Ammonification

Decaying waste, such as decomposing organisms and manure, are full of organic nitrogen. Through mineralization, this organic material is broken down into inorganic compounds by decomposers, such as fungi and bacteria.

Ammonification is a particular kind of mineralization involved in the nitrogen cycle. In this process nitrogenous organic matter, such as nucleic acids and amino acids, are converted to ammonia.

Organic matter → NH₃
As plants and animals produce waste or die they form organic matter, which is broken down by decomposers. This process releases nitrogenous compounds, such as ammonia, back into the environment.
Figure 1: An overview of ammonification

Referred from:

Article

The Nitrogen Cycle