Describe the processes and products of decomposition.
The steps of decomposition are fragmentation, leaching, catabolism, humification, and mineralization.
a. Fragmentation: Detritivores like earthworms break down detritus into smaller fragments or particles.
b. Leaching: In this process, water-soluble inorganic nutrients percolate into the soil horizon and get precipitated as unavailable salts.
c. Catabolism: The bacterial and fungal enzymes degrade detritus into simpler inorganic substances. All of the above steps occur simultaneously.
d. Humification: It leads to the accumulation of a particularly decomposed, dark-coloured, amorphous, a colloidal organic substance called humus. Humus serves as a reservoir of nutrients. It is resistant to microbial action and undergoes decomposition at an extremely slow rate. Humus changes the soil texture and increases the capacity of water holding in the soil.
e. Mineralization: Some microorganisms degrade humus and release inorganic nutrients by the process of mineralization.