Why does soil organic matter matter?

Many soils around the world are under pressure from land-use change, erosion, pollution, and climate change. One common feature of degraded soils is the decline of soil organic matter (SOM).

SOM helps soil particles form stable aggregates, which improves soil structure and makes soils more resistant to erosion. It increases the soil's capacity to retain water, which can be crucial during dry periods. As organic matter decomposes, nutrients are released gradually and become available to plants.

SOM also provides energy and habitat for soil organisms. Bacteria, fungi, and soil animals use organic materials as food and transform them through decomposition. Even relatively small changes in SOM can influence how well soils support plant growth and environmental processes.