Organic fertilizer, hailed as "the soil's nutrient meal," uses animal and plant waste as raw materials. Through scientific processing, it not only achieves resource utilization of waste but also improves soil texture and enhances crop quality. While organic fertilizer production may seem simple, it involves rigorous scientific logic, primarily divided into four core stages: raw material pretreatment, high-temperature fermentation, composting and aging, and final shaping.
Raw material pretreatment is the foundation of production, with screening, crushing, and proportioning being key. Raw materials are widely available, including livestock and poultry manure, straw, fruit peels and vegetable leaves, and distiller's grains and cakes. First, impurities such as stones and plastics must be removed to avoid affecting fertilizer efficiency and the soil environment. Then, coarse and hard raw materials like straw are crushed to increase the contact area with microorganisms. Finally, various raw materials are mixed in proportion, adjusting the carbon-to-nitrogen ratio to 25:1-30:1. This ratio optimizes microbial activity, laying the foundation for subsequent fermentation.
High-temperature fermentation is crucial in organic fertilizer production and is the core stage of sterilization and composting. The pre-treated raw materials are piled into heaps 1.5-2 meters high, inoculated with composting agents, and the moisture content is controlled at 55%-60%. During fermentation, microorganisms decompose the organic matter in the raw materials, releasing a large amount of heat. The temperature of the heap will rise to above 55℃ and last for 5-7 days. This process kills pathogens, insect eggs, and weed seeds in the raw materials and breaks down large organic molecules into smaller molecules that are easily absorbed by crops. During this period, a compost turning machine is needed to regularly turn the heap, replenish oxygen, regulate temperature, and ensure uniform fermentation.
Finally, there is the processing and shaping stage. Granular organic fertilizer production is currently the mainstream and widely used form in the market, and its process is more refined and standardized. First, according to different crops and soil requirements, the composted material is secondarily crushed and finely sieved to thoroughly remove incompletely decomposed impurities and coarse particles, ensuring uniform raw material texture. Then, an appropriate amount of binder is added to the crushed and sieved material and thoroughly mixed to ensure the subsequent granulation effect. The mixture is then fed into a granulator, and granulated into uniform particles using a disc granulator or a new type organic fertilizer granulator. After granulation, the wet granules are fed into a dryer, where the temperature is controlled at 80-100℃, and dried until the moisture content is below 15% to prevent mold growth. The dried granules are then cooled to room temperature in a cooler and subjected to a second screening to remove unqualified broken and large particles. Finally, they are weighed, packaged, and stored. For powdered organic fertilizer, the granulation, drying, and cooling steps can be omitted; the granules can be directly packaged after crushing and screening. Thus, a pile of unremarkable waste is transformed into high-quality organic fertilizer.
The entire organic fertilizer production process follows the concept of ecological recycling, requiring no chemical additives. This solves the waste pollution problem and produces green and environmentally friendly fertilizer, providing strong support for the sustainable development of modern agriculture.
