Biochar decreases methanogenic archaea abundance and methane emissions in a flooded paddy soil

Le Qi; Zilong Ma; Scott X Chang; Peng Zhou; Rong Huang; Yingyan Wang; Zifang Wang; Ming Gao

doi:10.1016/j.scitotenv.2020.141958

Biochar decreases methanogenic archaea abundance and methane emissions in a flooded paddy soil

Sci Total Environ. 2021 Jan 15:752:141958. doi: 10.1016/j.scitotenv.2020.141958. Epub 2020 Aug 25.

Authors

Le Qi¹, Zilong Ma², Scott X Chang³, Peng Zhou⁴, Rong Huang⁵, Yingyan Wang⁴, Zifang Wang⁴, Ming Gao⁶

Affiliations

¹ College of Resources and Environment, Southwest University, Chongqing 400716, China; Department of Renewable Resources, University of Alberta, Edmonton T6G 2E3, Canada; College of Forestry, Beijing Forestry University, Beijing 100083, China.
² Department of Renewable Resources, University of Alberta, Edmonton T6G 2E3, Canada.
³ Department of Renewable Resources, University of Alberta, Edmonton T6G 2E3, Canada; State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China.
⁴ College of Resources and Environment, Southwest University, Chongqing 400716, China.
⁵ College of Resources and Environment, Southwest University, Chongqing 400716, China; College of Resource, Sichuan Agricultural University, Chengdu 611130, China.
⁶ College of Resources and Environment, Southwest University, Chongqing 400716, China. Electronic address: gaoming@swu.edu.cn.

PMID: 32892054
DOI: 10.1016/j.scitotenv.2020.141958

Abstract

Biochar addition can reduce methane (CH₄) emissions from paddy soils while the mechanisms involved are not entirely clear. Here, we studied the effect of biochar addition on CH₄ emissions, and the abundance and community composition of methanogens and methanotrophs over two rice cultivation seasons. The experiment had the following five treatments: control (CK), chemical fertilizer application only (BC0), and 0.5% (w/w) (BC1), 1% (BC2), and 2% of biochar applied with chemical fertilizers (BC3). The season-wide CH₄ emissions were decreased (P < 0.05) by 22.2-95.7% in biochar application compared with BC0 in the two rice seasons (2017 and 2018). In 2017, biochar application decreased methanogenic archaea (mcrA) but increased methanotrophic bacteria (pmoA) abundances, and decreased the ratio of mcrA/pmoA, as compared with BC0 (P < 0.05). In 2018, the abundance of mcrA was lower in BC2 and BC3 than in BC0 (P < 0.05) but was not different between BC0 and BC1, and the abundance of pmoA was lower in BC1, BC2 and BC3 than in BC0 (P < 0.05). The CH₄ emissions were positively related to abundances of the mcrA gene (P < 0.01) but not to that of the pmoA gene in two rice seasons. Rice grain yield was increased by 62.2-94.1% in biochar addition treatments compared with BC0 in the first year (P < 0.01) and by 29.9-37.6% in BC2 and BC3 compared with BC0 in the second year (P < 0.05). Biochar application decreased CH₄ emissions by reducing methanogenic archaea abundance in the studied flooded paddy soil.

Keywords: Biochar application rate; Interannual variation; Methanogen; Methanotroph; Rice paddy.

MeSH terms

Archaea / genetics
Charcoal
Methane
Oryza*
Soil Microbiology
Soil*

Substances

Soil
biochar
Charcoal
Methane