The production of organic fertilizer is a process of turning organic waste into valuable resources. It involves three main stages: raw material processing, microbial fermentation, and post-processing, ultimately producing fertilizer products suitable for agricultural needs.
At the outset, precise selection of raw materials is crucial. Common materials such as livestock and poultry manure, crop straw, garden branches, and kitchen waste must first be sorted to remove impurities like plastics and metals. Straw materials need to be crushed to less than 5 cm, while livestock and poultry manure undergoes solid-liquid separation to extract the solid portion, ensuring uniform material texture and laying the foundation for subsequent fermentation.
The core process is high-temperature aerobic fermentation. The processed raw materials are sent to a fermentation chamber, where a composting agent containing Bacillus subtilis and other bacteria is added. The carbon-to-nitrogen ratio is adjusted to 25:1, and the moisture content to approximately 60%. During fermentation, microorganisms decompose organic matter, raising the pile temperature to 55-65℃ for 10-15 days to kill insect eggs and pathogens. During this period, a compost turning machine is used to regularly turn the pile to provide oxygen and prevent odors. Composting is complete when the raw materials turn black and soft, emitting a fresh earthy aroma.
The composted material then enters the post-processing stage, where it is processed into different forms of finished products according to market demand. For example, to produce powdered organic fertilizer, the composted material is simply fed into a drying device, where hot air reduces the moisture content to below 20%. Afterward, it is screened to remove incompletely composted impurities before being packaged and shipped. To produce more convenient granular fertilizer, the process is more refined: First, the well-rotted material is crushed to 80-100 mesh to ensure uniform particle size; then, the moisture content is adjusted to 25%-30%, and a small amount of binder such as bentonite is added to enhance the material's agglomeration; next, the material is granulated into particles with a diameter of 2-5 mm using an extrusion granulator, disc granulator, or drum rotary granulator; the freshly formed particles are at a high temperature and have a high moisture content, so they need to be cooled to room temperature by a drum fertilizer cooler, and then the moisture content is controlled to 12%-15% by a drum fertilizer dryer to prevent mold growth during storage; finally, they are screened and graded by a vibrating screen to remove unqualified powder and lumps, and qualified particles can be polished to improve their appearance and reduce dust pollution during transportation. After testing, once the particle hardness, nutrient content, and other indicators meet the standards, they can be quantitatively packaged to become the final granular organic fertilizer.
From organic waste to high-quality fertilizer, this production process not only achieves resource recycling but also provides nutrient-rich and convenient high-quality fertilizer for green agriculture.
