What is the primary function of soil organic matter?

The primary function of soil organic matter is to enhance nutrient availability and improve soil structure. Organic matter is composed of decomposed plant and animal materials, and it plays a crucial role in both the chemical and physical properties of the soil. It serves as a reservoir for nutrients, making them more accessible to plants; this occurs because organic matter can hold onto nutrients in a form that is readily available for plant uptake. Additionally, organic matter contributes to improved soil structure, which enhances aeration, water infiltration, and root development. When soil structure is improved, it leads to better water retention during dry periods and improved drainage during wet periods.

While there are other important aspects of soil organic matter, like its ability to aid in filtering water, influence soil color, or provide some stabilization against erosion, these are not its primary functions. The enhancement of nutrient availability and structural improvement is foundational in supporting healthy plant growth and maintaining overall soil health.