Explain the mechanism of compost formation.
Compost is prepared from farm and town refuse, including vegetable and animal refuse, faecal matter of humans, sewage waste, weeds, crop stubble, straw, forest litter, etc.
Steps in preparation of compost:
(i) A trench of suitable size (4–5 cm long, 1.5–1.8 cm broad, and 1.0–1.8 cm deep) is dug.
(ii) A layer of mixed refuse (about 30 cm thick) is spread in the trench that is well moistened by slurry of cattle dung and water.
(iii) A second layer of mixed refuse is spread in trench till the heap rises to about 45–60 cm above the ground level.
(iv) Top of the heap is then covered by a thin layer of moist earth. This is left for about three months.
(v) Partially decomposed biomass is taken out of the trench and collected in a conical heap that is moistened with earth and is again left for one to two months. The compost is then ready for use.