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Rolling in the deep: Priming effects in earthworm biopores in topsoil and subsoil

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dc.contributor.author Hoang D.
dc.contributor.author Bauke S.
dc.contributor.author Kuzyakov Y.
dc.contributor.author Pausch J.
dc.date.accessioned 2018-04-05T07:09:11Z
dc.date.available 2018-04-05T07:09:11Z
dc.date.issued 2017
dc.identifier.issn 0038-0717
dc.identifier.uri http://dspace.kpfu.ru/xmlui/handle/net/129564
dc.description.abstract © 2017 Elsevier Ltd Priming effect is the change of soil organic matter (SOM) decomposition due to the addition of labile carbon (C) sources. Earthworms incorporate organic matter into their burrow-linings thereby creating preferred habitats for microorganisms, but the roles of such burrows in priming effect initiation is unknown. Here we study the mechanisms driving SOM decomposition in top- and subsoil biopores and additionally in the rhizosphere. Given the topsoil was newly formed after ploughing 10 months prior to sampling, we hypothesized that (1) SOM accessibility, enzyme activities and efficiency of enzymatic reaction (K a ) are main drivers of different priming effect in biopores vs. bulk soil and rhizosphere, subsoil vs. topsoil and (2) the production of microbial enzymes in biopores depends on microbial community composition. To test these hypotheses, biopores formed by Lumbricus terrestris L. and bulk soil were sampled from topsoil (0–30 cm) and two subsoil depths (45–75 and 75–105 cm). Additionally, rhizosphere samples were taken from the topsoil. Total organic C (C org ), total N (TN), total P (TP) and enzyme activities involved in C-, N-, and P-cycling (cellobiohydrolase, β-glucosidase, xylanase, chitinase, leucine aminopeptidase and phosphatase) were measured. Priming effects were calculated as the difference in SOM-derived CO 2 from soil with or without 14 C-labeled glucose addition. Enzyme activities (V max ) and the catalytic efficiency (K a ) were higher in biopores compared to bulk soil and the rhizosphere, indicating that the most active microbial community occurred at this site. Negative correlations between some enzymes and C:N ratio in bulk soil are explained by higher content of fresh organic C in the topsoil, and the corresponding C and nutrient limitations in the subsoil. The positive correlation between enzyme activities and Corg or TN in biopores, however, was associated with the decrease of C and TN with pore age in the subsoil. In the subsoil, priming effect in biopores was 2.5 times higher than bulk soil, resulting from the favorable conditions for microorganisms in biopores and the stimulation of microbial activities by earthworm mucus. We conclude that earthworm burrows provide not only the linkage between top- and subsoil for C and nutrients, but strongly increase microbial activities and accelerate SOM turnover in subsoil, contributing to nutrient mobilization for roots.
dc.relation.ispartofseries Soil Biology and Biochemistry
dc.subject Biopores
dc.subject Earthworms
dc.subject Microbial hotspots
dc.subject Organic matter decomposition
dc.subject Priming effect
dc.subject Subsoil
dc.title Rolling in the deep: Priming effects in earthworm biopores in topsoil and subsoil
dc.type Article
dc.relation.ispartofseries-volume 114
dc.collection Публикации сотрудников КФУ
dc.relation.startpage 59
dc.source.id SCOPUS00380717-2017-114-SID85022342431


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  • Публикации сотрудников КФУ Scopus [24551]
    Коллекция содержит публикации сотрудников Казанского федерального (до 2010 года Казанского государственного) университета, проиндексированные в БД Scopus, начиная с 1970г.

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