If these processes are disrupted, human health can ultimately be harmed. Not all topics addressed pertain directly to agriculture, but the overall treatment may help in understanding issues of soil health and regeneration. The Cast of Characters Soil microbial communities are typically diverse. In addition, the roles of the various species are inextricably interconnected, so that, in experiments, direct and indirect treatment effects may be indistinguishable. This article considers mainly the bacteria and fungi.
Soil bacteria are mostly saprophytes or parasites.
Even motile bacterial types, however, can occur in colonies in the soil, and this habit may confer advantages such as improved nutrient mobilization and absorption, and protection from drying, toxins, or ultraviolet radiation. The filamentous habit also enables exploration of large soil volumes, provides protection against being washed through the soil profile, and permits specialization of cells to fulfill various functions more efficiently. ATP can be generated by fermentation or respiration. These processes, important in nutrient cycling and in detoxification of soils, can only occur in the presence of oxygen. The pH of the soil solution is another factor that governs enzymatic activity.