What are the core production stages of an organic fertilizer production line?

Organic fertilizer is an essential agricultural input for developing ecological agriculture and improving soil quality. A standardized organic fertilizer production line consists of several closely integrated processes. Among these, six key stages—raw material pretreatment, aerobic fermentation (composting), crushing and blending, granulation, drying, cooling and screening, and final packaging—are critical, as they directly determine both the quality of the organic fertilizer and the efficiency of production.

Raw material pretreatment serves as the starting point. The raw materials—typically organic waste such as livestock and poultry manure, crop straw, or fungal residue—often have high moisture content, contain various impurities, and possess an imbalanced carbon-to-nitrogen (C/N) ratio. During this stage, debris such as stones and plastics is removed. Auxiliary materials like straw or rice husks are added to adjust the moisture content and the C/N ratio, followed by the addition of microbial fermentation agents. This preparation creates the optimal conditions for subsequent aerobic fermentation, preventing issues such as anaerobic decomposition (which causes foul odors) or incomplete composting.
Aerobic fermentation is the core biochemical stage of the entire production line and is crucial for ensuring the organic fertilizer is safe and harmless. The prepared materials are placed into fermentation tanks, where a compost turning machine (compost turner) periodically aerates the pile, maintaining a high-temperature environment of 55°C to 65°C. Sustaining this high temperature for a specific period eliminates insect eggs, pathogens, and weed seeds. Simultaneously, through microbial activity, complex organic matter is gradually converted into stable humus. The duration of the fermentation cycle varies depending on the specific process. Once fully composted, the material becomes loose in texture and loses any unpleasant odor, serving as a high-quality semi-finished product.
Following fermentation, the material moves to the crushing and blending stage. Since the composted material often contains clumps, it is processed through a crusher to ensure a uniform particle size. An automated batching system then adds specific secondary nutrients, trace elements, or functional microbial agents as required. These are thoroughly mixed to stabilize the nutrient content, ensuring the product meets the specific fertilization needs of various crops and soil types, while also preparing the material for granulation.
Granulation is the defining process for producing commercial granular organic fertilizer. Commonly used equipment in the market—such as disc granulators, flat-die pellet machines, and new type organic fertilizer granulators—transforms powdered raw materials into uniform granules. These granules are easier to store, transport, and spread; they generate less dust and allow for a more controlled release of nutrients, marking a crucial step toward the commercialization of organic fertilizers.
Once granulated, the product must undergo drying, cooling, and screening. Since newly formed granules have a high moisture content, the drying process requires precise temperature control to prevent the inactivation of any microbial agents. After cooling, the granules pass through screening equipment to remove fine dust and oversized particles; any substandard material is recycled back into the granulation process, ensuring a consistent particle size in the final product. Some products may also undergo a coating process to achieve a slow-release effect.
The final stage is automated weighing and packaging. Once the organic fertilizer granules have been tested to ensure they meet nutrient standards, they are weighed, bagged, sealed, and placed into storage, ready for distribution.
The entire production line functions as an integrated system. Equipment provided by Huaqiang Heavy Industry—including turners, crushers, and granulators—ensures the stable operation of each stage. By strictly managing every core process, manufacturers can consistently produce safe, efficient organic fertilizers that meet national standards, thereby supporting integrated crop-livestock systems and the protection of arable land.