Soil represents one of the largest C sinks on Earth and is significant in the global carbon cycle and, therefore, for climate change mitigation.
[6] Therefore, SOM/SOC dynamics and the capacity of soils to provide the ecosystem service of carbon sequestration through SOM management have received considerable attention.
[8] SOM can be divided into three genera: the living biomass of microbes, fresh and partially decomposed detritus, and humus.
Surface plant litter, i.e., fresh vegetal residue, is generally excluded from SOM.
Above detritivores, there are also herbivores that consume fresh vegetal matter, the residue of which then passes to the soil.
Some animals, like earthworms, termites, ants, and millipedes contribute to both vertical and horizontal translocation of organic matter.
Soil microbes decompose it through enzymatic biochemical processes, obtain the necessary energy from the same matter, and produce the mineral compounds that plant roots are apt to absorb.
The ranking, from fast to slow rates, is: The reactions that occur can be included in one of three genera: The mineral products are: As vegetal detritus decomposes, some microbially resistant compounds are let undecayed, including modified lignins, oils, fats, and waxes.