ABSTRACT
Though ancient farmers and agriculturists recognized the diversity and differential quality f their soils by giving them names. Soil classification—except for taxation purposes—was developed only at the end of 19th century, following the Dokuchaev and followers recognition of soil profiles as specific natural bodies. National or local soil classification systems were commonly used when mapping soil resources. Only the hierarchical six-levels USDA Soil Taxonomy, which promotes quantitative limits with the concept of diagnostic horizons, and the ISSS (now IUSS) sponsored two-tier and less comprehensive World Reference Base for Soil Resources (WRB) can claim expanding worldwide use.
