Search results for "community"
showing 10 items of 2132 documents
Comparison of different tillage systems in organic farming : effect of soil structure and organic matter repartition on soil micro-organisms and thei…
2009
Over the last decades, the surface traditionally ploughed has tended to decrease and replaced by shallow working tillage techniques without soil inversion, i.e., no tillage or reduced tillage with tines or discs. These techniques were mostly developed in conventional farming systems but nowadays they are also developed in organic farming systems. Nevertheless, these tillage techniques could generate crop nutrients deficiencies and a deterioration of soil structure, especially during the first years of their application. As the use of synthetic fertilizers is forbidden in organic farming, a decrease of the soil fertility could be very detrimental for crop growth. Indeed, soil micro-organisms…
Caractérisation des communautés microbiennes dans les technosols construits pour la restauration des friches industrielles
2012
Increasing soil degradation and its consequences on overall ecosystem services urge for restoration strategies. Construction of Technosols through assemblage of treated soil and industrial wastes is an innovative technology for the restoration of polluted land and re-use of industrial by-products. Recent studies have evidenced that Technosols could support ecosystemic services such as primary production but the knowledge about other soil functions, such as biogeochemical cycling, is limited. Due to the significant contribution of microbial communities to soil functioning, this PhD work was carried out to study the effect of the type of Technosol on microbial communities with a focus on func…
SOIL MICROBIOLOGICAL QUALITY: STATE OF THE ART AND IMPORTANCE OF MICROBIAL COMMUNITIES FOR FRENCH AGRICULTURAL SOILS
2022
Soils are one of the major reservoirs of biological diversity on our planet, hosting a huge diversity of microorganisms. Numerous studies have demonstrated the role of microbial diversity in soil functions, such as nutrient cycling or pathogen management. Given the key role of soil microorganisms in the regulation of soil ecosystem functions, the environmental factors driving soil microbial diversity need to be understood. In France, we have the opportunity to benefit from a national soil survey (called the French Soil Quality Monitoring Network), which represents one of the most extensive and without a priori soil sampling survey available to date. Through several funded projects, we were …
Evolution des problèmes malherbologiques à l’adoption du semis direct sous couvert
2019
Le semis direct sous couvert regroupe un ensemble de pratiques appliquées simultanément en vue de répondre à trois principes : réduction totale du travail du sol, couverture optimale des sols et diversification de la succession culturale. Cette approche représente, en France, une stratégie innovante qui semble convaincre de plus en plus d’agriculteurs. En se privant du travail du sol, la gestion des adventices en semis direct sous couvert devient plus complexe, ce qui limite l’adoption généralisée du semis direct sous couvert. Afin d’éclairer les problèmes malherbologiques rencontrés en semis direct sous couvert, un questionnaire en ligne à destination des agriculteurs a été diffusée en Fra…
Mapping spatial patterns of denitrifiers for bridging community ecology and microbial processes along environmental gradients
2009
International audience; While there is ample evidence that microbial processes can exhibit large variations at a field scale, very little is known about the spatial distribution of the communities mediating these processes. The objective of this study was to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N-cycling, in a grassland field subjected to different cattle grazing regimes. We used geostatistical modeling to map the distribution of size and activity of the denitrifier community in the pasture. Size of the denitrifier community was estimated by PCR quantification of the denitrification gene copy numbers while its activity w…
Deciphering biotic interactions and their role in soil microbial community assembly
2021
National audience; Soil microbial communities play key roles in ecosystem functioning. Yet, little is known aboutthe importance of microbe-microbe interactions in soil microbial community assembly andfunctions. To address this knowledge gap, the objective of my thesis is to assess the role ofinteractions between micro-organisms in soil microbial communities. For this purpose, we willmanipulate the interactions between microorganisms within complex soil microbialcommunities by (i) removing different members of the soil community, (ii) adding microbialtaxa to the soil community and (iii) increasing the physical distance between members of thesoil community. How shifts in microbial interaction…
Bridging microbial community ecology and nitrogen cycling in soil
2011
Pas de résumé
Assemblage, structuration et évolution des communautés microbiennes terrestres
2020
Mapping, understanding and predicting soil microbial diversity across France
2018
International audience; Microorganisms are extremely abundant and diverse in soils. Their huge diversity is central in soil functioning regarding the diversity of functions it supports (mineralization, detoxification, stability of soil…) and is more and more studied, especially in a context of increasing pressure on soil resources. Conversely to macroorganisms whose distribution on a wide scale has been studied for over a century, spatial scaling and determinism distribution of soil microorganisms on nationwide scale still needs to be documented, notably to decipher the environmental filters shaping these communities. communities were investigated at the scale of France to characterize thei…