found: Dunster, J. Dict. of natural resource management, c1996(humus: in the narrow sense, humus is amorphous organic material (plant or animal) that has decayed beyond the point of recognition, and lies beneath the litter layer and above the mineral soil. A rich component of soil containing humic and fulvic acids, humus forms the main organic layer on the forest floor, but can also be found in water. In the broader sense, humus may refer to the whole forest floor and organic matter within the mineral soil.)
found: The dict. of forestry, c1998(humus: black or brown organic material of complex composition which is the end-product of microbial breakdown of plant and animal residues at the soil surface --synonym soil organic matter)
found: Merriam-Webster dictionary online, Oct. 26, 2020(humus: geology : a brown or black complex variable material resulting from partial decomposition of plant or animal matter and forming the organic portion of soil)
found: Britannica online, Oct. 26, 2020:Humus (Humus, nonliving, finely divided organic matter in soil, derived from microbial decomposition of plant and animal substances. Humus, which ranges in colour from brown to black, consists of about 60 percent carbon, 6 percent nitrogen, and smaller amounts of phosphorus and sulfur. As humus decomposes, its components are changed into forms usable by plants) Histosol (Histosol, one of the 12 soil orders in the U.S. Soil Taxonomy. Histosols are formed under waterlogged conditions typical of peat bogs, moors, and swamps. Under such conditions, the accumulated tissues of dead plants and animals and their decomposition products are preserved, resulting in soils of high organic content)
