Self-cleaning of the soil
Purification is the process of cleaning the soil of foreign elements or pollutants , i. e. to render the soil back to a pure state. Self-cleaning of the soil is influenced by characteristics like mechanical structure, physical and chemical characteristics of the soil, and type and quantity of microflora, flora and fauna. The most important factor is the main constituent of waste substratum in the soil. Natural-borne ground microbes and saprophytes perform decomposition of proteins to nitrogen and simple compounds. Some plants, in symbiosis with bacteria, can fix nitrogen compounds into glutamate. Decomposition of large quantities of cellulotic and other carbohydrate biomass is influenced by cellulolitic bacteria and fungi. In the case of low oxygen concentration, decomposition is directed into humification , and if oxygen is lacking, putrefaction caused by anaerobic bacteria occurs. If such is the case, malodorous gas is released.