Proposal for a new reference group for the World Reference Base for Soil Resources (WRB) 2006: the Technosols

This document proposes changes to the World Reference Base for Soil Resources (WRB) to better acommodate soils dominated by technic material. It is the second draft, aiming at the revision of the WRB to be submitted at the 2006 International Union of Soil Sciences (IUSS) meetings. Three new definitions are proposed: – Artifacts are defined as solid or liquid material created by humans as part of an industrial or artisanal manufacturing process and found in the soil. – Technic soil material is defined as material dominated by artifacts and having properties substantially different from those of natural soil materials, and recognizable as such in the soil. – Human-transported soil material is defined as material moved into a pedon from a source area outside of its immediate vincinity by intentional human activity, and recognizable as such in the soil. Technosols is proposed as a new reference group, whose central concept is soils whose properties and pedogenesis are dominated by technic material or their origin as human-transported material. It also includes pavements underlain by unconsolidated material, as well as soils with a continuous impermeable constructed liner. The Technosols are to follow the Histosols and Anthrosols in the key to reference groups. Organic soils which otherwise qualify as Technosols are excluded from the Histosols. Soils from technic materials which otherwise would qualify as Anthrosols are likewise excluded from the Anthrosols and classified as Technosols. A list of qualifiers for Technosols is proposed. The first priority group of prefix qualifiers indicates how the soil qualified as a Technosol in the key: Ekranic (pavements), Lined, Technic or Spolic. This also serves as a sub-division of the Technosols Other prefix qualifiers are intergrades in key order, including (among others) Histic, Anthric, Hyperskeletic, Fluvic, Vitric, Andic and Hyperarenic. Suffix qualifiers are proposed for other characteristics which influence soil behaviour or where pedogenetic horizons have developed. Technic and Spolic suffix qualifiers are proposed for other groups where there is insufficient technic or human-transported material to qualify as Technosols but enough to influence soil behaviour. Compactic and various -toxic phases for contaminated soils are proposed, applicable to all groups.