ABSTRACT
Classification ƒ In the US Soil Taxonomy, the brown soils are Inceptisols and soils enriched with clay in the B are Alfisols, characterized by an argillic horizon. But even if a soil that has an argillic horizon is, by priority, classified in the Alfisols, it may also be a Mollisol, Spodosol (surface podzolization) or Ultisol (highly degraded soil). For example, Argi-udolls do exist. The WRB distinguishes Cambisols and Luvisols, the latter having an argic horizon (Table 8.2). Other than in Luvisols and Albeluvisols, the argic horizon may also occur in rarer soils that are not discussed here: Gypsisols, Alisols, Acrisols or Lixisols. Planosols are not affected by the argic horizon because they do not have a B with signs of clay translocation. Nevertheless, in the field there is a great family likeness between Albeluvisols and Planosols, so much so that investigators hesitate to choose between the two terms.
