Steps of decomposition

During the decomposition process of organic matter, the following five steps occur simultaneously.

1. Fragmentation

• This process is initiated by detritivores. It is the first stage of decomposition. Fragmentation means the breakdown of the large piece (detritus) into smaller pieces.

2. Leaching 

• Fragmented particles may contain water-soluble nutrients. The nature of these nutrients is inorganic. These nutrients get dissolved in water and seep into the soil.

3. Catabolism 

• When the complex or large compound changes into smaller particles and the inorganic nutrient are removed, the enzyme is released by the decomposer. These enzymes convert or break down detritus into the simpler inorganic compound.

4. Humification

• It is the process of formation of humus. Humus is a dark-colored, highly nutrient-rich layer on the soil. This layer is made up of amorphous substances which are highly resistant to any action of the microorganism. Humus provides high fertility to the soil.

5. Mineralization

• The conversion of organic matter into inorganic compounds or minerals is called mineralization. Some of the minerals like NO₃^–, PO₄^3-, etc., are important plant nutrients. Besides these, CO₂, H₂O, Ca⁺, NH₄⁺, SO₄^2- etc., are generated and released into soil during mineralization.