To B and not B2 – the Australian soil horizon system: history and review

Soil horizon designation plays a key role in the communication of information about soils – hence need for uniformity, consistency and clarity way soil horizons are defined designated. Since its establishment late 19th century, A-B-C schema has evolved with realisation that traditional concepts genesis embedded original system do not fit breadth current knowledge regarding development. Along more objective approach, there been progress toward harmonisation, considerable agreement between two major international systems: FAO USDA. Both use an A-E-B-C-R mineral horizons, coupled prescriptive alphabetic suffixes. This is now adopted almost universally Australia alone retained once widespread numerically designated first codified USA 1937. The A1-A2-A3-B1-B2-B3-C-D-R can therefore be regarded as ‘Australian system’. also unique it designates organic horizons. review summarises history critically appraises Australian system. It identifies ambiguity inconsistency definition allocation demonstrates notation convoluted complex. Pedology would benefit by aligning approaches including simpler set objectively master rationalised intergrade rigorous application improve both profile utility databases.