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Microbial formation and stabilisation of soil organic carbon is regulated by carbon substrate identity and mineral composition

Wang, Shuang ; Redmile-Gordon, Marc ; Shahbaz, Muhammad LU ; Ge, Tida ; Zhang, Ming ; Wu, Yichao ; Liu, Jun ; Huang, Qiaoyun and Cai, Peng (2022) In Geoderma 414.
Abstract
The view that soil organic C (SOC) is formed mainly from non-metabolised and recalcitrant organic residues is being challenged by an emerging view that metabolic by-products form more stable associations with soil minerals. However, the effects of C substrate identity and soil mineral composition (and interactions) on microbial physiology and SOC formation are still not well understood. We added contrasting substrates (glucose, alanine and a mixture of glucose, alanine, and oxalic acid) into artificial soils of varying mineral composition (montmorillonite, kaolinite, and kaolinite plus goethite and hematite) for 12 weeks. We found that glucose led to 1.45 and 1.75 times more SOC formation than alanine and the mixed substrate, respectively.... (More)
The view that soil organic C (SOC) is formed mainly from non-metabolised and recalcitrant organic residues is being challenged by an emerging view that metabolic by-products form more stable associations with soil minerals. However, the effects of C substrate identity and soil mineral composition (and interactions) on microbial physiology and SOC formation are still not well understood. We added contrasting substrates (glucose, alanine and a mixture of glucose, alanine, and oxalic acid) into artificial soils of varying mineral composition (montmorillonite, kaolinite, and kaolinite plus goethite and hematite) for 12 weeks. We found that glucose led to 1.45 and 1.75 times more SOC formation than alanine and the mixed substrate, respectively. Montmorillonite based soils gained approximately 1.3 times more SOC compared to the other two soils. Compared with kaolinite-only soils, the inclusion of goethite and hematite had a positive effect on total SOC, extracellular C and biologically stable C when amended with alanine, but a negative effect on these SOC fractions when amended with glucose. Soils with greater SOC formation were associated with high microbial C use efficiency (CUE) and extracellular C, suggesting that spatial allocation by the microbial biomass is pivotal for creating stable SOC. Fungi-dominated soils typically had a higher CUE, which was positively correlated with the formation of new SOC. These results suggest that the identity of plant inputs will have a strong bearing on the formation of SOC via interactions with the soil microbial community and soil mineralogy. (Less)
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author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Geoderma
volume
414
article number
115762
pages
9 pages
publisher
Elsevier
external identifiers
  • scopus:85124694106
ISSN
0016-7061
DOI
10.1016/j.geoderma.2022.115762
language
English
LU publication?
yes
id
1f72265d-5916-43a9-9a2b-d04ae65af13c
date added to LUP
2022-02-19 14:06:18
date last changed
2022-08-22 15:15:40
@article{1f72265d-5916-43a9-9a2b-d04ae65af13c,
  abstract     = {{The view that soil organic C (SOC) is formed mainly from non-metabolised and recalcitrant organic residues is being challenged by an emerging view that metabolic by-products form more stable associations with soil minerals. However, the effects of C substrate identity and soil mineral composition (and interactions) on microbial physiology and SOC formation are still not well understood. We added contrasting substrates (glucose, alanine and a mixture of glucose, alanine, and oxalic acid) into artificial soils of varying mineral composition (montmorillonite, kaolinite, and kaolinite plus goethite and hematite) for 12 weeks. We found that glucose led to 1.45 and 1.75 times more SOC formation than alanine and the mixed substrate, respectively. Montmorillonite based soils gained approximately 1.3 times more SOC compared to the other two soils. Compared with kaolinite-only soils, the inclusion of goethite and hematite had a positive effect on total SOC, extracellular C and biologically stable C when amended with alanine, but a negative effect on these SOC fractions when amended with glucose. Soils with greater SOC formation were associated with high microbial C use efficiency (CUE) and extracellular C, suggesting that spatial allocation by the microbial biomass is pivotal for creating stable SOC. Fungi-dominated soils typically had a higher CUE, which was positively correlated with the formation of new SOC. These results suggest that the identity of plant inputs will have a strong bearing on the formation of SOC via interactions with the soil microbial community and soil mineralogy.}},
  author       = {{Wang, Shuang and Redmile-Gordon, Marc and Shahbaz, Muhammad and Ge, Tida and Zhang, Ming and Wu, Yichao and Liu, Jun and Huang, Qiaoyun and Cai, Peng}},
  issn         = {{0016-7061}},
  language     = {{eng}},
  month        = {{05}},
  publisher    = {{Elsevier}},
  series       = {{Geoderma}},
  title        = {{Microbial formation and stabilisation of soil organic carbon is regulated by carbon substrate identity and mineral composition}},
  url          = {{http://dx.doi.org/10.1016/j.geoderma.2022.115762}},
  doi          = {{10.1016/j.geoderma.2022.115762}},
  volume       = {{414}},
  year         = {{2022}},
}