Search results for "Soil"
showing 10 items of 3493 documents
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 …
Microbial Community Structure and Density Under Different Tree Species in an Acid Forest Soil (Morvan, France)
2005
Overexploitation of forests to increase wood production has led to the replacement of native forest by large areas of monospecific tree plantations. In the present study, the effects of different monospecific tree cover plantations on density and composition of the indigenous soil microbial community are described. The experimental site of "Breuil-Chenue" in the Morvan (France) was the site of a comparison of a similar mineral soil under Norway spruce (Picea abies), Douglas fir (Pseudotuga menziesii), oak (Quercus sessiflora), and native forest [mixed stand dominated by oak and beech (Fagus sylvatica)]. Sampling was performed during winter (February) at three depths (0-5, 5-10, and 10-15 cm…
Variations du stockage et de la dynamique de la matière organique en fonction de l'utilisation des sols dans les savanes du Rift éthiopien.
2007
13 pages; International audience
Effect of rhizosphère bacteria and endomycorrhizal fungi on the growth of Christmas rose (Helleborus niger L.)
2010
International audience; Micropropagated and vegetative (by rhizome cuttings) propagated plants of Christmas rose ( Helleborus niger L.) were tested for their responses to the inoculation with microorganisms in order to optimize root growth and development. In our experiment, plants were inoculated with arbuscular endomycorrhizal fungi or/and Agrobacterium radiobacter . The investigation indicated that inoculation with A. radiobacter had significantly positive effect on growth and development of plants multiplicated by in vitro techniques as compared to the dual inoculation. This study indicates that, biotization can be beneficial to plant growth in in vitro plant production systems but inoc…
Concepts and methods to assess phytosanitary quality of soils
2005
Chapitre 9.4 : Plant-microbe interactions and soil quality; International audience
Are soils suppressive to fungal diseases the sources of biocontrol agents ?
2014
Soils suppressive to soil-borne diseases are defined by a low disease incidence in spite of the presence of a virulent pathogen and a susceptible plant. In many cases, the inhibition of the disease development relies on the activity of the resident soil microbiome. Suppressiveness can be transmitted to conducive soil by mixing a small amount of suppressive soil into the conducive one. To identify microbial taxons linked to the suppressive phenotype of soils, culture independent-based methods have been employed to analyze and compare microbial diversities in two different soils suppressive (respectively conducive) to either Fusarium wilt of flax or Rhizoctonia diseases of sugar beet. Metagen…
Mapping intra-plot topsoil diversity of Burgundy vineyards (Aloxe- Corton, France) from very high spatial resolution (VHSR) images
2012
International audience; In this work, we present a method based on very high spatial resolution (VHSR) aerial images acquired in the visible domain and that map soil surface diversity at the hillslope scale with a spatial resolution of a few centimeters. This method combines aerial VHSR image classification with local soil sampling. Principal component analysis (PCA) and non-supervised classification was performed on image characteristics to define soil surface characteristic classes (SSC). Then soil surface mapping was combined with soil surface descriptions and soil profiles to define soil types by physical and chemical characteristics.
Mapping field-scale spatial distribution patterns of size and activity of the denitrifier community
2008
International audience
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…
A tale of two stories from the underground: soil microbial diversity and N cycling
2016
International audience; Dr. Laurent Philippot is Director of Research at the French Institute for Agricultural Research (INRA) and is leading a research group at the department of Agroecology in Dijon. He did a sabbatical at Georgia Tech in Atlanta and at the Swedish University of Agricultural Science (SLU) in Uppsala in 2000 and 2009, respectively. His research focuses on bridging microbial community ecology, microbial processes and ecosystem functioning using microbial guilds involved in nitrogen cycling and greenhouse gas. He is serving as Senior Editor of The ISME Journal and as editorial board member for FEMS Microbiology Ecology, Applied and Environmental Microbiology and Frontiers in…