Term (Latin for earth) for the totality of almost exclusively dead organic matter soil, which makes up the vast majority of soil organic matter (OBS or SOM = Soil Organic Matter). Around 5% of the OBS also consists of living organic matter, i.e. all living animal (such as woodlice, mites, caterpillars, earthworms, snails and spiders) and vegetable (such as among others) seaweed, Lichens and mosses) organisms, as well microorganisms (Bacteria, fungi). A teaspoon of humus contains 100 million bacteria, 60 kilometers of fungal threads and 1,000 thread worms. The living part of the OBS is also called Edaphon (grch. Edaphos = earth).
The humus is primarily subject to the active activity of the living soil organisms, which continuously contribute to the transformation (humification) through their metabolic activities. A distinction is made between a relatively small proportion of as yet unconverted substance protein and carbohydrates, as well as the predominantly dark colored part of organic compounds, the humic substances. In common usage, both are collectively referred to as humus. Strictly speaking, this only means the already converted organic part. The levels of humification are fluent and therefore an exact delimitation is not possible.
Starting materials for humus formation are plant residues from dead vegetation, fallen leaves, harvest residues, grapes from the thin out, dead root parts, dead microorganisms, excretions of soil animals and green manure (Short-term greening), as well as the supply of organic material such as manure, liquid manure, liquid manure, compost. mulch, Rebholz, manure and rape for the purpose of fertilization, It is only through humification that the organic material becomes a number of nutrients like most of all nitrogen, but also potassium. phosphorus and others released in plant-available form.
In the Weingartenboden, humus is particularly advantageous in the top layer, the A horizon (see also under soil type ). It improves heatability and thus activates soil life. Humus can weigh up to five times its own weight water save, so that the Water storage capacity is improved. It also increases the risk of leaching out for various nutrients such as potassium. calcium and magnesium reduced. See also under Weingarten Care,