Possible role of soil microorganisms in aggregation in soils

In many soils, roots and fungal hyphae, especially those of vesicular arbuscular mycorrhizal (VAM) fungi, stabilize macroaggregates (>250 μm diameter); organic residues, bacteria, polysaccharides and inorganic materials stabilize microaggregates (<250 μm). This review discusses the factors (including other organisms) which affect VAM hyphae and their extracellular polysaccharides in soil, and the subsequent effect on stability of aggregates. The review also discusses the possible role of other organisms, including ectomycorrhizal fungi, in the stability of soil, and suggests future research.