Effects of storage time and conditions on nutrient solubility ofswine manure

摘要

Effectively managing livestock manure is essential to prevent nutrient loss to the environmental and causing eutrophication. This study investigated the changes of phosphorus (P) and nitrogen (N) solubility in liquid swine manure (SM) under differenttemperatures (4 °C, ambient temperature, 20 °C, and 37 °C) and air availability during a long-term storage. SM storage was conducted for 5 months in winter and 6 months in summer. In winter storage, water extractable P (WEP) in SM first increased by 50% -100% after 4 weeks, then gradually decreased by more than 80%. In summer storage, WEP continue to decrease by 30% - 60%. Increase of temperature decreased P solubility. Anaerobic storage caused pH decrease and had higher P solubility than aerobic storage. N loss and solubility increased with storage time due to the conversion of organic N to ammonia. The mechanism of WEP variation during manure storage needs further study.