(FAQ)What types of microbial agents are used in bio-organic fertilizers?

In the context of bio-organic fertilizer production line, the various microbial agents are often conflated; in reality, they perform two entirely different "jobs." One group works within the fermentation tanks, transforming manure into fertilizer, while the other group must remain alive upon entering the soil, where it functions within the rhizosphere. Using the wrong type of microbes or adding them at the wrong stage can significantly diminish the product's effectiveness.

1. Fermentation Agents

These microbes are introduced during the composting phase. Their task is to decompose, mature, and deodorize organic materials. Common examples include Bacillus species, actinomycetes, yeasts, lactic acid bacteria, and cellulolytic (cellulose-degrading) bacteria. They work in succession across different temperature ranges to accelerate heating, shorten the fermentation cycle, and reduce odors. Yeasts ferment organic matter and help loosen the material, while lactic acid bacteria break down lignin and cellulose, while also inhibiting harmful microorganisms. These microbes do not need to remain alive in the final product; their work is essentially complete once fermentation concludes.

2. Functional Microbial Agents

These are the key components that distinguish bio-organic fertilizers from standard organic fertilizers. They must be added before or during the granulation process, with the goal of entering the soil alive and successfully colonizing it. Common examples include Bacillus subtilis, which aids in nitrogen fixation, enhances stress resistance, and suppresses soil-borne pathogens; Bacillus megaterium, which excels at solubilizing phosphorus; Bacillus mucilaginosus (silicate bacteria), which focuses on solubilizing potassium and releasing secondary and trace elements; and Bacillus licheniformis, which specializes in disease resistance and the elimination of harmful bacteria. Their primary role is not "making fertilizer," but rather "nurturing the soil." The timing of the addition of these functional microbes directly determines how many viable (living) cells remain in the final product. A reliable approach is to perform a secondary mixing step before granulation, ensuring the microbial agents are encapsulated within the granules. This protects them from the high temperatures encountered during the drying process, allowing for a viability retention rate of over 80%. In short, fermentation agents are responsible for "creating the fertilizer," while functional agents are responsible for "delivering the intended benefits." Only by clearly distinguishing between these two roles can one truly master the production of bio-organic fertilizers.