ECOSYSTEM

. D ECOMPOSITION You may have heard of the earthworm being referred to as the farmer’s ‘friend’. This is so because they help in the breakdown of complex organic matter as well as in loosening of the soil. Similarly, decomposers break down complex organic matter into inorganic substances like carbon dioxide, water and nutrients and the process is called decomposition .

Dead plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter, constitute detritus , which is the raw material for decomposition. The important steps in the process of decomposition are fragmentation, leaching, catabolism, humification and mineralisation. Detritivores (e.g., earthworm) break down detritus into smaller particles. This process is called fragmentation.

By the process of leaching, water- soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts. Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as catabolism . It is important to note that all the above steps in decomposition operate simultaneously on the detritus (Figure .

). Humification and mineralisation occur during decomposition in the soil. Humification leads