Organic fertilizers will mainly kill harmful microorganisms such as plant pathogens, insect eggs, and weed seeds during the early heating and high temperature stages of composting. However, the main function of microorganisms in this process is metabolism and reproduction, and only a few metabolites are produced. Moreover, these metabolites are unstable and not easily absorbed by plants. In the later cooling period, microorganisms will humify organic matter and produce a large number of metabolites that are beneficial to plant growth and absorption. This process takes 45-60 days.

Composting through this process can achieve three purposes:

First, it is harmless, and the biological or chemical harmful substances in organic waste are harmlessly or safely treated;

Second, it is humification. In the process of decomposition of humified soil organic matter, the simple decomposition products produced will produce new organic compounds, humus, under the action of microorganisms. This is why the humification process is a form of nutrient accumulation;

Third, it produces microbial metabolites. Microorganisms produce a variety of metabolites during metabolism, such as amino acids, nucleotides, polysaccharides, lipids, vitamins, antibiotics, protein substances, etc.

The fermentation process of organic compost is the process of metabolism and reproduction of various microorganisms. The metabolism of microorganisms is the process of decomposition of organic matter. The decomposition of organic matter will inevitably produce energy to increase the temperature. The death, replacement and material form transformation of various organisms and microorganisms in the composting process are carried out simultaneously. Whether from the perspective of thermodynamics, biology or material transformation, the composting fermentation process cannot be completed in a few days or more than ten days. This is why even if various temperature, humidity, moisture, microorganisms and other conditions are well controlled, composting still takes 45-60 days.