Organic fertilizer fermentation is the core process of converting organic waste into high-quality fertilizer, and a crucial step in organic fertilizer production. Its effectiveness directly determines the nutrient content, maturity, and application value of the organic fertilizer. The key factors affecting fermentation are interrelated and mutually restrictive. Precisely controlling these factors is essential for achieving efficient fermentation in organic fertilizer production process.
The carbon-to-nitrogen ratio is fundamental to successful fermentation. Microorganisms require a balanced carbon and nitrogen supply, with an ideal ratio of 25:1 to 30:1. Insufficient carbon sources lead to low microbial activity and slow fermentation; excessive nitrogen sources can cause ammonia volatilization and nutrient loss. In production, raw materials should be rationally combined, such as scientifically proportioning carbon-rich materials like straw and sawdust with nitrogen-rich materials like livestock manure and soybean meal.
Moisture content directly affects microbial metabolism. The optimal moisture content is 55% to 65%, at which point microorganisms can efficiently decompose organic matter. Excessive moisture leads to poor aeration, causing anaerobic fermentation and the production of harmful gases such as hydrogen sulfide; insufficient moisture inhibits microbial activity and halts fermentation. Moisture can be adjusted by drying or adding water, using the criterion that the material forms a clump when squeezed by hand but crumbles when released.
Aeration is a key guarantee for aerobic fermentation. Aerobic microorganisms require sufficient oxygen; insufficient aeration leads to anaerobic fermentation, reducing fermentation efficiency and fertilizer quality. In production, aeration can be improved by using compost turning machines and adding ventilation pipes. The turning frequency should be adjusted according to the fermentation temperature and material condition.
Temperature is an important indicator of the fermentation process. The optimal fermentation temperature is 55℃ to 65℃, which accelerates organic matter decomposition and kills pathogens and weed seeds. Low temperatures require checking the carbon-to-nitrogen ratio and moisture content, and timely turning to increase the temperature; high temperatures require adding water to cool down and prevent nutrient loss.
In addition, the pH value should be maintained within the appropriate range of 6.5 to 8.5. Excessive acidity or alkalinity will inhibit microbial activity and can be adjusted by adding lime or gypsum. In summary, precise control of these key factors is essential for efficient and high-quality organic fertilizer fermentation, providing strong support for green agricultural development.
