In most developing countries, the socio-economic needs of rapidly increasing populations are the main driving force in the allocation of land resources to various kinds of uses, with food production as the primary land use. Heavy population pressure and the related increased competition from different types of land users have emphasized the need for more effective land-use planning and management. Rational and sustainable land use is an issue of great concern to governments and land users interested in preserving the land resources for the benefit of present and future populations.
Policy-makers and land users face two basic challenges: the need to reverse trends of land degradation in already-cultivated areas by improving conditions and re-establishing their level of fertility; and prevention of the degradation of land resources in new development areas through appropriate and just allocation and use of these resources to maintain productivity and minimize soil erosion. In both cases an integrated approach to planning and management of land resources is a key factor in a solution which will ensure that land is allocated to uses providing the greatest sustainable benefits. FAO has been promoting the integrated planning and management of land resources in cooperation with regional institutions, individual countries as well as land users.
Over the last two decades, FAO has developed and successfully applied the agro-ecological zones (AEZ) methodology and supporting software packages to analyse solutions to various problems of land resources for planning and management for sustainable agricultural development at regional, national and sub-national levels. The issues addressed include linking land-use outputs with other development goals in such areas as food production, food self sufficiency, cash crop requirements, issues of soil fertility constraints, soil erosion risks and land degradation.
FAO has been assisting various countries such as Mozambique, Kenya, Nigeria, Brazil, China, Bangladesh, Nepal and Grenada in learning, applying and adapting the methodology to local conditions. Several southeast Asian countries such as Thailand, Malaysia and the Philippines have carried out AEZ studies, mainly on their own initiative, which have produced useful applications and results. FAO has organized regional and national workshops in Asia, Africa, Latin America and the Caribbean to discuss AEZ applications and experiences in the various regions and countries. Continuous expansion and refinement of AEZ land resources appraisal procedures and, more recently, linkage to geographic information systems (GIS) have greatly enhanced the power of AEZ land resources databases to implement a wide range of land resources applications. This includes large multilayer databases, linked with various kinds of models, management and decision-support tools and improved interfaces in order to facilitate the use of the systems by non-specialist users. Several variants of the methodology have emerged as it has expanded and been adapted to local conditions. A rich AEZ documentation has been produced which includes numerous detailed technical reports, training materials and workshop proceedings.
Given the expansion of AEZ methods and applications at global, national, district and sub-district levels, a clear need emerged to develop both a terminology and a set of guidelines to relate the scale and scope of agricultural development issues to corresponding levels of resolution in the description of AEZ land resources and facilitate the understanding and use of the voluminous AEZ documentation. These guidelines are supposed to fill this gap. They are intended to guide land resources specialists, land-use planners and other users wishing to design and implement AEZ studies in understanding the essence of the AEZ approach: its concepts and methods, the sequence of activities involved and the tools used, its core and advanced applications. They are also intended to be training material for use in courses and workshops on agro-ecological land resources appraisal.
This publication was prepared under the supervision of Mr. J. Antoine of the Soil Resources, Management and Conservation Service (AGLS) of the Land and Water Development Division. It is the result of material compilation from various sources, but with a focus on the most advanced version of the AEZ methodology as applied in the recent Kenya country study. A first draft was prepared by Mr. J. Van Wambeke and circulated for comment. This draft was revised and expanded by Mr. D. Radcliffe. The publication has also benefitted from comments and inputs from other AGL staff, including Messrs R. Brinkman, L. Jansen, F. Nachtergaele, D. Sims and W. Sombroek.
The procedures described are intended as optional guidelines to assist people throughout the world but particularly in developing countries to improve their own evaluations of their land and water resources and their own decisions on their use. Users' records and annotated experiences with the contents of the guidelines, comments on their usefulness and applicability and suggestions for improvements will be welcome to enable a future re-issue to be upgraded in the light of experience. Comments and suggestions should be sent to: