HYNKWZSN

3682

3 mai 2021 14:57

3 mai 2021 14:58

Organic and conventional agricultural systems present differences in soil microbial biomass, activity and community composition. However, data concerning the network of correlations among the microbial members in agricultural soils are too limited. In this paper, we examined structural characteristics of the network of these correlations developed in two soils of different legacy (an organic maize (O) and a conventional barley cultivation (C)) cultivated with lettuce (Lactuca sativa L.) plants in a pot experiment. Further, in each soil, inoculation with Plant Growth Promoting Rhizobacteria (PGPR) took place once: Bacillus subtilis (Ba; gram-positive), Pseudomonas fluorescens (Ps; gram-negative), both inoculants (Ps + Ba) and a control without inoculants. We considered inoculation as perturbations for the rhizosphere soil microbes and we estimated the robustness of the soil microbial networks denoting their ability to retain connectivity. Networks from all treatments exhibited positive values of modularity, small-worldness index (SW) >1 and clustering coefficient > 0.4, indicating modular structure, small world properties and the predominance of direct connections. The network in C control exhibited higher values of density and centrality and lower values of fragmentation and SW compared to O control. In organic system, the highest fragmentation (0.55 and 0.62) and SW values (4.98 and 5.48) were in control and co-inoculated soils respectively while in conventional system the highest values were in soils with Ba or Ps inoculants; fragmentation 0.52 (Ba) and 0.48 (Ps), SW 3.54 (Ba) and 4.14 (Ps). The robustness of the soil microbial communities depended on soil legacy (prior management system) as well as whether each inoculant applied individually or jointly, while the type of inoculant was insignificant.

None

• AB - Modalité bio
• FREDO biologie et travail du sol
• FREDO santé végétale
• GEO Grèce
• microbial community
• rhizosphere

• modularity
• network analysis
• organic cultivation
• small-world
• soil legacy

Applied Soil Ecology

167

104028

November 1, 2021

1 novembre 2021

10.1016/j.apsoil.2021.104028 Le DOI est une URL unique de référencement d'une publication. Il est donc plus fiable et permanent qu'une URL classique

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