The International Committee on Spodosols: Deliberations and Rationale

Revisiting the definitions of the sombric horizon in soil taxonomy and world reference base for soil resources

“…In many cases diagnostic horizons result from field and laboratory characterization of hundreds of pedons and considerable discussion at international workshops. Examples of subsurface horizons receiving international input include the spodic horizon in Spodosols (Ahrens and Rourke, 2000), the oxic horizon in Oxisols (Buol and Eswaran, 1988), and a variety of diagnostic horizons present in Aridisols (Kimble and Nettleton, 1990). Diagnostic horizons are used at the highest levels in global soil taxonomic systems, such as Soil Taxonomy (ST;Soil Survey Staff, 1999), the IUSS Working Group WRB (2007), and the new Russian soil classification system (Shishov et al, 1997).…”

Sombric Horizon

“…In many cases, diagnostic horizons result from field and laboratory characterization of hundreds of pedons and considerable discussion at international workshops. Examples of subsurface horizons receiving international input include the spodic horizon in Spodosols (Ahrens and Rourke 2000), the oxic horizon in Oxisols (Buol and Eswaran 1988), and a variety of diagnostic horizons present in Aridisols (Kimble and Nettleton 1990). Diagnostic horizons are used at the highest levels in global soil taxonomic systems, such as Soil Taxonomy (ST; Soil Survey Staff 1999), the IUSS Working Group WRB (2007), and the Russian soil classification system (Shishov et al 1997).…”