Mechanisms of mitigating nitrous oxide emission during composting by biochar and calcium carbonate addition

Xinyi Yang; Pengpeng Duan; Yubo Cao; Kelin Wang; Dejun Li

doi:10.1016/j.biortech.2023.129772

Mechanisms of mitigating nitrous oxide emission during composting by biochar and calcium carbonate addition

Bioresour Technol. 2023 Nov:388:129772. doi: 10.1016/j.biortech.2023.129772. Epub 2023 Sep 19.

Authors

Xinyi Yang¹, Pengpeng Duan¹, Yubo Cao², Kelin Wang¹, Dejun Li³

Affiliations

¹ Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; Guangxi Key Laboratory of Karst Ecological Processes and Services, Huanjiang Observation and Research Station for Karst Ecosystems, Chinese Academy of Sciences, Huanjiang 547100, China; Institutional Center for Shared Technologies and Facilities of Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
² Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China.
³ Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; Guangxi Key Laboratory of Karst Ecological Processes and Services, Huanjiang Observation and Research Station for Karst Ecosystems, Chinese Academy of Sciences, Huanjiang 547100, China; Institutional Center for Shared Technologies and Facilities of Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China. Electronic address: dejunli@isa.ac.cn.

PMID: 37734484
DOI: 10.1016/j.biortech.2023.129772

Abstract

To investigate the mechanisms underlying effects of biochar and calcium carbonate (CaCO₃) addition on nitrous oxide (N₂O) emissions during composting, this paper conducted a systematic study on mineral nitrogen (N), dissolved organic carbon (C) and N, sources of N₂O, and functional genes. Biochar and CaCO₃ addition decreased N₂O emissions by 26.5-47.8% (9.5-96.9 mg N kg^-1 dw) and 13.9-37.4% (12.0-121.0 mg N kg^-1 dw) compared to the control (14.3-179.7 mg N kg^-1 dw), respectively. The mitigation of N₂O emission was caused by decreased contribution of ammonia-oxidizing bacteria (AOB) and fungi to N₂O production due to diminished AOB amoA, fungal nirK and P450 gene abundances, or by stimulated N₂O reduction to N₂ owing to increased abundances of nosZⅠ and nosZⅠⅠ genes under biochar and CaCO₃ addition. The findings suggest that the addition of biochar or CaCO₃ is effective in mitigating N₂O emission during composting.

Keywords: Biochar; CaCO(3); Inhibitors; Isotopocule approach; N(2)O production pathways.

MeSH terms

Betaproteobacteria*
Calcium Carbonate
Charcoal
Composting*
Nitrous Oxide / analysis
Soil
Soil Microbiology

Substances

Nitrous Oxide
biochar
Soil
Calcium Carbonate
Charcoal