U.S. Soil Taxonomy

Except for the top soil where the colour caused by Fe oxides is often masked by hu-mics, most of the soil profile receives its brown, yellow or red colour from Fe oxides (Bigham Ciolkosz, 1993). Because this is so obvious to the naked eye, soils have been named according to colour in most national classification systems, e. g. red-yellow podzols (USA), sol ochreux (France), Braunerde (Germany), krasnozem (Russia), terra rossa (Italy), and even the current modern international systems (U.S. Soil Taxonomy system and World Reference Base for Soil Resources, WRB) use colour connotations such as Rhodic (red) and Xanthic (yellow). 

The Brazilian Latossolos correspond to well drained Oxisols in the U.S. Soil Taxonomy, and the FAO-UNESCO soil map legend identifies them as Ferralsols. In the French classification they are defined as Sols Ferrallitiques, commonly fortement d at-ures, typiques. The Podzolicos belong to the Alfisols (when eutrofic) and to the Kandisols... 

Brazilian Classification U.S. Soil Taxonomy Mean Median SD SE... 

Beinroth, F. H. 1975- Relationships between U.S. soil taxonomy, the Brazilian soil classification system, and FAO/UNESCO soil units. In Soil Management in Tropical America, eds. E. Bomemisza and A. Alvarado (North Carolina State Univ., Raleigh), pp. 92-108. 

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See also in sourсe #XX -- [ ]

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