High-quality organic fertilizer composting fermentation process
High-quality organic fertilizer composting fermentation process generally takes 45-60 days. This is because in the early stage of composting and in the high temperature stage, harmful microorganisms such as pathogenic bacteria, eggs and weed seeds are killed, but the main role of microorganisms in this process is metabolism and reproduction, but only a small amount is produced. Metabolites, and these metabolites are also unstable and are not easily absorbed by plants. During the later cooling period, the microorganisms will undergo humification of organic matter, and in the process, a large number of metabolites beneficial to plant growth and absorption will be produced. This process takes 45-60 days. Composting through this process can achieve three purposes, one is harmless; the second is humification; the third is the production of a large number of microbial metabolites such as various antibiotics, protein substances.
The fermentation process of organic compost can be divided into the following four stages.
In the early stage of composting, the microorganisms in the compost were mainly medium-temperature and aerobic, and the most common were non-spore bacteria, spore bacteria and mold. They start the fermentation process of composting, and under the aerobic conditions, they decompose and easily decompose organic substances (such as simple sugars, starches, proteins, etc.), generate a lot of heat, and continuously increase the compost temperature, rising from 20 °C to 40 °C. It is a fever phase, or a medium temperature phase.
High temperature stage
As the temperature increases, the hot microbes gradually replace the moderate temperature species and play a leading role. The temperature continues to rise, generally reaching 50 ° C or more within a few days, entering the high temperature stage.
In the high temperature stage, the hot actinomycetes and the hot fungi become the main species. They strongly decompose complex organic substances (such as cellulose, hemicellulose, pectin substances, etc.) in the compost, accumulate heat, and the compost temperature rises to 60-70 ° C, even up to 80 ° C.
Most of the heat-producing microorganisms also die or go to sleep (20d or more), which plays an important role in accelerating the composting of compost. Improper composting, only a short period of high temperature, or no high temperature at all, so the maturity is very slow, and it does not reach the semi-fried state in half a year or longer.
When the high temperature stage lasts for a certain period of time, most of the cellulose, hemicellulose, and pectin substances have been decomposed, leaving complex components (such as lignin) that are difficult to decompose and newly formed humus, and the activity of microorganisms is weakened and the temperature gradually decline. When the temperature drops below 40 ° C, the moderate temperature microorganisms become the dominant species.
If the cooling stage comes early, it indicates that the heaping conditions are not ideal and the decomposition of plant matter is not sufficient. At this time, the pile can be turned over, and the piled materials are mixed well to cause a second heat generation and temperature rise to promote the composting of the compost.
Decomposed and fattening stage
After composting, the volume is reduced, and the temperature of the pile is lowered to slightly higher than the temperature. At this time, the compost should be compacted, resulting in an anaerobic state, which weakens the mineralization of organic matter, so as to facilitate fertilizer conservation.
Composting is actually a form of waste stabilization, but it requires special humidity, aeration conditions and microorganisms to produce the right temperature. Studies have shown that heating at a certain temperature for a period of time can destroy pathogens and weed seeds. It is usually heated at a temperature of 60-70 ° C (wet heat) for 5-10 min (minutes). It can destroy the activity of non-dormant bodies of non-spore bacteria and spore bacteria. Using heat sterilization, heating at 70 ° C for 30 min (minutes) can eliminate pathogens in the sludge.
However, at lower temperatures (50-60 ° C), some pathogens can be inactivated for up to 60 days. Therefore, it is necessary to maintain a temperature above 60 °C for a period of time during the composting process. The organic matter remaining after reasonable composting has a low decomposition rate, is relatively stable, and is easily absorbed by plants. The odor after composting can be greatly reduced.