Land Resources
Soil Legacy MapsHarmonized World Soil Database

World Reference Base



The World Reference Base (WRB) was originally an initiative of FAO and UNESCO, supported by UNEP and the International Society of Soil Science which dates back to 1980. The intention of the project was to work towards the establishment of a framework through which ongoing soil classification could be harmonized. The final objective was to reach international agreement on the major soil groups to be recognized at a global scale as well as on the criteria and methodology to be applied for defining and separating them.

Such an agreement was meant to facilitate the exchange of information and experience, to provide a common scientific language, to strengthen the applications of soil science and to enhance the communication with other disciplines. Several meetings of the ISSS subgroup were held starting in 1982 in New Delhi. In 1992, in Montpellier, France, it was decided that there was no justification to develop a completely new classification system very different from the Revised Legend published by FAO in 1988. Therefore the FAO Revised Legend was to be adopted as the Framework for WRB’s future work and that it would be the task of the working group to further develop its definitions and linkages to the existing FAO units, in order to give them more depth and validity.

The first draft version of WRB was presented at the 15th World Congress of Soil Science at Acapulco, Mexico, and since then it has been subjected to testing on consistency during meetings in Germany (1995), Russia (1996), South Africa (1996), and Argentina (1997). In November 1997, the last meeting was held in Vienna, Austria, and a final text was adopted which was consequently presented at the World Congress of Soil Science in Montpellier, France in August 1998. The first official WRB publication contained several volumes:

  1. World Reference Base for Soil Resources: Introduction (Working Group RB,1998a);

  2. World Reference Base for Soil Resources: Atlas (Working Group RB, 1998b);

  3. World Reference Base for Soil Resources (FAO/ISRIC/ISSS, 1998). 

The second edition was published in 2006 and launched at the 18th World Congress of soil Sciences at Philadelphia, USA. World reference base for soil resources 2006. A framework for international classification, correlation and communication. (IUSS Working Group WRB. 2006. World Soil Resources Reports No. 103. FAO, Rome).

The latest revised version is available from this website. Please click here.

In 2010, Guidelines for constructing small-scale map legends using the WRB were published.

All these publications carry the logos of the three main organizations involved in its development: The International Society for Soil Science (ISSS) which since 1998 is the International Union of Soil Science (IUSS), The International Soil Reference and Information Centre (ISRIC) and the Food and Agriculture Organization of the United Nations (FAO).

WRB officers 2010 - 2014
Chair: Peter Schad, Germany, schad<at>wzw.tum.de
Vice-Chair: Cornie Van Huyssteen, South Africa, vhuystc<at>ufs.ac.za
Secretary: Erika Micheli, Hungary, micheli.erika<at>mkk.szie.hu
Past Chair: Otto Spaargaren, The Netherlands, worldreferencebase <at> gmail.com