Mineralisation releases nutrients in soils are tide up in

Mineralization releases nutrients in soils that are tied up in Organic matter.
Mineralization is the phrase used to describe the process whereby organic forms of nitrogen (N) in the soil are converted to available forms of N. This process is driven by microorganisms present in the soil decomposing organic matter for their energy supply.
Soil organic matter (SOM) mineralization is an important process in which carbon (C) and nutrients are transformed into CO₂ and plant-available forms of nitrogen (N), phosphorus (P) and sulphur (S).