Interaction between dissolved organic carbon and fungal network governs carbon mineralization in paddy soil under co-incorporation of green manure and biochar

Frontiers in Microbiology

Microbiology

Libo Fu¹  Wei Wang¹  Kun Cheng²  Bo Sun³  Ming Liu³  Xiaoyue Wang³ 

[1] Agricultural Environment and Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming, China;Key Laboratory of Poyang Lake Basin Agricultural Resource and Ecology of Jiangxi Province, College of Land Resource and Environment, Jiangxi Agricultural University, Nanchang, China;State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China;State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China;

关键词: C mineralization;    dissolved organic carbon;    green manure;    biochar;    fluorescence spectra;    microbial communities;    co-occurrence network;   

DOI  :  10.3389/fmicb.2023.1233465

 received in 2023-06-02, accepted in 2023-07-31,  发布年份 2023

来源: Frontiers

【 摘 要 】

Legume crops in rice cultivation are typically rotated and incorporated into the soil as green manure to improve soil fertility. Biochar has recently been co-incorporated with green manure to simultaneously stimulate soil organic carbon (SOC) mineralization and increase carbon (C) sequestration. However, few studies examine the effects of the co-incorporation of biochar and green manure on C cycling and the underlying microbial mechanisms in paddy fields. In this study, the effects of the co-incorporation of green manure and biochar on C mineralization, dissolved organic carbon (DOC) characteristics, and microbial community structures were investigated. A pot study was conducted with three treatments: inorganic NPK (NPK), inorganic NPK + green manure (GM), and inorganic NPK + green manure + biochar (GMC). Organic amendments significantly increased cumulative C mineralization, with amounts in the order GMC (3,434 mg·kg−1) > GM (2,934 mg·kg−1) > NPK (2,592 mg·kg−1). Fertilizer treatments had similar effects on DOC concentrations, with amounts in the order GMC (279 mg·kg−1) > GM (255 mg·kg−1) > NPK (193 mg·kg−1). According to fluorescence spectra, the highest microbial humic acid-like fraction and biological index were also in GMC. Co-incorporation of green manure and biochar shifted the composition of bacterial and fungal communities but more importantly, increased fungal network complexity and decreased bacterial network complexity. The increase in fungal network complexity with the increase in DOC concentrations and microbially derived components was the dominant factor in promoting C mineralization. Overall, this study reveals the underlying biochemical mechanism, the interaction between DOC and fungal network of C cycling in paddy soil under the co-incorporation of green manure and biochar management, and provides fundamental knowledge for exploring effective approaches to improve soil fertility and health in the future.

【 授权许可】

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Copyright © 2023 Cheng, Wang, Fu, Wang, Liu and Sun.