Organic fertilizer, as a core fertilizer in ecological agriculture, follows the principles of natural cycles in its production process. It requires several rigorous steps to transform various organic wastes into efficient and safe fertilizers. The complete organic fertilizer production process mainly includes seven key steps: raw material collection and screening, pre-treatment, fermentation and maturation, post-treatment, granulation, drying and cooling, and quality inspection and packaging.
Raw material collection and screening are the foundation of production. Organic fertilizer raw materials come from a wide range of sources, including livestock and poultry manure, crop straw, kitchen waste, and garden waste. After collection, strict screening is required to remove impurities such as stones, plastics, and metals. Simultaneously, the materials are classified according to their characteristics, such as rationally combining livestock and poultry manure with high nitrogen content and straw with high carbon content, laying the foundation for subsequent fermentation. This step ensures the purity of the raw materials and prevents harmful substances from affecting fertilizer quality.
The pre-treatment stage aims to optimize fermentation conditions. First, the screened raw materials are crushed; coarse fiber materials such as straw and branches need to be crushed to a suitable particle size to increase the contact area with microorganisms; then, the carbon-nitrogen ratio, moisture content, and pH value of the raw materials are adjusted. Generally, the carbon-nitrogen ratio is controlled between 25:1 and 30:1, and the moisture content is around 60%. Adjusting agents are added to ensure suitable microbial activity. Proper pre-treatment can significantly improve fermentation efficiency.
Fermentation and maturation are the core steps in the organic fertilizer production process, divided into three stages: heating, high temperature, and cooling. The pre-treated raw materials are piled up or placed in fermentation tanks. After inoculating with microbial agents, the microorganisms multiply rapidly, raising the pile temperature to above 55°C, which is maintained for several days to kill pathogens, insect eggs, and weed seeds; then the temperature gradually decreases, and the microorganisms further decompose the organic matter, making the raw materials mature and stable. During fermentation, regular turning and ventilation are required to ensure oxygen supply and promote microbial metabolism.
Post-treatment, granulation, drying and cooling, and quality inspection and packaging are the final lines of defense to ensure product quality. The matured material is first screened and dried to remove residual impurities and adjust the moisture content to a suitable range; then it enters the granulation stage, where the loose material is processed into granules using granulation equipment. This not only facilitates storage, transportation, and application but also reduces nutrient loss. After granulation, the granules undergo drying and cooling to reduce their moisture content to the standard level (generally not exceeding 15%) and lower their temperature to room temperature, preventing mold growth during storage due to high temperature and humidity. This is followed by rigorous quality control, testing for indicators such as organic matter content, pH value, and heavy metal content to ensure compliance with national organic fertilizer standards. Qualified products are then weighed, packaged, and stored for sale.
These seven steps are interconnected, forming a complete organic fertilizer making process. This process not only achieves the resource utilization of organic waste but also guarantees the safety and effectiveness of the organic fertilizer, providing crucial support for green agricultural development.
