Waste Generation and Management — BIOLOGY STD 9 — Question

The rotting and conversion of organic waste into manure is known as composting. The product formed after composting is called compost.

Method of preparing compost:

(i) A trench of about 5 m long, 1.5 m wide and 1.5 m deep is dug.

(ii) A 30 cm thick layer of well-mixed refuse and waste is spread on it. This layer is completely wetted with a watery mixture of cow dung and some mud.

(iii) A second layer of mixed refuse is spread over the first layer, till the heap rises about half a metre.

(iv) The set-up is kept undisturbed for about 3 months, during which water is sprinkled over it at regular intervals.

(v) A trench is then dug, its material is taken out and rearranged in conical heaps and covered with a layer of soil.

(vi) After 50-60 days, compost is ready for use in cultivation fields or in garden flower beds, etc.