Soil Microorganisms in Cycling of Elements or Plant Nutrient
Soil microorganisms are the most important agents in the cycling / transformation of various elements (N, P, K, S, Iron etc.) in the biosphere; where the essential elements undergo cyclic alterations between the inorganic state as free elements in nature and the combined state in living organisms. Life on earth is dependent on the cycling of nutrient elements from their elemental states to inorganic compounds to organic compounds and back into their elemental states.
The microbes through the process of biochemical reactions convert / breakdown complex organic compounds into simple inorganic compounds and finally into their constituent elements. This process is known as "Mineralization".
Mineralization of organic carbon, nitrogen, phosphorus, sulphur and iron by soil microorganisms makes these elements available for reuse by plants. In the following paragraphs the cycling / transformations of some of the important elements are discussed.
The four most important cycles are mention below
Sulphur Cycle / Sulphur Transformation
Phosphorus Cycle / Transformation
Iron Cycle / Transformation