Large-scale organic fertilizer production is a key approach to reusing agricultural waste and promoting green agriculture. It requires scientific planning and precise operations to efficiently transform raw materials into finished products and meet the needs of large-scale farming.
Raw material collection and pretreatment are fundamental. Core raw materials are manure from large-scale livestock farms (primarily pig and cow manure, requiring over 50 tons per day), farm straw, and food processing waste. Long-term agreements must be signed with suppliers to ensure a stable supply. The straw is first shredded to 5-10 cm in size before being mixed with a mixture of "2 parts manure + 1 part straw." Microbial inoculants are added to adjust the carbon-nitrogen ratio to 25:1 and the moisture content to 60%-65% to prepare for fermentation. The site must be divided into raw material, fermentation, and processing areas. The fermentation area features hardened flooring, a rainproof canopy, and is equipped with a turner and aeration equipment.
The fermentation process utilizes a combination of processes. First, the mixed raw materials are windrowed into windrows 3-4 meters wide, 1.5-2 meters high, and 20-30 meters long. Windrows are turned every 2-3 days using a windrow compost turning machine, and oxygen is added through an aeration system to maintain a core temperature of 60-70°C for 15-20 days to kill pathogens. The windrows are then transferred to tank-type fermentation silos for a second composting period of 30 days. An intelligent system regulates temperature and humidity to enhance composting maturity.
Pelletization and subsequent processing determine product quality. After fermentation, The fermented raw materials are first screened to remove impurities. If the moisture content is above 25%, they are pre-dried to 20-25%. A 2-3% binder may be added to enhance pellet hardness. The most common pelleting methods used are disc granulators (producing 2-4 mm round pellets with a pellet forming rate exceeding 90%) or double roller granulators (producing 3-6 mm hard pellets without the need for a binder, with an hourly production capacity of 5-10 tons). After pelleting, the pellets are cooled to room temperature in a drum fertilizer cooler. The broken pellets are then screened for reprocessing and tested for moisture content ≤15% and breakage ≤10%. Once these meet the standards, they are automatically packaged in 25 kg or 1 ton packages.
Production requires wastewater and exhaust gas treatment systems to ensure clean production on the organic fertilizer production line. This not only addresses waste pollution but also provides high-quality fertilizer for agriculture, contributing to a sustainable agricultural cycle. Large-scale organic fertilizer production not only transforms waste into valuable resources but also provides high-quality organic fertilizer for agriculture, promoting the development of a sustainable agricultural cycle. This is a key path to achieving sustainable agricultural development.
