.
A long term commitment from these agencies is needed so that SOTER can rapidly provide the key soil and terrain attributes, which are needed to assess the potential productivity of the land, the status, risk and rate of soil degradation, to develop action to conserve or rehabilitate the land, and to improve our understanding in global change.