Search results for "azot"
showing 10 items of 137 documents
Modélisation de la répartition des assimilats au sein du système racinaire chez le pois de printemps (Pisum sativum)
2014
leguminous plant, can fix atmospheric nitrogen through symbiosis with symbiotic bacteria of the genus Rhizobium. Yet the sensitivity of symbiotic N fixation to biotics and abiotics stresses leads to a significant yield and protein rate variability compared with cereals. A better understanding of C and N partitioning between roots and shoots according to the mode of N nutrition seems necessary to identify levers of yield stabilisation. In this context, the model PeaNod developed within INRA Dijon Ecophysiology team combines an architectural model of pea with an source-sink approach. The main objective of this work was to study the impact of competition between nodules and roots on roots arch…
Atténuation des émissions par les sols du gaz à effet de serre N2O, grâce à l’utilisation d’additifs ou de microorganismes, tous d’origine naturelle
2021
National audience; Les sols agricoles sont la principale source du gaz à effet de serre (GES) N2O (protoxyded’azote). D’un point de vue environnemental ce gaz est impliqué à la fois dans l’effet de serreadditionnel et la destruction de la couche d’ozone stratosphérique. Le pouvoir de réchauffementglobal (PRG) du N2O sur une durée de 100 ans est 265 fois supérieur à celui du dioxyde decarbone (CO2). La durée de vie du protoxyde d’azote dans l’atmosphère est d’environ 120 ans.Ainsi, il apparait comme le 3ème gaz participant au réchauffement climatique d’origineanthropique, après le CO2 et le CH4. Les sols peuvent fonctionner comme source mais aussicomme puits de N2O, par l’intermédiaire de mé…
Mise en évidence du rôle de la diversité dans la dynamique des communautés d'adventices et des interactions adventices/cultures
2020
The main challenge of 21st century agriculture is to provide sufficient food for a growing to identify cropping systems which maintain crop productivity, minimize reliance on synthetic herbicides and nitrogen fertilizers, and promote weed diversity. We hypothesized that cropping system diversification, either at the annual scale through the introduction of cover crops, or at the plurennial scale through a diversification of the crop sequence and associated weed management tools, could be a viable means to reach these objectives. More specifically, we hypothesized that cropping system diversification could (i) contain weed abundance and thereby, allow a reduction of herbicide use and an incr…
Typology of exogenous organic matters based on chemical and biochemical composition to predict potential nitrogen mineralization
2010
Our aim was to develop a typology predicting potential N availability of exogenous organic matters (EOMs) in soil based on their chemical characteristics. A database of 273 EOMs was constructed including analytical data of biochemical fractionation, organic C and N, and results of N mineralization during incubation of soil–EOM mixtures in controlled conditions. Multiple factor analysis and hierarchical classification were performed to gather EOMs with similar composition and N mineralization behavior. A typology was then defined using composition criteria to predict potential N mineralization. Six classes of EOM potential N mineralization in soil were defined, from high potential N minerali…
Fixation symbiotique et effet précédent : toutes les légumineuses ne se valent pas
2018
National audience; [pas de résumé]
Symbiose fixatrice de l'azote des légumineuses : principes de fonctionnement, impacts agronomiques et environnementaux
2017
National audience
Impacts of Integrated Weed management in cropping systems on N2O emissions from soils
2014
International audience
Characterization and role of nitric oxide production in Arabidopsis thaliana defense responses induced by oligogalacturonides
2011
Nitric oxide (NO) regulates a wide range of plant processes from development toenvironmental adaptation. In this study, NO production and its effects were investigated in aplant-pathogen context. The production of NO following Arabidopsis treatment witholigogalacturonides (OGs), an endogenous elicitor of plant defense, was assessed using the NOsensitive probe 4, 5-diamino fluorescein diacetate. Pharmacological and genetic approaches wereused to analyze NO enzymatic sources and its role in the Arabidopsis thaliana /Botrytis cinereainteraction. We showed that NO production involves both a L-arginine- and a nitrate reductase(NR)-pathways. OGs-induced NO production was Ca2+-dependent and modula…
Study of nitrogen requirements of non-Saccharomyces yeasts during winemaking : impact on sequential fermentations
2019
Study of the interaction between the non-Saccharomyces yeast and Saccharomyces cerevisiae. This study aims to describe changes in the flavor profile of the wine on one hand and reducing percentage of alcohol on the other hand. For this, control of non-Saccharomyces yeast is required. Thus, the main aromatic molecules must be measured according to the conditions of cultures (pure culture - sequential culture) and their effects on the organoleptic properties will be evaluated. In parallel, their sugar, nitrogen, oxygen and vitamins requirements will be determined to decrease the percentage of alcohol in the wine.
Ecology of N2O reducing bacteria in arable soils
2016
Nitrous oxide (N2O) is an important greenhouse gas (GHG) and the main ozone depleting substance. Agricultural soils are the main anthropogenic-induced source of this GHG. The concentration of N2O in the atmosphere is steadily increasing, but we still lack knowledge on the factors controlling its production and consumption in soils. The reduction of N2O to N2 by microorganisms harboring the N2O reductase gene (nosZ) is the only known biological process able to consume this GHG. Recent studies revealed a previously unknown clade of N2O-reducers which was shown to be important to the N2O sink capacity of soils. This thesis seeks to gain a greater understanding on the ecology of N2O-reducers in…