pH is one of the important factors affecting the growth of microorganisms. Studies have shown that the suitable pH for general microorganisms is neutral and slightly alkaline. If the pH is too high or too low, it will affect the smooth progress of composting.

The optimal pH of livestock manure compost rich in cellulose and protein is 7.5-8.0. When pH ≤ 5.0, the degradation rate of the substrate is almost 0. When pH ≥ 9.0, the degradation rate of the substrate decreases, and a large amount of ammonia nitrogen volatilizes. . According to the literature, the U.S. Environmental Protection Agency states that the pH of a compost mix should be 6-9.

pH has an important impact on microbial activity and nitrogen preservation. Generally, the pH of raw materials is required to be 6.5. Aerobic fermentation generates a large amount of ammonia nitrogen, which increases the pH. The entire fermentation process is in an alkaline environment, and high pH increases nitrogen loss. Pay attention to pH during factory-based rapid fermentation. You can adjust the pH of the material by adding an appropriate amount of chemical substances as protective agents. Add straw when composting. Since straw can produce a large amount of organic acids during the decomposition process, lime needs to be added to neutralize it.

When livestock manure is added to straw, lime equivalent to 2%-3% of the straw mass should first be added to the straw to adjust the pH and destroy the waxy layer on the surface of the straw to facilitate water absorption, and then mix it with livestock manure . If possible, adding some acidic phosphogypsum to adjust the pH will also have a good effect.