Résumé
Intensive land use practices necessary for providing food and raw materials are known to have a deleterious effect on soil. However, the effects that such practices have on soil microbes are less well understood. To investigate the effects of land use intensification on soil microbial communities we used a combined T-RFLP and pyrosequencing approach to study bacteria, archaea and fungi in spring and autumn at five long term observatories (LTOs) in Europe; each with a particular land use type and contrasting levels of intensification (low and high). Generally, due to large gradients in soil variables, both molecular methods revealed that soil microbial communities were structured according to differences in soil conditions between the LTOs, more so than land use intensity. Moreover, variance partitioning analysis also showed that soil properties better explained the differences in microbial communities than land use intensity effects. Predictable responses in dominant bacterial, archaeal and fungal taxa to edaphic conditions (e.g. soil pH and resource availability) were apparent between the LTOs. Some effects of land use intensification at individual field sites were observed. However, these effects were manifest when land use change affected soil conditions. Uniquely, this study details the responses of different microbial groups to soil type and land use intensification, and their relative importance across a range of European field sites. These findings reinforce our understanding of drivers impacting soil microbial community structure at both field and larger geographic scales.
Auteurs, date et publication :
Auteurs Bruce C. Thomson , Emilie Tisserant , Pierre Plassart , Stéphane Uroz , Rob I. Griffiths , S. Emilia Hannula , Marc Buée , Christophe Mougel , Lionel Ranjard , Johannes A. Van Veen , Francis Martin , Mark J. Bailey , Philippe Lemanceau
Publication : Soil Biology and Biochemistry
Date : 2015
Volume : 88
Pages : 403-413
Catégorie(s)
#Genosol #INRAERésumé
Microcystins are cyclic heptapeptide hepatotoxins produced by aquatic cyanobacteria such as Microcystis aeruginosa. The wide occurrence of toxic microcystins in freshwater is a threat to the quality of water, agriculture, and human and animal health. There is actually little knowledge on the impact of microcystins on soil biomass. Here, an agricultural soil was daily irrigated with a cyanobacterial extract diluted at environmental concentrations of microcystin–leucine–arginine, from 0.005 to 0.1 mg equivalent MC-LR L−1, for 90 days. We measured soil enzymatic activities, nitrification potential activity of the soil microbial community, abundances of ammonia-oxidizing bacteria, and ammonia-oxidizing archaea amoA genes. Our results show an increase in potential nitrification for microcystin levels ranging between 0.005 and 0.02 mg eq. MC-LR L−1. Global enzymatic activities were unchanged. Abundances of total bacteria, archaea, and ammonia-oxidizing functional groups were not modified and could not explain the increase in nitrification.
Auteurs, date et publication :
Auteurs Sylvain Corbel , Noureddine Bouaïcha , Fabrice Martin-Laurent , Olivier Crouzet , Christian Mougin
Publication : Environmental Chemistry Letters
Date : 2015
Volume : 13
Issue : 4
Pages : 459-463
Catégorie(s)
#ANR-Citation #BiochemEnv #INRAERésumé
Soil is a primary resource used by mankind to ensure its needs mainly through agriculture. Its sustainability is regulated by the indigenous organisms it contains such as microorganisms. Current agricultural practices employ mixtures of pesticides to ensure the crops yield and can potentially impair these non-target organisms. However despite this environmental reality, studies dealing the susceptibility of microorganisms to pesticide mixtures are scarce. In this context, we designed a 3-month microcosm study to assess the ecotoxicity of realistic herbicide mixtures of formulated S-metolachlor (Dual Gold Safeneur®), mesotrione (Callisto®), and nicosulfuron (Milagro®) on the abundance, the diversity, and the activities of microorganisms from a “clay/organic matter-rich” soil, with a particular attention given to N-cycle communities. These communities appeared to be quite resistant to realistic mixtures even if transient effects occurred on the N-cycle-related communities with an increase of ammonification and an inhibition of nitrification as a short-term effect, followed by an increase of denitrification and an accumulation of nitrates. As nitrates are known to be highly leachable with a strong pollution potential, intensive studies should be carried out at field level to conclude on this potential accumulation and its consequences. Moreover, these data now need to be compared with other agricultural soils receiving these herbicide mixtures in order to bring general conclusion on such practices.
Auteurs, date et publication :
Auteurs Pierre Joly , Frédérique Bonnemoy , Pascale Besse-Hoggan , Fanny Perrière , Olivier Crouzet , Nathalie Cheviron , Clarisse Mallet
Publication : Water, air and soil pollution
Date : 2015
Volume : 226
Issue : 12
Pages : 413
Catégorie(s)
#BiochemEnv #Genosol #INRAERésumé
Land use practices alter the biomass and structure Of soil microbial communities. However, the impact of land management intensity on soil microbial diversity (i.e. richness and evenness) and consequences for functioning is still poorly understood. Here, we addressed this question by coupling molecular characterization of microbial diversity with measurements of carbon (C) mineralization in soils obtained from three locations across Europe, each representing a gradient of land management intensity under different soil and environmental conditions. Bacterial and fungal diversity were characterized by high throughput sequencing of ribosomal genes. Carbon cycling activities (i.e., mineralization of autochthonous soil organic matter, mineralization of allochthonous plant residues) were measured by quantifying C-12- and C-13-CO2 release after soils had been amended, or not, with C-13-labelled wheat residues. Variation partitioning analysis was used to rank biological and physicochemical soil parameters according to their relative contribution to these activities. Across all three locations, microbial diversity was greatest at intermediate levels of land use intensity, indicating that optimal management of soil microbial diversity might not be achieved under the least intensive agriculture. Microbial richness was the best predictor of the C-cycling activities, with bacterial and fungal richness explaining 32.2 and 17% of the intensity of autochthonous soil organic matter mineralization; and fungal richness explaining 77% of the intensity of wheat residues mineralization. Altogether, our results provide evidence that there is scope for improvement in soil management to enhance microbial biodiversity and optimize C transformations mediated by microbial communities in soil. (C) 2015 Elsevier Ltd. All rights reserved.
Auteurs, date et publication :
Auteurs Vincent Tardy , Ayme Spor , Olivier Mathieu , Jean Leveque , Sebastien Terrat , Pierre Plassart , Tiffanie Regnier , Richard D. Bardgett , Wim H. van der Putten , Pier Paolo Roggero , Giovanna Seddaiu , Simonetta Bagella , Philippe Lemanceau , Lionel Ranjard , Pierre-Alain Maron
Publication : Soil Biology and Biochemistry
Date : 2015
Volume : 90
Pages : 204-213
Catégorie(s)
#ANR-Citation #Genosol #INRAERésumé
Microcystins are cyclic heptapeptides hepatotoxins produced by aquatic cyanobacteria such as Microcystis aeruginosa. The wide occurrence of toxic microcystins in freshwater is a threat to water quality and health of living organisms. Here, we irrigated an agricultural soil daily with a cyanobacterial extract diluted at environmental concentrations of microcystin–leucine–arginine, from 0.005 to 0.1 mg equivalent MC-LR L−1, for 90 days. We analyzed the impact on the growth and physiology of tomato, Solanum lycopersicum cultivar MicroTom. Our results show a stimulation of the tomato plant development, in terms of inflorescence and blooming, after exposure to the lowest concentration, of 0.005 mg eq. MC-LR L−1, during the 40 first days post-germination. That effect was not apparently associated with physiological disturbances of the tomato plants.
Auteurs, date et publication :
Auteurs Sylvain Corbel , Noureddine Bouaïcha , Sylvie Nélieu , Christian Mougin
Publication : Environmental Chemistry Letters
Date : 2015
Volume : 13
Issue : 4
Pages : 447-452
Catégorie(s)
#ANR-Citation #BiochemEnv #INRAEAuteurs, date et publication :
Auteurs M. Christina , Nouvellon Y , Laclau J-P , Stape J- L , Campoe O-C , G. Le Maire
Publication : Canadian Journal of Forest Research
Date : 2025
Volume : 46
Issue : 3
Pages : 297-309
Catégorie(s)
#CIRAD #FORET Itatinga #INRAEAuteurs, date et publication :
Auteurs Florian Chabauty , Valérie Pot , Marjolaine Bourdat-Deschamps , Nathalie Bernet , Christophe Labat , Pierre Benoit
Publication : Environmental Science and Pollution Research
Date : 2025
Volume : 23
Issue : 7
Pages : 6907-6918
Catégorie(s)
#INRAE #PRO #PRO QualiAgroAuteurs, date et publication :
Auteurs LM Cardenas , AL Collins , JAJ Dungait , J Hawkins , Abad Chabbi , C Hawes
Publication : European Journal of Soil Science
Date : 2025
Volume : 67
Issue : 4
Pages : 359–359
Catégorie(s)
#ACBB #ACBB Lusignan #INRAERésumé
Dissolved organic matter in soil is a highly reactive pool of organic matter and is of great importance for biogeochemical cycles in soil. A better understanding of its dynamics relies on its molecular characterisation. Here, the molecular composition of water-extracted organic matter at elevated pressure and temperature (PH-WEOM) obtained from 120 Burgundy soils was investigated using high-field Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR MS). Unsupervised multivariate statistical analysis (UMSA) was used to retrieve classes of samples with specific molecular characteristics. Accordingly, van Krevelen diagram, Kendrick mass defect (KMD), as well as aromaticity index (AI) and aromaticity equivalent (Xc), were applied to present a pool of ubiquitous molecular formulas and to evaluate the PH-WEOM molecular heterogeneity in the sample set. Based on UMSA, the PH-WEOM from forest soils revealed a clearly distinct molecular composition, with major contributions from lignin- and tannin-like compounds, and with its aromaticity related to soil characteristics, especially the soil pH. No clear evidence of land-cover influence on the PH-WEOM molecular composition was found for cropland and grassland soils, but the role of pH was also identified for these samples, and agrees with molecular patterns attributed to microbial activity, with the presence of compounds with high H/C ratio. A group of samples from cropland soils developed on residual formations is characterised by a very specific molecular composition, rich in aliphatic organosulfur-like compounds, highlighting the importance of specific soil processes in the molecular composition of PH-WEOM. This work demonstrates the potential of FT-ICR MS to resolve the high chemical complexity of PH-WEOM in soils and the intricate influences of both biotic and abiotic environmental factors on the molecular composition of PH-WEOM in soils.
Auteurs, date et publication :
Auteurs Julien Guigue , Mourad Harir , Olivier Mathieu , Marianna Lucio , Lionel Ranjard , Jean Leveque , Philippe Schmitt-Kopplin
Publication : Biogeochemistry
Date : 2025
Volume : 128
Issue : 3
Pages : 307-326
Catégorie(s)
#ANR-Citation #Genosol #INRAEAuteurs, date et publication :
Auteurs T. Vanden Nest , G. Ruysschaert , B. Vandecasteele , S. Houot , S. Baken , E. Smolders , M. Cougnon , D. Reheul , R. Merckx
Publication : Agriculture, Ecosystems and Environment
Date : 2025
Volume : 216
Pages : 23-33