Search results for "soil"

The adaptation of cornflower in different compartments of the agricultural landscape

2015

International audience; Agrosystems are among habitats most affected by the decline of biodiversity. This decline isrelated to the intensification of agricultural practices carried out since the 50s (simplified rotations,fertilizer and pesticide use; ...). The study of the weed flora shows still less developed plantcommunities. Currently, there is evidence of the regression of the weed flora and especiallyspecies such as cornflower (Cyanus segetum. L). In western Europe, cornflower seems to bepresent in the field only. In our investigation, we tried to determine the factors that influence thepresence of cornflower in the different compartments of a field and its border.

Aptitude à la levée et à l'installation d'adventices dans des bandes enherbées. Quelles sont les réelles potentialités d'installation d'espèces adven…

2010

International audience

Diversifying crop rotations with perennial forage crops: potential benefits for weed management & farmland biodiversity

2010

Crop rotation may be used to prevent the continuous selection of weed species adapted to one crop type. However, today’s crop rotations are often very short and simple. We studied the impacts of introducing perennial forage crops into cereal-based crop rotations on weed vegetation. Large-scale weed surveys in 632 fields in western France suggested that the weed species composition varied most strongly between perennial alfalfa forage crops and six annual crops[1]. Comparisons of wheat fields before, during, and after perennial alfalfa suggested that weed communities vary in a cyclic way during such crop rotations. This may be beneficial for weed management (suppression of weed species probl…

Mating system adaptation in populations of Centaurea cyanus L.

2010

International audience; Since the 50s, the agriculture intensification in Western Europe resulted in landscape homogenizationand reduction of habitat connectivity, which in turn caused a widespread decline of farmland biological diversity.Centaurea cyanus is one of the declining “segetal species”. It is an annual and insect-pollinatedspecies with a self-incompatibility system. When the populations are small and fragmented, they mayextinct if the incompatibility system cannot evolve towards a compatibility system. A coexistence ofmixed mating system is also possible in a population.In our study, we examined the ability of C. cyanus to produce seeds by autogamy. For this purpose,three conditi…

Trois jours au cœur du COLUMA 2016

2012

Lutte contre les mauvaises herbes en France, dix lustres en lumière : Analyse de 50 ans d’usage des herbicides tirée d’une « mine »

2010

A core microbiota of plant and earthworm interaction? Phylogenetic and functional aspects

2017

International audience; The core microbiota concept has been proposed to describe the subset of a microbiota (e.g. the rhizosphere microbial community) associated with a given host (e.g. a plant) going beyond macroenvironment differences (e.g. soil type), and characterized by taxonomic markers (e.g. 16S rRNA gene sequences). Its existence has been questioned by geographical studies, showing the overruling soil type effect in shaping microbial communities. As far as biotic determinants are concerned, several “hosts” or macroorganisms are impacting a given habitat and its specific microbial community. In soils, there is an overlap between the so-called rhizosphere and the drilosphere, defined…

Connecting soil biodiversity to functions and ecosystem services: presentation of case studies and of the EU FP7 project EcoFINDERS

2012

Soils provide essential ecosystem services such as primary production, regulation of biogeochemical cycles and their consequences on climate, water filtration, resistance to pests and diseases, and regulation of above-ground biodiversity. These services result from functions supported by soil organisms. Their abundance, diversity and activities vary according to environmental factors and Human activities. Despite progress made over the last decade in assessing soil biodiversity, the huge reservoir of biodiversity represented by soils remains superficially explored as do the relations between soil biodiversity and functioning. This lack of knowledge is related to the small size of most organ…

Impact of anaerobic digestates on microbial communities of agricultural soils

2022

Anaerobic digestion of organic waste is considered as a key process to produce renewable energy to meet the growing sustainable energy demand. The residues of this anaerobic digestion, called digestates, can be used in agriculture as soil amendments and improve crop yields. However, the effect of digestates on soil biota, especially on microorganisms is still debated and needs to be better documented before their use at large scale in agricultural fields. The objective of the present thesis was to assess the effect of digestates on soil microbial community in different geographical and pedoclimatic contexts on the French territory. This thesis is divided in two parts. The first part takes p…

Response of soil bacterial and hppd communities to tembotrione herbicide

2022

Herbicides used in agriculture aim to prevent weed growth but are known to end up in contactwith soil microorganisms, thus defined as non-target organisms. Tembotrione, a recentlymarketed β-triketone herbicide, is known to inhibit the 4-HydroxyPhenylPyruvateDioxygenase(4-HPPD) in weeds. This enzyme is also found in numerous soil microorganisms, such as somePGPR and symbiotic bacteria, that play a key role in maintenance of ecosystem services.In this study, one of the major concerns is to assess whether tembotrione could have toxiceffects on soil microorganisms and could disturb soil microbial community dynamic andstructure. To investigate the possible impacts of this herbicide on these comm…