Plants, Nutrients and Australian Soils

Low availability of nitrogen in poor soils, and the loss of nitrogen through volatilisation during fire, can be compensated for by the action of nitrogen-fixing microbes: bacteria, cyanobacteria and actinomycetes. These organisms can convert (reduce) atmospheric dinitrogen (N₂) to ammonium (NH₄⁺).

Some filamentous cyanobacteria commonly found free-living in soils and fresh water.