Organic matter as the plant and animal residues we incorporate into the soil. We see a pile of leaves, manure, or plant parts and think, "Wow! I'm adding a lot of organic matter to the soil. This stuff is actually organic material not organic matter. Organic material is anything that was alive and is now in or on the soil. For it to become organic matter it must be decomposed into humus. Humus is organic material that has been converted by microorganisms to a resistant state of decomposition. Organic material is unstable in the soil, changing form and mass readily as it decomposes. As much as 90 percent of it disappears quickly because of decomposition. Organic matter is stable in the soil. It has been decomposed until it is resistant to further decomposition. Usually, only about 5 percent of it mineralizes yearly. That rate increases if temperature, oxygen and moisture conditions become favorable for decomposition, which often occurs with excessive tillage. It is the stable organic matter that is analyzed in the soil test. Organic matter causes soil to clump and form soil aggregates, which improves soil structure. With better soil structure, permeability infiltration of water through the soil improves, in turn improving the soil's ability to take up and hold water.
Related journals of organic matter:
Journal of Biofertilizers & Biopesticides, Journal of Environmental & Analytical Toxicology, Journal of Pollution Effects & Control, Forest Research: Open Access, Journal of Biodiversity & Endangered Species, Journal of Biodiversity, Bioprospecting and Development