Author(s) |
Weng, Zhe (Han)
Van Zwieten, Lukas
Singh, Bhupinderpal Pal
Tavakkoli, Ehsan
Kimber, Stephen
Morris, Stephen
Macdonald, Lynne M
Cowie, Annette
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Publication Date |
2018-03
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Abstract |
<p>Organo-mineral interactions control the stabilisation of soil organic matter (SOM) in mineral soils. Biochar can enhance these interactions via a range of mechanisms including Al-dominant cation bridging in acidic soils, ligand exchange, H-bonding, and π- π-bonding with polycyclic aromatics. But, field-based evidence of their magnitude is lacking. Here we assessed the role of organo-mineral interactions on the observed biochar-induced negative priming of native soil organic carbon (SOC) in a Ferralsol under annual ryegrass. Using repeated pulse labelling, the magnitude of production and fate of recently photosynthesised <sup>13</sup>C was traced amongst: soil plus root respiration, root biomass, soil aggregates and aggregate-associated C fractions. Biochar (<i>Eucalyptus saligna</i>, 450 °C) amendment (30 Mg ha<sup>−1</sup> ) increased total belowground <sup>13</sup>C recovery by 10% compared to the unamended control over the 12 month sampling period. We detected the greatest quantity of rhizodeposit in the mineral-protected SOM within macroaggregates (250–2000 μm). Through synchrotron-based spectroscopic analysis of bulk soils, we provide evidence of a mechanism for biochar-induced negative priming which is the accumulation of rhizodeposits in organo-mineral (<i>i.e.</i> aggregate-protected and silt/clay-bound) fractions.</p>
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Citation |
Soil Biology & Biochemistry, v.118, p. 91-96
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ISSN |
1879-3428
0038-0717
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Link | |
Publisher |
Elsevier Ltd
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Title |
The accumulation of rhizodeposits in organo-mineral fractions promoted biochar-induced negative priming of native soil organic carbon in Ferralsol
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Type of document |
Journal Article
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Entity Type |
Publication
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