_:b1217739 "FAO:http://fao.org/ag/agl/agll/wrb/doc/wrb2006final.pdf"^^ . _:b1217739 "Podzols are soils with a typically ash-grey upper subsurface horizon, bleached by loss of organic matter and iron oxides, on top of a dark accumulation horizon with brown, reddish or black illuviated humus and/or reddish Fe compounds. Podzols occur in humid areas in the boreal and temperate zones and locally also in the tropics."^^ . _:b1217739 . _:b1217739 . _:b1217739 .