Livestock and poultry manure was once an environmental headache for the livestock industry. Indiscriminate dumping not only pollutes soil and water sources but also emits foul odors. Now, through scientific processing, it can be transformed into efficient and environmentally friendly granular organic fertilizer, achieving resource recycling. This organic fertilizer production process involves multiple precise steps, each with its own technical intricacies.
Pre-treatment is the foundation of the transformation. First, livestock and poultry manure is mixed with auxiliary materials such as straw and sawdust to adjust the moisture content to 50%-70% and the carbon-to-nitrogen ratio to between 20:1 and 40:1, creating suitable conditions for microbial fermentation. A composting agent registered with the agricultural and rural affairs department is added at a rate of 0.1%-0.2% of the material weight. The mixture is then processed using crushing equipment to reduce the particle size to no more than 5 cm, ensuring uniform fermentation.
Fermentation and maturation are the core stages, divided into primary and secondary fermentation. Primary fermentation involves piling the mixture into windrows 1.5-2 meters wide and 1-1.2 meters high. The pile temperature is maintained above 55℃ for more than 15 days through turning or aeration to kill pathogens and insect eggs. If the temperature exceeds 65℃, a compost turning machine is used to turn the pile and lower the temperature. Secondary fermentation allows the pile temperature to naturally drop to ambient temperature, ensuring complete maturation. At this stage, the material is dark brown, odorless, and has a slightly earthy scent.
The matured material needs further processing and shaping to become granules. It is first crushed again using a semi-wet material crusher, then screened using a rotary screen to remove impurities and ensure uniform particle size. Subsequently, trace elements such as calcium and magnesium are added to adjust the fertilizer efficiency according to market demand. The material is then fed into a granulator to form 2-5 mm granules through rolling granulation. The formed granules are then dried at low temperature to reduce moisture content to below 8%, followed by cooling and screening. Unqualified granules are crushed and re-granulated.
Finally, the qualified granules are quantitatively packaged using automatic packaging equipment, labeled with information such as organic matter content and nitrogen, phosphorus, and potassium content, completing the transformation from waste to commercial organic fertilizer. This granular organic fertilizer not only retains the abundant nutrients in animal manure, with potassium utilization rates reaching 50%-80%, but also improves soil quality and increases organic matter content.
Converting livestock and poultry manure into granular organic fertilizer solves the problem of pollution from animal husbandry and provides green fertilizer for agricultural production, achieving a circular economy that transforms waste into valuable resources. With continuous process optimization, this organic fertilizer production technology will play an even more important role in promoting the development of green agriculture.
