It is the process of breaking down of dead organic matter into smaller organic. molecules and inorganic molecules by Decomposers (bacteria, fungi)
- DETRITUS: Dead remains of plants and animals is called detritus.
- DETRITIVORES: Animals that feed on decaying organic matter (detritus). Examples: earthworms, termites, snails etc
Fragmentation of Detritus: Detritivores feed on detritus —breakdown—increases the surface area of detritus particles for microbial action.
Leaching: Soluble inorganic nutrients dissolve in water — percolate through the soil —removed due to leaching action.
Catabolism: Decomposers (bacteria, fungi) release enzymes — decompose detritus — simpler inorganic compounds.
Humification: Simplified detritus— converted to HUMUS
– Humus is a Dark, Amorphous substance.
– Highly resistant to Microbial Action
– Undergoes Decomposition very Slowly.
– Reservoir of nutrients (due to colloidal nature)
Mineralisation: Humus is degraded — releases inorganic substances (CO2, H2O etc) and nutrients (Ca2+, Mg2+,K+ etc)
Factors affecting rate of Decomposition:
Chemical composition – decomposition rate will be slow when detritus rich in lignin and chitin and rate increases when detritus is rich in nitrogen and water soluble substances like sugars.