One of the layers that form in the soil
profile as a result of soil-forming
processes.
A horizon can appear as a defined visible layer. Single layer in soil
profile with similar properties or material but which differs at least in one property, e.g. colour or
texture from adjacent horizons above or below in the
profile; diagnostic horizon: Dominant soil property or material defines name of horizon, e.g. gypsic horizon having distinct calcium sulfate (gypsum: CaSO4) enrichment; genetic horizon depending on the type of
pedogenesis.