What is "soil organic matter" made up of?

Soil organic matter is primarily composed of decomposed plant and animal material. This organic matter includes a complex mixture of decomposed residues such as leaves, roots, and other plant materials, as well as animal remains and byproducts from various microbial activity. It plays a vital role in soil health, influencing its structure, nutrient availability, and water retention capabilities.

The incorporation of decomposed materials contributes to the formation of stable organic compounds, which enhance the soil's capacity to support plant growth. Moreover, soil organic matter is essential for fostering beneficial microbial populations, nurturing soil biodiversity, and improving soil tilth.

While mineral particles, air, and water are important components of soil, they do not constitute organic matter itself. Living organisms, including microorganisms and earthworms, contribute to the decomposition process but are not included in the definition of soil organic matter, which strictly refers to the end products from decomposed plant and animal materials. Therefore, the response encompassing decomposed plant and animal material accurately defines what soil organic matter consists of.