Dynamics of methane emission and archaeal microbial community in paddy soil amended with different types of biochar.

Biochar, as a valuable and eco-friendly material generated from greenwaste, has a potential to mitigate CH 4 emission in rice paddy soil. However, the response of methanogenesis and associated archaeal community in paddy soil to biochar amendment remains controversial. In this study, we explored the effect of three different biochars (derived from rice straw, orange peel or bamboo powder, respectively) on CH 4 emission and associated archaeal microbial community in paddy soil of southern China within 90 days of anaerobic incubation. Results showed that biochar amendment overall inhibited CH 4 emission in paddy soil. Significant decrease of α-diversity of archaeal community was observed in all samples in the end of incubation as revealed by 16S rRNA gene sequencing, and the addition of biochars mitigated the loss of archaeal biodiversity in paddy soil. Incubation time was found to be the major driver for the succession of archaeal community. Besides, Methanosaeta , Methanocella , Methanobacterium and Methanosarcina were mainly responsible for CH 4 production. In addition, biochars had no significant effect on altering relative abundance of methanogens. Overall, our study demonstrated that the addition of three different types of biochar reduced methane emission and total archaeal diversity, while caused no significant change in methanogenic communities in paddy soil. • The addition of three different types of biochar reduced CH 4 emission in paddy soil. • Biochars mitigated the loss of soil archaeal biodiversity during anaerobic incubation. • Incubation time was the major driver for the succession of archaeal community. • Methanosaeta , Methanocella , Methanobacterium and Methanosarcina were mainly responsible for CH 4 production. • Biochars amendment had little effect on the succession of soil methanogens. [ABSTRACT FROM AUTHOR]