Contrasting effects of different field-aged biochars on potential methane oxidation between acidic and saline paddy soils

Zhen Wu; Liying Sun; Yubing Dong; Xintong Xu; Zhengqin Xiong

doi:10.1016/j.scitotenv.2022.158643

Contrasting effects of different field-aged biochars on potential methane oxidation between acidic and saline paddy soils

Sci Total Environ. 2022 Dec 20:853:158643. doi: 10.1016/j.scitotenv.2022.158643. Epub 2022 Sep 9.

Authors

Zhen Wu¹, Liying Sun², Yubing Dong³, Xintong Xu³, Zhengqin Xiong⁴

Affiliations

¹ Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; School of Geographic Information and Tourism, Chuzhou University, Chuzhou 239000, China.
² Callaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Jiangsu Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
³ Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
⁴ Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: zqxiong@njau.edu.cn.

PMID: 36089042
DOI: 10.1016/j.scitotenv.2022.158643

Abstract

There is recognition that biochar addition is an appropriate measure to mitigate methane (CH₄) emissions by promoting potential methane oxidation (PMO) in the field. However, the mechanism for different field-aged biochars and effective duration after field application are not well documented. Based on a long-term field experiment, biochar was field aged and separated from two contrasting acidic (Ba) and saline (Bs) paddy fields. Then, the effects of different aged biochars on PMO in acidic and saline paddy soils were explored by incubation experiment. There were five treatments for each soil group: soil without biochar (CK), biochar-enriched paddy soil (2 or 6 years) (NB), fresh biochar amendment (Bf), aged biochar separated from acidic paddy soil amendment (Ba), and aged biochar separated from saline paddy soil amendment (Bs). Results showed that saline paddy soils had a significantly higher PMO than acidic paddy soils under treatment without biochar, and that PMO in acidic paddy soil was enhanced by various biochar amendments, whereas those biochar amendments had no significant effects on PMO in saline paddy soil. PMO was positively correlated with pmoA abundance, N consumption rate and pH of soil-biochar mixture. Aged biochar separated from different fields had conflicting influences on soil pH, N consumption rate and PMO. Ba lost its initial effect on changing PMO as compared to Bf treatment when added back into acidic paddy soil. To the contrary, the acidic paddy soil NB treatment containing biochar added six years before possessed the highest value of PMO among all ten treatments. This study suggested that acidic paddy soil with biochar amendment could mitigate CH₄ emissions by promoting PMO for a prolonged period, though aged biochar separated from the same field had a limited impact on reducing CH₄ emissions.

Keywords: Aged biochar; Methane (CH(4)); Methanotrophs; Paddy soil; Potential methane oxidation (PMO).

MeSH terms

Charcoal
Methane
Oryza*
Soil*

Substances

biochar
Soil
Methane
Charcoal