Tesi sul tema "Sols – Composition"
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Shahnavaz, Bahar. "Communautés bactériennes de sols alpins et filtres environnementaux". Grenoble 1, 2009. http://www.theses.fr/2009GRE10331.
Testo completoBacteria play a key role in biogeochemical cycles. While the effect of winter snow cover in function and composition of soil bacterial communities has been reported, the effect of spatiotemporal variation of snow cover remains to be studied. In this study, we characterised the spatio-temporal dynamics of bacterial communities from two sites at the extremes of a snow cover gradient. We used molecular (SSCP and cloning/sequencing) and traditional (bacterial isolation by culture) approaches. The presented results show that the overall bacterial diversity, composition and phylogenetic structure are strongly related to snow cover duration. Moreover, these effects are also detectable during the plant productive season. The biotic and abiotic factors (i. E. Plant senescence and soil pH) play an essential role leading to the clustering of certain bacterial clades (Acidobacteria, Actinobacteria, α- and β-Proteobacteria). During the plant productive season, the bacterial clades are overdispersed. The preset study shows that, at a fine taxonomic level, the temporal variation is more important than the change over space. At higher taxonomic levels (i. E. Sub-phylum), the space are more important than temporal variations. Only a minor fraction of the total bacterial diversity is cultivable, and may bacterial groups be overrepresented in culture plates. This study provides new insights in role of snow cover in bacterial communities’ distribution and role of winter. This study may be useful in predicting of bacterial behaviour in nutrient cycle in a context of global warming
Al, Majou Hassan. "Etude et prédiction des propriétés de rétention en eau des sols : prise en compte de la composition et de l'état structural du sol". Orléans, 2008. https://tel.archives-ouvertes.fr/tel-00286622.
Testo completoLesturgez, Grégory. "Densification des sols sableux sous culture mécanisée : cas du Nord-Est Thaïlandais". Nancy 1, 2005. http://docnum.univ-lorraine.fr/public/SCD_T_2005_0008_LESTURGEZ.pdf.
Testo completoThe thesis focuses on sandy soils of Northeast Thailand. A compact and resistant layer developed at low depth is a main constraint for agriculture. The thesis follows a sequence of studies that investigates (i) the physical properties of these soils in various situation natural or cultivated, (ii) the main mechanisms explaining the different physical states recorded and (iii) the research of methods for rehabilitation of damaged soils. Results highlighted the aeolian origin of the soils. This origin gives them a striking textural homogeneity and unique mechanical characteristics. Very sensitive to compaction, they collapse at low water content and under low mechanical pressure. Conventional tillage practices are not suitable as they induce structural instability. However alternative techniques as slotting or biological drilling are efficient
Hracherrass, Ahmed. "Etude des peuplements de Teline linifolia (L. ) Webb. Et Berth. En forêt de la Mamora (Maroc) : organisation spatiale, biométrie, biomasse, productivité et composition phytochimique". Aix-Marseille 3, 1993. http://www.theses.fr/1993AIX30055.
Testo completoBOUABDALLAN, EL-HADI. "La vegetation steppique sur sols sales des hautes-plaines sud-algeroises. Composition, structure et production". Paris 11, 1992. http://www.theses.fr/1992PA112472.
Testo completoSalvador-Blanes, Sébastien. "Déterminisme de la distribution spatiale des éléments majeurs et traces dans les sols en contexte métamorphique : plateau d'Aigurande, nord du Massif central, France". Tours, 2002. http://www.theses.fr/2002TOUR4014.
Testo completoBalasoiu, Florina Cristina. "Influence de la composition des sols sur la spéciation et la toxicité du chrome, du cuivre et de l'arsenic dans des sols contaminés par du CCA". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ65556.pdf.
Testo completoBen, Hassine Habib. "Etude de l'évolution des propriétés chimiques et physico-hydriques des principaux types de sols céréaliers du Nord-Ouest tunisien : effets sur les productions céréalières". Aix-Marseille 1, 2002. http://www.theses.fr/2002AIX11038.
Testo completoKedi, Atolé Brice. "Fonctionnement des phosphatases dans les sols tropicaux : influence de la composition organo-minérale sur l'expression de l'activité enzymatique". Thesis, Montpellier, SupAgro, 2011. http://www.theses.fr/2011NSAM0049/document.
Testo completoThe role of catalytic activity of fungal phosphatases in the improvement of the phosphorus nutrition cannot be reliably predicted without taking into account the factors which influence their behaviour in the soil. The objective of this thesis was to study various factors which could influence the effectiveness of ectomycorrhizal fungal phosphatases in soils. Adsorption and the activity in the adsorbed state of phosphatases produced by Suillus collinitus and Hebeloma cylindrosporum were studied in contact with several fractions of various tropical soils. The persistence of the activity of these enzymes immobilized on the soils was also studied. These phosphatases showed a diversity of affinity for soil colloids, due to their origin and their characteristics. Moreover, no relation was found between adsorption and the resulting catalytic activity; there was generally no loss of activity in an adsorbed state. One of the enzymes which underwent rapid degradation in solution was protected by the presence of ferrallitic soils but not by the vertisols. These fungic phosphatase samples were purified and partially characterized. The fractions of S. collinitus phosphatases retained on hydrophobic chromatography column showed enhanced activity in contact with mineral clays with respect to solution. The hypothesis of dimeerisation on the clay surfaces was advanced to explain the unexpected enhancement of catalytic activity in an adsorbed state of the purified fractions
Angeli, Nicolas Dambrine Etienne. "Evolution de la composition chimique des ruisseaux vosgiens Analyse rétrospective et effet d'un amendement calco-magnésien /". [S.l.] : [s.n.], 2006. http://www.scd.uhp-nancy.fr/docnum/SCD_T_2006_0096_ANGELI.pdf.
Testo completoSterckeman, Thibault. "Caractérisation du fond géochimique en éléments en traces dans les sols issus de roches sédimentaires du Nord de la France". Vandoeuvre-les-Nancy, INPL, 2004. http://www.theses.fr/2004INPL022N.
Testo completoSurface and deeper horizons developed in 22 parent materials were sampledin the agricultural and forest soils of Northern France. Total contents of 18 trace elements and two major elements (AI, Fe) were determined in 758 horizon samples, together with the pedological characteristics. Ln the deep horizons, the positive linear correlations of the less mobile trace elements (Bi, Co, Cr, Cu, ln, Ni, Pb, Sn, TI, V, Zn) contents with lutum(particles < 2μm), AI and Fe contents suggest that trace elements are closely associated to alumino-silicates and iron oxi-hydroxides of the finest solid phase. These correlations are close and are common to the deeper horizons of ail the parent materials, whatever their age and type. The processes of the sedimentary rock genesis, including ancient pedogenesis, did not cause any major segregation of the less mobile elements. The mobile elements (As, Cd, Hg, Mn, Mo, Sb Se) show less close relationship with the minerai phase, except Cd and As which seem particularly associated to Mn and Fe respectively. Mercury, Mn and Se show strong links with the organic matter in the deep horizons. Soit parent materials often show an enrichment with the mobile elements. Most of the calcareous rocks are enriched with Cd. Enrichments with ail trace elements, except with Co, Cr and Ni, were found in the surface horizons
Bianchini, Ange. "Contribution à la valorisation d'une plante aromatique de Corse, Helichrysum italicum (Roth) G. Don subsp. Italicum : composition chimique de l'huile essentielle, composition inorganique du végétal et des sols". Corte, 2002. http://www.theses.fr/2002CORT2008.
Testo completoMorin, Nathalie. "Les Microcodium : architecture, structure et composition, comparaison avec les racines calcifiées". Montpellier 2, 1993. http://www.theses.fr/1993MON20025.
Testo completoOberle, Sylviane. "Le drainage des prairies permanentes en Lorraine : étude des motivations des agriculteurs, conséquences sur la composition floristique et sur la physionomie". Vandoeuvre-les-Nancy, INPL, 1987. http://www.theses.fr/1987NAN10423.
Testo completoNguyen, Minh Thu. "Modélisation hydromécanique des ouvrages de stockage des déchets radioactifs avec prise en compte de l'endommagement et du transfert de l'hydrogène". Rennes, INSA, 2008. http://www.theses.fr/2008ISAR0006.
Testo completoThe argilite of Callovo Oxfordien is a sedimentary rock formed in sea water which is made up mainly of quartz, carbonates, argillaceous minerals and various minerals. This heterogeneity of constitution associated with a very low porosity of about 12% confers on argillite a specific behaviour. Indeed this specific behaviour is induced by: (i) of the mechanisms on a microscopic scale of type forces contact with friction for solid minerals quartz and calcite, of repulsion and viscosity for argillaceous minerals and (ii) of the strong interactions between the solid and fluid phases. Thus the conceptual model of the short-term behaviour is proposed while being based on five hydraulic characteristics: (1) two surfaces of loads of the type Drescher & Mroz, associated a pressure of consolidation of 200MPa and a cohesion on healthy argillite, (2) the creation of an anisotropic damage induced by the strains in extension under states of stresses deviators, (3) a distribution of the stress between the solid phases and fluids which uses the coefficient of Biot depend on the maximum damage, (4) a concept of the effective stress for the partially saturated states by calling upon an equivalent pore pressure which depends on the capillary pressure and an average value of the damage and (5) the absence of volumic strains of swelling on healthy argillite. The plastic strain-rates are specified by the non_associative flow rule with the plastic loading surface F and the plastic potential G. On the other hand the behaviour differed from argillite utilizes many mechanisms, chemical, physicochemical and a slip on the scale of the argillaceous layers inducing of the phenomena of viscosity. In the absence of a consensus related mainly to the experimental difficulties and being the subject of current research of the geotechnical grouping of research, one thus proposed a simplified macroscopic model. The introduction of a phase gas into the computer code of finite elements CLEO allowing simulating the transfer of hydrogen. The dealt with problems relate to a standard work cell in direct contact with argillite (without bentonite barrier) with a production of H2 variable in time. These modelling are proposed without heating effect. Lastly, simulations of the saturation of an embanked gallery have the aim of studying the basic phenomena brought into play at the time of the resaturation of a gallery. One proposed a hierarchisation in the processes of simulation by adopting the development of the two conceptual models, one bearing on physics and the other on the numerical aspects. The numerical conceptual model milked space-time introduction of the constituent voluminal elements
Gobé, Valérie. "Matière organique complexe du sol ; structure et rôle dans les processus d'humification du carbone xénobiotique". Poitiers, 1998. http://www.theses.fr/1998POIT2316.
Testo completoErktan, Amandine. "Interactions entre composition fonctionnelle de communautés végétales et formation des sols sans des lits de ravines en cours de restauration écologique". Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00949148.
Testo completoBekmirzaev, Gulom. "Relations eau et cultures de légumes : effet des sols salins et conditions de sècheresse sur la croissance, composition minérale et photosynthèse". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10010/document.
Testo completoConventional techniques used to control the soil salinization process - soil leaching or fertilization enhancing - contribute highly to soil and aquifers contamination; on the other hand, the use of salt tolerant species will be very useful to the plants, but does not solve the problem of soil or groundwater contamination. Hence, the only way to control the salinization process to maintain the sustainability of landscapes and agricultural fields is to combat the salinization problems with environmentally safe and clean techniques. One of these new techniques is the use of salt removing species. In order to study the potential capacity to remove soil salts, two horticultural species Portulaca oleracea and Tetragonia tetragonioides, and the salt sensitive crop lettuce (Lactuca Sativa L) were evaluated for their efficiency to remove salts from sandy soil. Plants were analysed relatively to total growth and mineral composition of the leaves and soil. According to the results, it was seen that T. tetragonioides is the best salt removing species and complementary, it has other benefits, which are as follows: 1) high biomass production; 2) several harvests; 3) high content of minerals; 4) horticultural importance; 5) easy multiplication; 6) easy crop management; 7) tolerance to drought conditions; 8) soil erosion control. P. oleracea is a high drought tolerant species, followed by T. tetragonioides. As concluding remarks, it was shown that this new technique to control salinity is a powerful and environmental clean tool to maintain the sustainability of the landscape and of the irrigated areas
Angeli, Nicolas. "Evolution de la composition chimique des ruisseaux vosgiens : Analyse rétrospective et effet d'un amendement calco-magnésien". Nancy 1, 2006. http://docnum.univ-lorraine.fr/public/SCD_T_2006_0096_ANGELI.pdf.
Testo completoOur work is based on (1) a functional analysis of a long term in the chemical composition of streams since fifty-years, (2) an experimental liming of catchments. The historical analysis showed an acidification and a continuous demineralization of water draining sandstone since fifty years. The acidity and the mineralization of streams draining granites rich on weatherable minerals have decreased since thirty years. In the area covered by granites rich in Na plagioclase, which is drained by many acid streams, mineralization has decreased since twenty years and Al concentration have decreased since ten years, without pH changes. The experimental input of dolomite and dolomitic limestone, gypsum and KCl has caused a sudden and durable increase in Ca, Mg and pH in the stream of granitic catchment riche in sodium plagioclase. The dynamic of chloride showed a rapid contribution of soil waters to the humid area and stream, while a small fraction has infiltrated deeper into the soil. On sandstone, except a direct effect during the flood following the liming, the increase of concentrations was very small. The majority of chloride, Ca and Mg are infiltrated deeper into the permeable sandy soils, without contributing directly to the stream flow. Hydrologic, isotopic, chemical arguments suggest that the mean residence time of water and mineral elements in catchment is of several decades This work supports the scientific material for a reasoned politic of acidity correction of stream water in the Vosges mountains
Travers, Isabelle. "Influence des conditions pédoclimatiques du terroir sur le comportement du pommier et la composition des pommes à cidre dans le Pays d'Auge". Caen, 2004. http://www.theses.fr/2004CAEN2018.
Testo completoAubert, Maëlle. "Caractérisation de l’état de surface des sols nus agricoles par imagerie radar TerraSAR-X". Electronic Thesis or Diss., Paris, AgroParisTech, 2012. http://www.theses.fr/2012AGPT0047.
Testo completoIn the context of sustainable development, soil and water resources management is a key issue from not only the environmental point of view, but also from a socioeconomic perspective. Soil moisture, roughness, composition, and slaking crusts are some key variables used to understand and model natural hazards, such as erosion, drought and floods. For agricultural bare soils (most subject to runoff), numerous studies have already shown the potential of C-band RADAR data for the mapping of soil moisture and roughness. However, the application of these methods in operational settings remained limited.In this context, the first objective of this thesis was to analyse the sensitivity of X-band TerraSAR-X sensors to soil surface characteristics (SSC) at high spatial and temporal resolutions. Different TerraSAR-X configurations were evaluated and results were used to define the optimal instrumental configuration for the characterization of each SSC parameter. The comparison of TerraSAR-X sensor sensitivity with equivalent levels recorded with the C-band sensor showed that the TerraSAR-X sensor is undoubtedly the most suitable of the two when estimating and mapping soil moisture at a fine scale (50 m²).The second objective of this work was to develop a method to estimate and map soil moisture levels of agricultural bare soil. To achieve this goal, methods that are commonly used to retrieve soil moisture from C-band, have been tested on X-band data. The accuracy of soil moisture estimations using an empirical algorithm was determined, and validated successfully over numerous study sites. A mapping process based uniquely on TerraSAR-X data, both for bare soil detection and for the estimation of soil moisture content, was developed. This innovative chain of « automatic and autonomous» mapping processing steps should enable the utilization of TerraSAR-X data for the mapping of soil moisture levels in operational conditions
Al, Majou Hassan. "Étude et prédiction des propriétés de rétention en eau des sols : Prise en compte de la composition et de l'état structural du sol". Phd thesis, Université d'Orléans, 2008. http://tel.archives-ouvertes.fr/tel-00286622.
Testo completoKouakoua, Ernest. "La matière organique et la stabilité structurale d'horizons de surface de sols ferrallitiques argileux : effet du mode de gestion des terres". Nancy 1, 1998. http://www.theses.fr/1998NAN10016.
Testo completoBetoulle, Jean-Luc. "Variations spatiales de la production primaire et des apports au sol en éléments minéraux dans cinq faciès d'une mangrove en Guyane française". Toulouse 3, 1998. http://www.theses.fr/1998TOU30288.
Testo completoAugustin, Marie-Monique. "Etude de l'influence de certains facteurs sur les composés phénoliques du raisin et du vin". Bordeaux 2, 1986. http://www.theses.fr/1986BOR20013.
Testo completoCooke, Joshua. "Étude et prédiction de l’impact des paramètres de digestion anaérobie sur la composition des digestats et leur effet sur la stabilité structurale des sols". Electronic Thesis or Diss., Rennes, Agrocampus Ouest, 2023. http://www.theses.fr/2023NSARB370.
Testo completoDemand for renewable energy is driving rapid growth in the agricultural anaerobic digestion (AD) sector. Digestates, by-products from AD, are used as organic fertilisers and soil amendments. Yet, our understanding of the effects of the wide array of digestates produced on soil biological, chemical and physical processes is limited. Our objective was to investigate the impact of digestate application on soil physical health, through study of the aggregate stability (AS), a key indicator of soil resistance to crust formation and erosion. Laboratory testing of digestates from agricultural AD sites revealed that their short-term impact on soil AS may vary considerably. A proposed typology of impact categorises the likely effect of different digestates according to AD process parameters, as an aid to agronomic decision-making and AD plant conception. We determined digestate characteristics linked to changes in soil AS, andconsidered the mechanisms involved, including direct interactions between soil and mineral or organic components, and indirect stimulation of microorganisms by "bioaccessible" organic matter. While the short-term effects of digestate on silt soil AS in field trials were limited compared to climateinduced variations, there were no negative effects. Digestate application may even lead to a very gradual improvement in AS of silt loam soils over time. However, certain mineral-rich digestates can induce transient negative effects on AS in other soil contexts. These findings provide insight into the short-termimpacts of digestate on soil processes leading to aggregate stabilisation. Nevertheless, going forward, an integrated approach accounting for many issues surrounding digestate use in agriculture is required to achieve sustainable soil management
Mijno, Violaine. "Modifications de la composition de déchets métallifères, miniers et industriels, stabilisés par liants hydrauliques et soumis à des tests de lixiviation". Limoges, 2007. https://aurore.unilim.fr/theses/nxfile/default/6f5b340b-3fef-467e-af61-14e7675f4edc/blobholder:0/2007LIMO4014.pdf.
Testo completoCement-based stabilization/solidification (s/s) is a widely used treatment process for industrial and mining waste. S/s used physical and chemical properties of biding agent, to decrease pollutants leaching toward environment. Two cement matrices are used (Portland cement only or with fly ash addition). Pollutants bearing phases are sulphurs and iron oxides, for mining waste. In industrial waste, copper is incorporated in the C-S-H (1,2 %). The samples are subjected to three leaching tests to simulate the storage conditions and to understand contaminant immobilization. Exposure to the mining acid drainage shows the succession of several leaching front for the industrial waste with a particular zone of accumulation of contaminants. Cement matrix of mining waste samples is preferentially consumed compared to the mineral phases. The exchanges with an acid rainwater show a weak leach of contaminants (< 15 Cu ppm). For an in-depth storage with groundwater contact, a carbonation zone is formed decreasing the leaching process of copper
Demon, Michel. "Influence des facteurs climatiques et des constituants du sol sur la dynamique de l'atrazine". Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL092N.
Testo completoMachinet, Gaylord Erwan. "Utilisation de la variabilité génétique du maïs pour évaluer le rôle de la qualité chimique des racines sur le processus de décomposition dans les sols". Reims, 2009. http://theses.univ-reims.fr/exl-doc/GED00001012.pdf.
Testo completoSince several years, plant roots aroused a new interest due to the environmental concern of their C input and storage in soils after decomposition subsequent to plant death or harvest. To better understand the role of the chemical quality of roots on their decomposition in soils and associated C dynamics, sixteen maize roots of hybrids and of brown-midrib mutants were used. These genotypes were earlier characterized by variations in the cell wall quality of above ground organs with respect to forage digestibility. The variations of root chemical quality were observed mainly on the cell wall polymers content and composition (polysaccharides and lignin). They translated into large differences in the kinetics of C mineralization during decomposition. The characterization of initial cell wall quality of the 16 roots together with the detailed study of the changes in cell wall quality during decomposition for 4 contrasted genotypes evidenced the role of soluble C on the short term, lignin fraction of the longer term, and the role of the organization of the cell walls in decomposition. .
Céspedes, Payret Carlos. "Dinámica de la materia orgánica y de algunos parámetros fisicoquímicos en Molisoles, en la conversión de una pradera a cultivo forestal en la región de Piedras Coloradas-Algorta (URUGUAY)". Toulouse, INPT, 2007. https://hal.science/tel-04595831.
Testo completoAfforestation of prairie regions has rapidly reached, as a recent world-wide policy, countries like Uruguay, but little is known about the effects of eucalyptus plantation on soil organic matter (SOM) dynamics. In order to evaluate their possible effects in a prairie soil, some soil parameters were compared, before and after forestation. The zone of study was located 200 km from the Rio Uruguay mouth (Piedras Coloradas-Algorta) in a 1200-mm temperate gently undulated sandy lowland dominated by Mollisols with an herbaceous vegetation of photosynthetic pathway C4 type. The study included two stages; in the first one, a 25-year old C3 type cultivation (Eucalyptus grandis) and eight soil parameters (organic matter, pH, cation exchange capacity (CIC) Ca2+, Mg2+, Na+, free and amorphous Fe) are considered. The soil samples were taken also by horizons (A and B). The data obtained was statistically evaluated by t-tests and analysis of variance (ANOVA). In the second stage the cultivation time and parcel number were increased and the sampling was made on the less resilient (0-20cm) depths. Here, the key parameters were restricted to C (TOC and δ13C) pH and apparent density. From the overall 30 years data set it arises that there is an effective loss of total organic carbon (TOC) in soils cultivated with eucalyptus and that the lower mean residence time of C derived from the eucalyptus is responsive of the total soil carbon decline. The TOC decline was related with the age of the plantation for most of previous land uses and with a change in other parameters (pH, apparent density, CIC, Ca2+, Mg2+, Fe3+ and 1:1/2:1 clay balance). Eucalyptus affects the C balance of soil and it is explained by an increase of its turnover. The soil C sequestration in afforestation projects appears questionable in Uruguayan mollisols
Clément, Éric. "Modélisation de l'influence du relief et de l'occupation des sols sur la composition des eaux de rivière et des sédiments de rivière : application à la prospection géochimique". Nice, 1990. http://www.theses.fr/1990NICE4430.
Testo completoPiton, Gabin. "Résilience des écosystèmes prairiaux aux stress climatiques selon l'intensité de gestion. Une approche par le concept de trait fonctionnel microbien Using proxies of microbial community‐weighted means traits to explain the cascading effect of management intensity, soil and plant traits on ecosystem resilience in mountain grasslands The resilience of soil microbial communities to climate change-induced rain regimes differs between conventional and ecological-intensive managed soils across European agroecosystems Implementing ecoenzymes in the trait framework bring new insights on the microbial communitiy composition control on ecosystem functioning". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAV070.
Testo completoIn the current context of climate change, associated with increases of climate extremes frequency and intensity, understanding the ecosystem response to climate variability is a central challenge in ecology. Soil microbial communities control most ecosystem processes driving energy and nutrients fluxes. In the context of agriculture management, an important question is to understand the influence of farming practices on soil microbial communities and their capacity to maintain ecosystem functioning under climate change. Ecological-intensive agriculture has been recently proposed as an approach integrating ecological processes in management strategies to optimise agroecosystems functioning and resilience to climate change. Functional ecology might be relevant to address these challenges associated with climate change and ecological-intensification of agriculture.In this PhD thesis, I used the functional trait framework to grassland ecosystems to address how different modalities of management intensity (extensive, conventional-intensive, ecological-intensive management) influence: 1) functional parameters of soil microbial communities; 2) the capacity of these soil microbial communities to maintain ecosystem functioning during and after climatic stresses (Resilience). During my PhD, three experiments have been conducted using different degrees of control of management factors and simulating different kind of climatic stresses, with different durations. Based on grassland agroecosystems in three countries across Europe (France, Switzerland, Portugal), results from the first two experiments of this PhD showed that ecological-intensive management select soil microbial communities with a lower capacity to maintain microbial ecosystem properties during stresses (resistance) but with higher capacity to recover compared with soil microbial communities of soils under conventional-intensive management. Moreover, another study showed that ecological-intensive management promotes beneficial proteolytic soil microbial communities for plant nitrogen uptake under climate change-induced rain regimes. Plant functional traits assessment suggest this management effect on microbial communities composition and resilience to be explained by higher litter phosphorous content in ecological-intensive systems. Indeed, this plant functional trait affect microbial traits, favouring copiotrophic microbial community characterized by a lower nitrogen:phosphorous ratio of their biomass and a lower investment in extracellular enzymes production, two traits decreasing stress resistance but increasing recovery capacities. Thereby, these two experiments stress the relevance of plant traits management to control soil microbial traits and the resilience of soil microbial communities to climate changes. A third experiment tested specifically the impact of a mineral fertilisation event on the resilience of soil microbial communities to different climatic stresses. Results clearly demonstrated that fertilization modify soil microbial community composition and soil microbial traits and decrease ecosystem stability under climatic stresses.Implementing an approach based on the microbial functional trait concept, this thesis brings new insights on the effects of management intensity on grassland ecosystem resilience to climatic stress
Ercolani, Christian. "Reconstruction des régimes d'altération actuels et passés à partir des isotopes du bore dans les sédiments de rivière". Electronic Thesis or Diss., Strasbourg, 2018. http://www.theses.fr/2018STRAH008.
Testo completoThis thesis has the following objectives: 1) To better understand how boron isotopes in modern fluvial sediments record the weathering regime at the catchment scale. 2) To better understand how the weathering “signal” carried by river sediments is transferred from source areas to the depositional environment. 3) To determine if boron isotopes in sediment deposits (paleochannels) can be used to reconstruct paleo-weathering and paleo-environmental conditions and reveal how continental weathering at large (production and sediment transport) responds to climatic variability over the last glacial-interglacial cycle (last 100 ka). These objectives were addressed by studying fluvial material from the Gandak (Himalayas) and Murrumbidgee (NSW, Australia) Rivers and fluvial sediment deposits from the Riverine Plain (Murrumbidgee catchment, Australia). Knowledge of the parameters that control boron isotope fractionation of river sediment during formation and transport was first gained in the modern systems and then applied to ancient paleochannel deposits
Humbert, Guillaume. "Déterminisme hydro-climatique de la composition et du transfert des matières organiques dissoutes dans un bassin versant agricole". Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S151/document.
Testo completoThe role of dissolved organic matter (DOM) as carbon storage in mineral soil horizons and the impacts of DOM on aquatic ecosystems, either as a source of nutrients, or a vector of pollutants, raise the need to understand its origin, and the mechanisms linked to its transport from soils to stream. This work aims to characterize the temporal and spatial dynamics of the amount and the quality of DOM in soil and stream water, and to identify the controlling factors. It is based on the Kervidy-Naizin catchment of 5 km² (Morbihan ; Environment Research Observatory AgrHyS). This site benefits from 13 years of daily stream dissolved organic carbon (DOC) concentrations and high frequency of hydro-climatic parameters (discharge, groundwater table depths, and meteorological variables). DOM concentration and composition of soil water under contrasted land uses (cropland, grassland, or woodland) and stream water were assessed at least fortnightly during 2 hydrological cycles. A comprehensive and consistent pattern of hydrological processes that control the DOM exports, their changes in time (by providing an objective definition of hydrological seasons), and the changes of their relative importance according to the climatic context of the year was proposed. The exports of DOM produced in the soils during summer control the intra-annual decrease of stream DOC concentrations. This suggests a compensatory mechanism whereby increased winter exports can balance the summer production of DOM resulting in a relatively uniform mean annual DOC concentration. The DOM composition of soil and stream water was determined by fluorescence spectroscopy combined with PARAFAC (parallel factor analysis) modeling built from excitation-emission matrices. Exports from agricultural sources characterized by low aromatic, protein-like, microbial-derived DOM were reported. This DOM is transported to the stream seasonally during inter-storm periods of very wet winters, by rising of the water table in arable hillslope soils, and occasionally in spring, during storm events that follow the animal manure application on catchment soils. The spatial organization of temporal dynamics of the DOM concentration and composition of soil waters suggested that they were controlled by combined effects of hydrology, soil properties and topography. DOM with fewer aromatic moieties is preferentially exported from organo-mineral horizons of hillslope soils. DOM loss from mineral soil horizons are partially balanced by DOM inputs from upper soils. The onset of reducing conditions in downslope soils produces aromatic DOM that is transported to the stream only during storm events. Hence, DOM from agricultural soils is more susceptible being transport to stream due to its composition and its location within the catchment. The question of the fate of these DOM in aquatic ecosystems is raised
Bedel, Léa. "Approche isotopique pour tracer la dynamique des éléments dans deux écosystèmes forestiers du plateau lorrain, développés sur des sols polycycliques". Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0074/document.
Testo completoTwo forest ecosystems in Lorraine, France (Clermont-en-Argonne CA and Azerailles AZ) developed on polycyclic soils have a complex functioning due to the presence of two different materials within the soil profile, leading to an abrupt disruption in soil texture. Indeed, they have low exchangeable Ca and Mg stocks in the silty soil upper layers (with a greater poverty in CA than in AZ), and very large stocks in deep clayey layers. These differences in upper soil fertility between the studied sites can be partly explained by a weaker aggregation in CA than in AZ (with aggregates poor in organic matter and clays). The CA soil then holds less nutrients than AZ one, despite higher atmospheric inputs and more rapid mineralization of litter. The richness of the deep soil layers in both sites, cannot be explained by the two conventional inputs i.e. atmospheric deposition and mineral weathering, A third un-expected source was identify using Sr, Ca and Mg isotopes, i.e. a mineralized groundwater table, which allows the CEC recharging of the deep clay layers by simple ion exchange when its invades the subsoil during the winter period. Trees have developed an uptake strategy into these Ca and Mg rich clay layer, to overcome the relative poverty of the upper soil layers. However the consequence of the Mg limititation of the soil upper layers in CA is visible through the increase in the internal Mg-translocation before leaf senescence
Joimel, Sophie. "Biodiversité et caractéristiques physico-chimiques des sols de jardins associatifs urbains français". Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0037/document.
Testo completoCommunity gardens (e.g. allotments, shared gardens) currently experience a renewed interest among the French and are often associated with many functions and services within urban ecosystems (vegetable supply, biodiversity). As such, garden soils are a major concern and their characteristics (physico-chemical as well as biological ones) need to be better understood. What connection is there between the functional quality of garden soils and the alteration of their physico-chemical characteristics by gardening practices? What influence do these properties in garden soils have on functional and taxonomic biodiversity? In order to answer these questions, investigations were conducted in vegetable gardens chosen as representative of the ecosystemic variability within French territory. On one hand work was done on the topsoil's agronomical properties and toxicity. On the other hand these soils were characterised using several biological indicators, such as vegetal species and soil microarthropods. With the help of several databases, we were able to place these garden soils among other french topsoils by comparing them to other land uses. Despite having high total metallic contents garden soils show an undeniable physico-chemical fertility, and support a high level of soil biodiversity. In contrast, an increasing plant biotic homogenisation can be observed within cities. Indeed, there is a selection of species with traits that are particularly adapted to urban environments. In conclusion, even though garden soils exist in a highly anthropised urban context they are not degraded ecosystems, but rather a precious resource
FILLION, GUIGUES NATHALIE. "Contribution de la matiere organique dissoute a la composition chimique des eaux de surface. Mesure de l'alcalinite et de l'acidite organique, application aux precipitations atmospheriques et aux solutions de sols". Université Louis Pasteur (Strasbourg) (1971-2008), 1998. http://www.theses.fr/1998STR13059.
Testo completoZamora-Ledezma, Ezequiel. "Evidences for an indirect effect of root functional traits and plant composition on soil microbial activities in Mediterranean rangelands : a spatial and temporal approach". Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20176/document.
Testo completoIt is increasingly recognized that the understanding of ecosystem functioning requires a combined above- and belowground approach, because of the importance of feedbacks between plants and soil. Plant community structure may affect soil functioning by altering the quantity and the quality of resources entering the soil. Abiotic controls on soil microbial processes are well documented, but potential effects of plant composition and root traits are poorly understood. The study was conducted in Mediterranean grasslands located in southern France. We selected 12 contrasting communities along a gradient of soil resource availability, which is mainly driven by soil texture. The aims of the thesis were to evaluate: i) the response of plant composition and leaf and root traits measured at the community level along the soil gradient and across seasons, ii) their effect on three soil microbial processes involved in carbon (C) and nitrogen (N) cycling, i.e. substrate-induced respiration (SIR), nitrifying (NEA) and denitrifying enzyme activities (DEA). In sandy soils (unproductive plots) plant communities had a conservation strategy at the leaf level and an acquisitive strategy at the root level suggesting a strong plasticity of root traits in response to resource limitation; rates of SIR and NEA were higher. Opposite pattern was observed in clay productive soils. DEA did not vary along the gradient. We did not find evidence of a species richness, evenness, or plant biomass effect on SIR and NEA. However, we demonstrated that they were strongly influenced by plant functional composition (abundance of graminoids), and particularly by root traits. Our most innovative finding evidences that NEA, and to a lesser extent SIR, were positively correlated with root nitrogen (N) concentration and negatively correlated with C/Ncom, whereas analogous leaf traits have only minor effect on microbial activities. Our results suggested that the chemical quality of roots is the main driver of soil activities and this was confirmed across the seasons. We highlight strong seasonal variations in plant community composition, root traits and soil microbial activity, except DEA. Seasonal variations in root traits were interpreted as a relative change in the proportion of young versus old roots and suggested an asynchrony between above– and belowground growth. We showed for the first time evidences that in natural conditions, seasonal changes in root functional traits could be implicated in driving NEA and SIR. This result demonstrates the need to further develop studies allowing a better understanding of the role of root traits as soil functioning drivers
Koundouras, Stéfanos. "Incidence des sols et du climat de la région viticole de Némée (Grèce) sur le régime hydrique et la physiologie du cépage agiorgitiko (Saint-Georges) : relations avec la maturation du raisin et la composition des vins". Bordeaux 2, 1999. http://www.theses.fr/1999BOR20665.
Testo completoAubert, Maelle. "Caractérisation de l'état de surface des sols nus agricoles par imagerie radar TerraSAR-X". Phd thesis, AgroParisTech, 2012. http://tel.archives-ouvertes.fr/tel-00764268.
Testo completoSaenger, Anaïs. "Caractérisation et stabilité de la matière organique du sol en contexte montagnard calcaire : proposition d'indicateurs pour le suivi de la qualité des sols à l'échelle du paysage". Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENS010/document.
Testo completoMountain soils are major reservoirs of carbon (C), potentially vulnerable to climate and land use changes that affect them significantly. However, the great variability of these soils, their limited accessibility and the lack of appropriate measurement tools restrict our knowledge. Today, our comprehension of the biogeochemistry of mountain soils remains very incomplete regarding stocks, chemistry and reactivity of soil organic carbon (SOC). Yet this information is necessary to understand the evolution of soil carbon in the current context of global change. The objectives of this work were (i) to gain a better understanding of the nature, stability and vulnerability of SOC in a mosaic of ecosystems in a calcareous massif in the Alps (Vercors massif), (ii) to search for fast and reliable characterization tools, suitable for the study and monitoring of COS at the landscape scale, and (iii) to propose indicators for the assessment and monitoring of soil quality in mountain regions. As a first step, we tested the application of Rock-Eval pyrolysis for the study of COS at large-scale on a set of ecosystem units. Then, we compared the Rock-Eval approach to two conventional techniques for soil organic matter (SOM) study: the particle-size fractionation of SOM, and the mid-infrared spectroscopy. These coupled analytical approaches allowed us to quantify C stocks across the study area, and explain the stability and the vulnerability of COS at various angles. Factors responsible for the patterns observed in the different eco-units are discussed. This work also confirmed the relevance of the Rock-Eval tool to achieve our previous objectives. Biological approaches allowed us to assess the significance of microbial pool in these soils. Finally, indices assessing the status of SOM (SOC storage, soil fertility, vulnerability COS) were proposed and constituted interesting management tools for decision-makers
Violette, Aurélie. "Processus et bilans d'altérations en milieu tropical (bassin versant de Mule Hole, Inde du sud) : sensibilité à la composition minéralogique et au climat". Toulouse 3, 2010. http://thesesups.ups-tlse.fr/1199/.
Testo completoThe objective of this thesis is to improve our understanding of the chemical weathering processes and of the control factors at a small experimental watershed scale in the Tropics (Mule Hole, South India). Relying on the numerical modelling method, it focuses particularly on the sensitivity to the mineralogy and climate. The first part of this work concerns the mineralogical and chemical descriptions of the soils (chromic luvisol, vertisol) and the bedrock (gneiss). The second part deals with the coupled modelling between a geochemical and a hydrological model. On the first hand, current processes at play in the catchment are investigated. The model is calibrated with both stream and groundwater measured chemical compositions. The results show that the chemical weathering fluxes are mainly supplied by the dissolution of authigenic smectites in soils (5 vol. %) and not by the dissolution of the primary minerals. On the second hand, sensitivity tests to the mineralogical composition and climate are performed
Perrin, Anne-Sophie. "Rôle des fertilisants azotés dans l'érosion chimique des bassins versants carbonatées : implication dans la consommation de CO2 et la composition chimique des eaux de surface". Toulouse 3, 2008. http://thesesups.ups-tlse.fr/817/.
Testo completoNitrogenous fertilizers are a major contributor of acidity to soils and carbonate bedrocks, as a result of their high reactivity, are the main buffers through mineral weathering reactions. This perturbation of natural carbonate weathering processes is susceptible to modify the carbon budget of the weathering loop. Different approaches, from soil and small catchment experiments in the south-west of France (Gascogne area) to global scale estimations allowed us to better constrain the impact of these modifications on the quality of riverine water and on the global carbon budget. Carbonate weathering processes induced by nitrogenous fertilizers would decrease the proportion of alkalinity (and thus of carbon) in relation to calcium and magnesium ions by a minimum of respectively 5,7 to 13,4% and 1,6 to 3,8% of the CO2 naturally consumed by carbonate weathering in France and on a global scale. This decrease represents 6 to 15% of the CO2 consumed by silicate weathering on a global scale. Experimentations on soil columns showed that nitrification processes of ammonium ions increase cations fluxes in drainage soil solutions and lead to direct CO2 emissions to the atmosphere. Elements and carbonate weathering budgets, measured from intensive surveys of elements fluxes in two small agricultural catchments (the Montoussé and the Hay catchments) highlighted the role of hydrology, vegetation and secondary precipitation of calcite in the relative loss of CO2 consumption by carbonate weathering in agricultural areas
Delavat, François. "Composition et fonctionnement d'une communauté microbienne au sein d'un drainage minier acide : approches culturales et fonctionnelles". Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00797981.
Testo completoRiofrio, Dillon Gabriela. "Évolution de l'acidité et de la disponiblité en azote des sols forestiers français au cours du 20ème siècle : une approche spatio-temporelle et multi-échelle basée sur le caractère bio-indicateur de la flore". Thesis, Paris, AgroParisTech, 2013. http://www.theses.fr/2013AGPT0042/document.
Testo completoHuman activities have, over the last century, strongly influenced the cycles controlling the levels of acidity and nitrogen availability in nature. Acidifying and eutrophying deposition lead to a change in environmental conditions and particularly to sensitive changes in plant communities' composition.The objective of this Ph.D work is to reconstruct the spatiotemporal evolution of the acidity and nitrogen availability in French forest soils over the 20th century using the bioindicator character of plants, into local and global scales. The use of plants as bioindicator seeks to mitigate the lack of direct measurements of soil conditions and atmospheric deposition, over a wide spatiotemporal extent. First, changes in bioindicated soil pH (indicator of acidity conditions) and C:N (indicator of nitrogen availability status) were computed from approximately 100 000 temporary floristic plots carried out throughout France from 1910 to 2010. They were analyzed using an innovative method of spatiotemporal comparison, where acidic and nonacidic forest areas and coniferous and broadleaved forests were differentiated. Secondly, and always from the bioindicator character of plants, changes in soil conditions between 1972 and 2011 across Villey forest as well as floristic changes they induce related with other environmental changes were analyzed.At the global level, we observed acidification in acidic forest areas (-0.34 pH units on average) and in nonacidic areas (-0.19 pH units on average), respectively, until 1984 and 1997. We demonstrated for the first time (to our knowledge) a cessation of acidification of forest soils and even a decrease in acidity in nonacidic forest areas, as wella as a time lag for acidification between acidic and nonacidic areas. This trend is consistent with the trend of acidifying deposition in France since the early 20th century. Spatially, our results confirm the temporal trends, show a regional geographic pattern of acidification (mainly observed in nonacidic areas), and highlight the high spatial variability of soil pH changes. Concerning the evolution of nitrogen availability conditions, we observed an unexpected decrease in available nitrogen until 1984 and 1997, respectively, in coniferous (+0.79 C:N units on average) and broadleaved forests (+0.74 C:N units on average). A trend to eutrophisation of forest soils was then observed in coniferous and broadleaved forests since 1997 (-0.10 and -0.16 C:N units on average, respectively). This trend is not consistent with the trend of nitrogen atmospheric deposition in France. ”Last and final summary in the thesis.”
Silva, Laura Fernanda Simões da. "Atributos físicos e micromorfológicos da estrutura de um Latossolo Vermelho distroférrico típico submetido ao manejo agrícola". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256856.
Testo completoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
Made available in DSpace on 2018-08-19T11:10:54Z (GMT). No. of bitstreams: 1 Silva_LauraFernandaSimoesda_D.pdf: 13977443 bytes, checksum: 9d8e76e6eed7bedacb43c17037906997 (MD5) Previous issue date: 2011
Resumo: A estrutura é um dos atributos mais importantes do solo sob o ponto de vista agrícola, sendo não somente influenciada pelo clima, atividade biológica e práticas de manejo, mas também por forças de natureza mecânica e físico-química. Nesse contexto, o trabalho teve por objetivo geral avaliar a influência do uso e do manejo agrícola sobre a qualidade estrutural de um LATOSSOLO VERMELHO Distroférrico típico (Rhodic Hapludox). A avaliação foi realizada com base em indicadores físicos tradicionais e empregando técnicas de análise micromorfológica e micromorfométrica. A pesquisa foi desenvolvida em Campinas, SP, em duas parcelas experimentais cultivadas com milho, uma sob Sistema Plantio Direto (SPD) e outra sob Sistema Convencional (SC)... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: Soil structure is one of its most important attribute concerning the agricultural point of view, being influenced not only by climate, biological activity and management practices, but also by mechanical and physical- chemical forces acting in it. In this context, the main purpose of this work was to evaluate the influence of agricultural use and management on the structural quality of a Rhodic Hapludox. The evaluation was carried out considering traditional physical indicators and also by employing micromorphological and micromorphometrical techniques. The study was developed at Campinas, SP, in an experimental area with maize under no-till system (NT) and conventional system (CS)¿ Note: The complete abstract is available with the full electronic digital thesis or dissertations
Doutorado
Agua e Solo
Doutor em Engenharia Agrícola
Stimpson, Michael. "Composition". Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284571.
Testo completoPédrot, Mathieu. "Colloïdes et compositions élémentaires des solutions de sols". Phd thesis, Université Rennes 1, 2009. http://tel.archives-ouvertes.fr/tel-00533848.
Testo completoVarella, Hubert Vincent. "Inversion d’un modèle de culture pour estimer spatialement les propriétés des sols et améliorer la prédiction de variables agro-environnementales". Thesis, Avignon, 2009. http://www.theses.fr/2009AVIG0638/document.
Testo completoDynamic crop models are very useful to predict the behavior of crops in their environment and are widely used in a lot of agro-environmental work. These models have many parameters and their spatial application require a good knowledge of these parameters,especially of the soil parameters. These parameters can be estimated from soil analysis at different points but this is very costly and requires a lot of experimental work. Nevertheless,observations on crops provided by new techniques like remote sensing or yield monitoring, is a possibility for estimating soil parameters through the inversion of crop models. In my work, the STICS crop model is studied for the wheat and the sugar beet and it includes more than 200 parameters. After a previous work based on a large experimental database for calibrate parameters related to the characteristics of the crop, I started my study with a global sensitivity analysis of the observed variables (leaf area index LAI and absorbed nitrogen QN provided by remote sensing data, and yield at harvest provided by yield monitoring) to the soil parameters, in order to determine which of them have to be estimated. This study was made in different climatic and agronomic conditions and it reveals that 7 soil parameters (4 related to the water and 3 related to the nitrogen) have a clearly influence on the variance of the observed variables and have to be therefore estimated. For estimating these 7 soil parameters, I chose a Bayesian data assimilation method (because I have prior information on these parameters) named Importance Sampling by using observations, on wheat and sugar beet crop, of LAI and QN at various dates and yield at harvest acquired on different climatic and agronomic conditions. The quality of parameter estimation is then determined by comparing the result of parameter estimation with only prio rinformation and the result with the posterior information provided by the Bayesian data assimilation method. The result of the parameter estimation show that the whole set of parameter has a better quality of estimation when observations on sugar beet are assimilated. At the same time, global sensitivity analysis of the observed variables to the 7 soil parameters have been performed, allowing me to build a criterion based on sensitivity indices (provided by the global sensitivity analysis) able to rank the parameters with respect to their quality of estimate. This criterion constitutes an interesting tool for determining which parameters it is possible to estimate to reduce probably the uncertainties on the predictions. The prediction of the crop behaviour when estimating the soil parameters is then studied. Indeed, the quality of prediction of agro-environmental variables of the STICS crop model (yield, protein of the grain and nitrogen balance at harvest) is determined by comparing the result of the prediction using the prior information on the parameters and the result using the posterior information. As for the estimation of soil parameters, the prediction of the variable is made on different climatic and agronomic conditions. According to the result of parameter estimation, assimilating observations on sugar beet lead to a better quality ofprediction of the variables than observations on wheat. It was also shown that the number ofcrop seasons observed and the number of observations improve the quality of the prediction
Brazier, Jean-Michel. "Rôle des phases minérales des sols en tant que réservoirs de nutriments : approche expérimentale (abiotique), en milieu naturel et multi-isotopique (isotopes stables Ca-Sr)". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAH005/document.
Testo completoThis PhD thesis examined the mechanisms of storage and release, from and elementary and isotopically point of view, of calcium (Ca) and strontium (Sr) onto or into mineral phases commonly encountered within soils (primary minerals, clay minerals, oxy-hydroxides, pedogenic carbonate). A robust δ88Sr measurements method had to be developed in the laboratory and validated by the measurement of international reference materials, mostly never measured in the literature. The results of this work show that Ca adsorption onto phyllosilicate minerals generates a quantifiable isotopic fractionation by preferential uptake of the light isotope (40Ca) under our experimental conditions when the minerals have a significant structural charge and specific surface area and/or an interlayer space open to hydrated cations adsorption. A study on rhizoliths in natural environment has also highlighted that the combination of Ca and Sr isotopes allows an effective tracing of sources and mechanisms in the problematic related to the storage of these two elements within soils