Transformation of nitrogen and carbon during composting of manure litter with different methods

In this study, to investigate the nitrogen and carbon characteristics throughout the composting process in different systems, four methods of composting including static treatment (ST), turning treatment (TT), forced aeration treatment (FAT), and forced aeration with acidification treatment (FAAT) were conducted. Organic matter degradation was improved in TT and FAT that accelerated the composting efficiency. The harmless time based on phytotoxicity was significantly shortened in FAT comparing with ST. However, nitrogen loss through ammonia volatilization increased 14.0%. Ammonia volatilization could be significantly decreased to 17.0% after acidification optimization with FAAT. Compared to FAT, the FAAT got an increased nitrous oxide production and decreased methane emission. Generally, the lowest global warming potential value (52.8 kg CO₂-eq/t) was found in FAAT. Therefore, considering the environmental, fertilizer and toxicity indicators, the FAAT composting method is the most promising method, and has the potential to be promoted for implementation in practice.