World Reference Base for Soil Resources

The World Reference Base for Soil Resources (WRB) is the international standard taxonomic soil classification system endorsed by the International Union of Soil Sciences (IUSS). It was developed by an international collaboration coordinated by the International Soil Reference and Information Centre (ISRIC) and sponsored by the IUSS and the FAO via its Land & Water Development division. It replaces the previous FAO soil classification.

The WRB borrows heavily from modern soil classification concepts, including USDA soil taxonomy, the legend for the FAO Soil Map of the World 1988, the Référentiel Pédologique and Russian concepts. The classification is based mainly on soil morphology as an expression pedogenesis. A major difference with USDA soil taxonomy is that soil climate is not part of the system, except insofar as climate influences soil profile characteristics. As far as possible, diagnostic criteria match those of existing systems, so that correlation with national and previous international systems is as straightforward as possible.

The WRB is meant for correlation of national and local systems. The level of detail corresponds to USDA soil taxonomy subgroups, without the soil climate information. It is not detailed enough for mapping at scales larger than about 1:200k, although proposal have been made to couple WRB with substrate information to map at 1:50k in regional studies.

WRB 98 soil groups

References

* Bridges, E. M. (1997). World soils (3rd ed.). Cambridge: Cambridge University Press.
* Bridges, E. M., Batjes, N. H., & Nachtergaele, F. O. (Eds.). (1998). World Reference Base for soil resources : atlas. Leuven: ACCO.
* Deckers, J. A., Nachtergaele, F. O., & Spaargaren, O. C. (Eds.). (1998). World Reference Base for soil resources : introduction. Leuven: ACCO.
* Driessen, P., Deckers, J., Spaargaren, O., & Nachtergaele, F. (Eds.). (2001). Lecture notes on the major soils of the world. Rome: FAO.
* FAO. (1998). World Reference Base for Soil Resources. Rome: Food and Agriculture Organization of the United Nations.
* Jahn, R., Joisten, H., & Kabala, C. (2004). The “Reference Soil Series” Concept of the First European Joint Soil Map at a Scale of 1:50 000, Sheet Zittau – a Framework to Upgrade the Information Content of Lower Level WRB Units. Paper presented at the EUROSOIL 2004, Freiburg im Breisgau (D).

External links

* [http://www.fao.org/ag/agl/agll/wrb/default.stm WRB home page at the FAO]
* [http://www.fao.org/ag/agl/agll/wrb/doc/wrb2006final.pdf WRB keys (pdf file)]
* [http://www.itc.nl/personal/rossiter/research/rsrch_ss_class.html#WRB WRB links at the Compendium of On-line Soil Survey Information]