Decomposition is a process in which the detritus (dead plants, animals and their excreta) are breaken down in to simple organic matter by the decomposers. It is an essential process for recycling and balancing the nutrient pool in an ecosystem
Nature of decomposition
The process of decomposition varies based on the nature of the organic compounds, i.e., some of the compounds like carbohydrate, fat and protein are decomposed rapidly than the cellulose, lignin, chitin, hair and bone.
Mechanism of decomposition
Decomposition is a step wise process of degradation mediated by enzymatic reactions. Detritus acts as a raw material for decomposition. It occurs in the following steps.
a. Fragmentation –
The breaking down of detritus into smaller particles by detritivores like bacteria, fungi and earth worm is known as fragmentation. These detritivores secrete certain substances to enhance the fragmentation process and increase the surface area of detritus particles.
b. Catabolism –
The decomposers produce some extracellular enzymes in their surroundings to break down complex organic and inorganic compounds in to simpler ones. This is called catabolism
c. Leaching or Eluviation –
The movement of decomposed, water soluble organic and inorganic compounds from the surface to the lower layer of soil or the carrying away of the same by water is called leaching or eluviation.
d. Humification –
It is a process by which simplified detritus is changed into dark coloured amorphous substance called humus. It is highly resistant to microbial action, therefore decomposition is very slow. It is the reservoir of nutrients.
e. Mineralisation –
Some microbes are involved in the release of inorganic nutrients from the humus of the soil, such process is called mineralisation.
Factors affecting decomposition
Decomposition is affected by climatic factors like temperature, soil moisture, soil pH ,oxygen and also the chemical quality of detritus.