Decomposition of dead remains or matter of animal and plant is carried out by microorganisms like bacteria, fungi, etc. The soil pH affects the composition of acidophilic and basophilic microorganisms.
Decomposition is largely an oxygen requiring process. In the presence of oxygen, complete degradation of substance occurs while in the absence of oxygen, there will be an incomplete degradation. Similarly, temperature and soil moisture are important as warm and moist environment favour decomposition whereas low temperature and anaerobiosis inhibit decomposition resulting in build up of organic materials.