Response characteristics of nitrous oxide related microorganisms to biochar addition during chicken manure composting

Composting process is accompanied by the emission of greenhouse gases such as nitrous oxide (N2O). Biochar addition effectively reduced the release of N2O. However, the specific impact mechanism of biochar is unclear. Therefore, the aim of this study was to reveal the response of N2O-related microorganisms to biochar addition during chicken manure composting. Results suggested that the addition of biochar reduced the species of N2O-related microorganisms from 22 to 19, and changed the functional roles. Network analysis further revealed that the addition of biochar weakened the transformation relationship between nitrification and denitrification, which effectively inhibited the denitrification rate. Ultimately, Structural equation models verified that the addition of biochar made core microorganism Ornithinibacillus prevail, which weakened the denitrification during composting. This study identified the core microorganisms that regulated the production of N2O during chicken manure composting, and provided a theoretical basis for the targeted regulation of N2O emission.