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  • Jeewani Peduru Hewa
    Zhejiang University
  • Yu Luo
    Zhejiang University
  • Guanghui Yu
    Tianjin University
  • Yingyi FU
    Zhejiang University
  • Xinhua He
    Southwest University, Chongqing
  • Lukas van Zwieten
    Wollongbar Primary Industries Institute
  • Chao Liang
    Chinese Academy of Sciences
  • Amit Kumar
    Leuphana University of Lueneburg
  • Yan He
    Zhejiang University
  • Yakov Kuzyakov
    Georg August University of Gottingen
  • Hua Qin
  • Georg Guggenberger
    Leibniz Universitat Hannover
  • Jianming Xu
    Zhejiang University
Goethite is known to contribute to the co-precipitation of rhizodeposits and thus benefit carbon (C) sequestration, while arbuscular mycorrhizal fungi (AMF) play significant role in soil organic C (SOC), however, the combined effect is less known. To address this paucity in knowledge, we compared the physicochemical stabilization and microbial mineralization of rhizodeposits from maize (Zea mays L.) and the rhizosphere priming effect (RPE) in soils with a combination of goethite addition and AMF inoculation. Here, we showed that compared to the control: i) Co-amendment of AMF and goethite resulted in a 0.6-fold decrease of rhizodeposit derived CO2, and a 2.8-fold larger allocation of rhizodeposits into macro-aggregates, most likely due to precipitation by goethite and macro-aggregate formation stimulated by AMF hyphae. Analyses using μ-FTIR confirmed the spatial distribution of polysaccharides overlapped with Fe–O minerals within macro-aggregates, supporting the concomitant processes of rhizodeposit stabilization and aggregate formation via hyphal-aggregate mineral interactions; ii) Inoculation with AMF accelerated SOC turnover by increasing the RPE (by 6.1 mg C kg−1 day−1, 74% increase) and rhizodeposit stabilization (by 6.2 mg C kg−1 soil day−1, 47% increase). The larger soil priming effect stimulated by AMF was associated with several genera including Solirubrobacter, Pseudomonas and Talaromyces, suggesting these hyper-symbionts were involved in nutrient acquisition (mining hypothesis). Our results enabled the comparison between rhizodeposit stabilization versus rhizodeposit and SOC mineralization, and highlighted the contributions of both goethite (abiotic contribution) and AMF (biotic contribution) to C accrual in a soil-plant system.

Keywords

  • Carbon sequestration AMF Rhizosphere priming effects Rhizodeposition 13C natural abundance Synchrotron-radiation-based spectromicroscopy
Original languageEnglish
Article number108417
JournalSoil Biology and Biochemistry
Volume162
Early online date7 Sept 2021
DOIs
Publication statusPublished - 1 Nov 2021
Externally publishedYes
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