In organic fertilizer production, fermentation and composting are the core steps in transforming organic waste into high-quality fertilizer. This not only achieves resource utilization of waste but also kills harmful bacteria and insect eggs, avoiding the risk of "burning seedlings" and improving fertilizer efficiency. The process must follow a scientific procedure and control key parameters. The specific steps are as follows:
Step 1: Raw Material Pretreatment. Select organic raw materials such as livestock and poultry manure, straw, and kitchen waste. First, remove impurities such as plastic and metal. Then, crush large materials such as straw into 3-5 cm pieces to increase the contact area for microorganisms. Simultaneously, adjust the raw materials according to a carbon-to-nitrogen ratio of 25:1-30:1, typically using 3-4 parts livestock and poultry manure to 1 part straw, ensuring a balanced nutritional intake for microbial growth and avoiding the problems of slow fermentation due to excessive carbon and foul odor due to excessive nitrogen.
Step 2: Adjusting Moisture and Inoculating with Microorganisms. Mix the prepared raw materials evenly and adjust the moisture content to 50%-60%. The standard for judgment is that it can be formed into a ball when squeezed in the hand, but crumbles easily when dropped, with slight water stains between the fingers but not dripping. Following this, a compound microbial inoculant is inoculated. One kilogram of inoculant can treat 10 tons of material. It needs to be mixed with rice bran and evenly sprinkled in to accelerate fermentation and shorten the composting cycle.
The third step is composting. The mixed material is piled into a heap 1.5-2 meters wide and 0.8-1.5 meters high. The bottom is supported by wooden sticks to enhance aeration. In winter, it can be covered with plastic film for insulation. The initial 1-3 days of fermentation are the heating period, with the heap temperature rapidly rising above 50℃. This is followed by a 3-5 day high-temperature period, maintaining 60-65℃ to effectively kill pathogens and weed seeds. Finally, the temperature gradually drops to room temperature, completing the main fermentation.
The fourth step is regular turning of the heap using a compost turning machine. Turning the heap is crucial for ensuring aerobic fermentation. During the heating period, turn it every 2-3 days; during the high-temperature period, turn it daily; and during the cooling period, turn it every 5-7 days. Each time the heap is turned, the outer layer of material should be moved to the inside, and the inside layer of material should be moved to the outside, breaking up clumps, adding oxygen, and preventing anaerobic fermentation that produces foul odors.
The fifth step is maturity assessment and aging. When the compost pile is dark brown, loose in texture, odorless with a pleasant earthy aroma, and its temperature matches the ambient temperature, it is considered basically mature.
The entire fermentation and maturation process for organic fertilizer production takes approximately30days. Strictly following the above steps and controlling the four key factors—carbon-nitrogen ratio, moisture, temperature, and aeration—will ensure the production of safe and efficient organic fertilizer, providing sufficient nutrients for crop growth and contributing to the development of ecological agriculture.
