Material Composition and Transformation Law of Three Kinds of Livestock and Poultry Manures During the Composting Process
This study aimed to investigate the material composition and transformation during composting of different kinds of livestock and poultry manures. Fresh cow manure (R1), pig manure (R2), and chicken manure (R3) were used as raw materials, and 10% corn stalk was selected as the leavening agent for aerobic static composting. The following results were obtained. After 30 days of aerobic composting, the mass reduction index of the R1, R2, and R3 piles was 48.94%, 47.94%, and 52.94%, respectively. Especially in the first stage (0–10 days) of the composting reaction, the mass reduction indices of the R1, R2, and R3 piles were significant, which were 21.45%, 22.73%, and 23.73%, respectively. During the composting process, the percentage of dissolved organic carbon in TC showed a downward trend, decreasing to 51.33% ± 1.25%, 57.35% ± 3.21%, and 52.34% ± 2.15%, for R1, R2, and R3, respectively. The percentage of ammonia nitrogen (AN) in total nitrogen (TN) in the piles R1, R2, and R3 first showed an increasing trend and then decreased, showing the highest values of 7.38%, 8.11%, and 9.22%, respectively.