Where organic matter and aluminium compounds dominate under either semiaquic or aquic conditions. Subsoil horizons that are humic are notated as a Bh Horizon. This term is used as a Great Group definition for the Podosol Order in the Australian Soil Classification ( Isbell, 1996). HUMOSE: The relatively resistant, usually dark brown to black fraction of soil organic matter, peat or compost which forms as a result of biological decomposition of organic material. Humose horizon (0-50 cm depth) of a Kurosol in the Corangamite region.