Abstract

The World Reference Base for Soil Resources began as the International Reference Base for Soil Classification (IRB), an initiative of FAO, UNESCO, UNEP and the ISSS in the early 80s, following the publication of the Soil Map of the World (FAO-UNESCO, 1971-1981). The aim of IRB was to device a framework through which existing soil classification systems could be correlated and ongoing soil classification work could be harmonized.

Over some 12 years IRB developed in parallel and similarly to the Revised Legend of the Soil Map of the World (FAO-UNESCO-ISRIC, 1988). It was therefore decided to bring the two efforts under one umbrella; the World Reference Base for Soil Resources (WRB) was born. The main objectives were to provide scientific background to the Revised Legend, and to develop an internationally acceptable framework for delineating soil resources through which national classifications can be correlated – the Reference Base character.

With this Reference Base character in mind, subsequently a draft WRB (ISSS-ISRIC-FAO, 1994) and first official WRB (ISSS-ISRIC-FAO, 1998) together with explanatory texts (Working Group RB, 1998a, 1998b) were issued. At the 16^th World Congress of Soil Science in Montpellier it was decided to have a six-year period for testing and soliciting comments. During this period it became apparent that there was keen interest in WRB, as demonstrated by translations in 15 languages, and the wide use of the Lecture Notes on the Major Soils of the World, based on WRB (Driessen et al., 2001).

During the six-year period it also became obvious that WRB was growing beyond being a reference base; several countries took WRB as base for their soil classification and used it for soil mapping. There was a call for standardization amongst the soil terminology and definitions used in various soil classifications. Moreover, more refinement was sought to better characterize the soil through its name. Proliferation took place in the number of qualifiers used at the second level of WRB, sometimes without obeying the rules specified. All this raises the question: are we Wittingly Reaching Babel with WRB?

The current revision of WRB has focused on the shortcomings of the first edition, the comments received over the years, redefining and renaming some of its Major Reference Groups (Alisols, Stagnosols to include Planosols), sequencing of the Key to the MRGs, incorporation of some of the latest knowledge on soils, in particular that on recent man-made soils in urban and mining areas (as Technosols), and more logical structuring of the lower-level classification into prefix and suffix qualifiers. The concept of soils to classify has been broadened to include sub-aqueous and subterranean soils.