The Fermentation Process of Organic Fertilizer

The production of any kind of qualified and high quality organic fertilizer must go through the process of compost fermentation. Composting is a process in which organic matter is continuously degraded and stabilized by the action of microorganisms under certain conditions, and produces a product suitable for land use.

Composting, an ancient and simple method of treating organic waste and manufacturing fertilizer, has been gaining attention in various countries for its application as it has good ecological significance and brings benefits to agricultural production as research has intensified and methods have been improved. There are many reports that the preparation of seedbeds with decomposed compost can suppress soil-borne diseases. And the antagonistic bacteria that ensue after the high temperature stage of the composting process can make the bacteria count reach a high level; the composting process of each organic matter under the action of microorganisms to achieve a state of less decomposition, stability and easy absorption by crops; at the same time microbial action to reduce the toxic effects of heavy metals within a certain range. It can be seen that composting is a simple and effective method to manufacture bio-organic fertilizer, which is beneficial to the development of ecological agriculture.

Compost Fermentation Process

Composting is actually a form of waste stabilization, but it requires special humidity, aeration conditions and microorganisms to produce a suitable temperature. This temperature is generally considered to be higher than 45°C. Maintaining this high temperature inactivates pathogenic bacteria and kills weed seeds. The organic matter remaining after reasonable composting has a low decomposition rate, is relatively stable and can be easily absorbed by plants. The odor can be greatly reduced after composting.

The composting process involves many different kinds of microorganisms. The number of various microorganisms changes constantly due to changes in raw materials and conditions, so that no microorganism is always dominant in the composting process. Each environment has its own specific microflora, and the diversity of microorganisms allows composting to avoid system collapse despite changes in external conditions.

The composting process is carried out mainly by the action of microorganisms, which are the mainstay of composting and fermentation. There are two sources of microorganisms involved in composting: one is the original large number of microorganisms inside the organic waste; the other is the artificial addition of microbial inoculants. These strains have strong decomposition ability of certain organic waste under certain conditions, with strong activity, rapid reproduction, rapid decomposition of organic matter, etc., can accelerate the process of composting reaction, shorten the composting reaction time.

Composting is generally divided into two kinds of aerobic composting and anaerobic composting. Aerobic composting is the decomposition process of organic materials under aerobic conditions, and its metabolic products are mainly carbon dioxide, water and heat; anaerobic composting is the decomposition process of organic materials under anaerobic conditions, and the final metabolic products of anaerobic decomposition are methane, carbon dioxide and many low molecular weight intermediate products, such as organic acids.

The main microbial species involved in the composting process are bacteria, fungi and actinomycetes. All three microorganisms have mesophilic and hyperthermophilic bacteria.

The population of microorganisms in the composting process changes alternately with the change of temperature as follows: low and medium-temperature flora dominate to medium and high-temperature flora dominate, and medium and high-temperature flora dominate to medium and low-temperature flora. With the extension of composting time, bacteria gradually decreased, actinomycetes gradually increased, mold and yeast at the end of composting significantly reduced.