With the deeper understanding of pig farming, it's discovered that not only pork is edible, but pig manure also holds significant value. Pig feces are a great source of organic fertilizer for agricultural use, enhancing soil fertility. However, applying unfermented fresh pig manure directly can harm plant roots, cause diseases, and grass damage. If pig manure is naturally piled and fermented, it not only takes a long time to pile and has poor fermentation, but also pollutes the surrounding environment, and the transportation of the fermented product is difficult.
The high-temperature aerobic fermentation process involves the decomposition of organic materials by microorganisms, converting them into CO2 and small organic compounds (organic matter), thereby degrading the organic materials in a reduced and stabilized manner. At the same time, the fermentation process generates a significant amount of heat, raising the pile temperature to over 55℃ for an extended period. This effectively eliminates pathogens and weed seeds, achieving the harmless treatment of organic materials and truly realizing the resource utilization of organic waste.

Chemical fertilizers have greatly contributed to the development of modern agriculture, but their long-term and excessive use has led to numerous impacts, such as soil compaction and ecological damage. Particularly, the extensive use of nitrogen and phosphorus has caused a steady increase in the amount of these nutrients migrating into water bodies through agricultural runoff and soil seepage, becoming a significant factor in the increasing eutrophication of lakes, rivers, and reservoirs. Moreover, the nitrate concentration in river and lake waters has sharply risen, affecting drinking water quality. This issue has garnered attention both domestically and internationally. In China, policies have been implemented to tax related products, guiding changes in agricultural fertilizer use. With the growing awareness of environmental protection and the development of green food and ecological agriculture, there is a growing consideration to gradually reduce the use of chemical fertilizers and increase the use of organic and biological fertilizers.

Farmyard manure, such as animal excrement, makes excellent fertilizer. It's rich in nutrients for crop planting and free from chemical concerns. For instance, chicken manure is particularly noteworthy; it's packed with nutrients, including nitrogen, phosphorus, potassium, and other trace elements, offering a balanced profile. Moreover, these elements are several times more concentrated than in cow manure. For poultry farmers, dealing with excrement is a headache, especially with strict environmental regulations. Reusing excrement as fertilizer would truly be a transformation from waste to treasure. However, directly spreading untreated excrement on fields poses numerous hazards, such as pests and diseases, crop scorching, toxic gas production, and slow fermentation. Therefore, farmyard manure must be fermented before use, requiring an airtight, constant-temperature fermentation environment to enhance efficiency and quality.

The issue of handling animal manure, crop straw, and other waste has long plagued governments and enterprises at all levels. There have been many practices using these raw materials to produce organic fertilizers, and the equipment for fermenting organic fertilizers is numerous. Traditional organic fertilizer fermentation equipment mainly includes compost turners, dryers, ventilation systems, etc., which operate primarily in open environments, leading to problems such as nitrogen fertilizer loss and environmental pollution. Moreover, these devices occupy a large area and require a significant investment, hence there is an urgent need for a sealed organic fertilizer fermentation equipment that can quickly achieve fermentation.
In recent years, China's aquaculture industry has developed rapidly, moving towards large-scale and intensive production. At the same time, the waste produced by the industry has also increased significantly. Livestock and poultry manure contain a large amount of organic pollutants, with the COD alone reaching 71.18 million tons, far exceeding the total COD of industrial and domestic wastewater pollutants. Currently, due to factors such as capital and technology, the rate of non-hazardous, resourceful, and commercial treatment of manure is less than 5%. Large-scale livestock and poultry farming has become a major source of rural environmental pollution in China, placing a huge burden on the ecological environment and also one of the main obstacles to the continuous development of the industry. Therefore, converting a vast amount of livestock and poultry waste into commercial organic fertilizer through biological fermentation, turning waste into treasure, aligns with the principles of waste treatment for reduction, resource utilization, non-hazardousness, and ecologicalization, and can generate significant social, ecological, and economic benefits. The fermentation of livestock and poultry manure into fertilizer is divided into anaerobic fermentation and high-temperature aerobic fermentation according to the fermentation process. The former is greatly affected by the climate, has poor odor control, a long composting time, and does not kill pathogens and eggs in the waste thoroughly, affecting the quality of the organic fertilizer, and is therefore rarely used. High-temperature aerobic fermentation utilizes natural or inoculated microorganisms under aerobic conditions to quickly deodorize and decompose the material, characterized by fast fermentation, short cycles, and ease of mechanized operation. The fermentation process can produce temperatures of 60-70°C, killing pathogens and eggs in the waste, resulting in "sanitary fertilizer" that has been widely adopted by most enterprises. Currently, the most recognized composting methods for high-temperature aerobic fermentation are static aeration, strip composting, and compost reactors.