horizon O

CONT: Horizon O. [...] C'est l'horizon organique dans lequel les débris végétaux sont partiellement décomposés et pratiquement non reconnaissables sur le terrain. Il contient 30 % de matière organique.

CONT: The O horizon, is comprised of accrued litter — leaves, twigs, peat soil and organic materials. This is called the O (for organic) horizon. The O horizon has no mineral materials. The deepest part of the O horizon may have organic soils, but they are mostly composed of forest litter and muck.