Understanding the observed effects of dung beetles and dung decomposition on plant productivity requires knowledge of the role of organic matter in the soil. In addition, SOM stabilizes soil structure, buffers soil pH, and aerates the soil.
Plant growth is highly dependent upon organic matter.
Mineralization of SOM by bacteria provides a source for N, P and S for plants. The amount of N 2 fixed by bacteria is dependent upon the amount of organic matter in the soil, as N-fixing bacteria require organic matter as an energy source. Soils poor in SOM suffer from reduced water infiltration, increased runoff and erosion, and soil compaction. Any of these factors can lead to reduced productivity. Other negative effects are increased sedimentation and siltation of reservoirs and coastal areas, eutrophication of rivers and lakes, and decreases in above- and belowground biodiversity.