New Terms for Describing Human-altered and Transported Soils.
John M. Galbraith, Virginia Tech, Dept. of Crop & Soil Env. Sci., 239 Smyth Hall (0404), Blacksburg, VA 24061 and Craig Ditzler, USDA-NRCS-NSSC, 100 Centennial Mall North, Room 152, Lincoln, NE 68508-3866.
Soils that have been profoundly altered by humans are pervasive in urban, suburban, industrial, and intensely farmed agricultural areas. Human-altered soils have been described using a variety of terms borrowed from other disciplines or from classification systems used to describe agricultural soils. New terms are needed to consistently describe and sample profoundly-modified or transported soils and the manufactured features and objects they contain. New terms have been proposed in ICOMANTH circular letter 6 for human transported materials, manufactured layers, anthropogenic features, and artifacts. Artifacts are broken down into subcategories that include: human-safety (innocuous versus noxious), size, and general types; and degree of cementation, potential subsidence, and excavation difficulty (where needed). In order to allow full description of uncontaminated (innocuous) soils, new terms are proposed for the USDA-NRCS National Soil Survey Handbook for describing artifacts and paraartifacts as fragments; artifactual material and manufactured layer are new terms used in lieu of texture; and artifactual, very artifactual, and extremely artifactual are used as new texture modifiers. For naming soil horizons, the “star” symbol ( * ) will be used as a prefix to identify horizons and layers of human-transported material; the new master horizon M will be used to describe manufactured layers; and the lowercase letter “u” is used to identify horizons or layers that contain an observable amount of artifacts or anthropogenic features. Contaminated (noxious) soils can also be remotely described using the new terms but should not be sampled or analyzed except by highly-trained experts.