Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The inclusion of cover crops in agricultural production systems has received attention for the ability to improve the multifunctionality of the soil. In order to improve soil structure and soil physical-hydric properties, especially soil water infiltration, the objective of this study was: (a) to evaluate the effect of different species of winter cover crops on soil physical properties and (b) to verify the relationship between punctual methods for the evaluation of water infiltration in the soil and the infiltration of water with natural rainfall on plot scale. For the first study the systems studied were: oat and vetch (AE) consortium, oat and turnip (AN), spontaneous vegetation (VE) and bare soil (SD). Soil samples with undisturbed structure were collected in the layers of 0 - 0,05; 0,05 - 0,1; 0,1 - 0,2 and 0,2 - 0,3 m to measure bulk density (DS), total porosity (Pt), macroporosity (Mac), microporosity (Mic), saturated soil hydraulic conductivity (Ksat) and permeability to air (Ka). Soil aggregation was also evaluated in the layers of 0 - 0.05 and 0.5 - 0.1 m. Soil water infiltration was determined by the concentric double ring method. For the second study, three treatments were used in the first study to determine the rate of stable infiltration of soil water (TIE) by the Cornell infiltrometer, double ring infiltrometer and infiltration in natural rainfall events. The results indicate that after the cultivation of winter cover crops, there are no changes in the physical properties evaluated, but there is evidence of improved water infiltration in the soil and the continuity and pore diameter in the treatments with cover crops. The TIE determined by the Cornell infiltrometer and double ring infiltrometer method is overestimated from 1.8 to 2.2 times that of natural rainfall. / A inclusão de plantas de cobertura em sistemas de produção agrícola tem recebido atenção pela habilidade de melhorar a multifuncionalidade do solo. Com vistas a melhoria da estrutura do solo e de propriedades físico-hídricas do solo, principalmente da infiltração de água no solo, objetivou-se com este trabalho: (a) avaliar o efeito de diferentes espécies de plantas de cobertura de inverno em propriedades físico-hídricas do solo e (b) verificar a relação entre métodos pontuais de avaliação da infiltração de água no solo com a infiltração de água com chuva natural em escala de parcela. Para o primeiro estudo os sistemas estudados foram: consorciação de aveia e ervilhaca (AE), consorciação de aveia e nabo (AN), vegetação espontânea (VE) e solo desnudo (SD). Amostras de solo com estrutura preservada foram coletadas nas camadas de 0 - 0,05; 0,05 - 0,1; 0,1 - 0,2; 0,2 - 0,3 m para avaliações da densidade do solo (Ds), porosidade total (Pt), macroporosidade (Mac), microporosidade (Mic), condutividade hidráulica do solo saturado (Ksat) e permeabilidade ao ar (Ka). Avaliou-se também a agregação do solo nas camadas de 0 - 0,05 e 0,5 - 0,1 m. A infiltração de água no solo foi determinada pelo método de duplo anel concêntrico. Para o segundo estudo foram utilizados três tratamentos do primeiro estudo para determinação da taxa de infiltração estável de água no solo (TIE) pelos métodos do infiltrômetro de Cornell, duplo anel concêntrico e a infiltração em eventos de chuva natural. Os resultados indicam que após um cultivo de plantas de cobertura de inverno ainda não são observadas alterações nas propriedades físicas avaliadas, porém há indícios de melhoria da infiltração de água no solo e na continuidade e diâmetro de poros nos tratamentos com plantas de cobertura. A TIE determinada pelo método de duplo anel concêntrico e infiltrômetro de Cornell é superestimada de 1,8 a 2,2 vezes em relação a determinada com chuva natural.

Le bois est en général étudié comme un matériau orthotrope et homogène, mais en réalité il existe des gradients de propriétés mécaniques et physiques dans chaque direction. En effet, le bois est constitué d’une alternance de cernes annuels de croissance constitués de bois d’été, de printemps et de transition. Ces cernes sont plus réguliers dans la plupart des résineux que dans les feuillus. Dans le présent document, on s’intéresse à l’étude et à l’identification des propriétés de diffusion hydrique d’un résineux à l’échelle du cerne, le sapin blanc du Massif Central. Une telle étude nécessite l’utilisation d’une technique de mesure de champ sans contact, ici la méthode de la grille. Cette dernière offre la possibilité d’observer l’hétérogénéité du bois à l’échelle du cerne avec des champs de déformations. Elle permet donc d’obtenir la réponse sous sollicitations hydriques des bois d’été et de printemps. Cette technique de mesure est couplée à une méthode d’identification inverse des paramètres de comportement hydrique que nous avons mise en place. Elle permet d’obtenir les coefficients de diffusion des bois d’été et de printemps dans la direction tangentielle de diffusion, ainsi que leurs coefficients d’expansion hydrique dans la direction radiale à partir des cartes de déformations obtenues par la méthode de la grille. La méthode de la grille est également utilisée pour l’étude du comportement du bois sous environnement constant ou variable, et sous contrainte mécanique de compression radiale. Des méthodes d’identification sont également proposées afin de déterminer les propriétés mécaniques selon la direction radiale du bois à l’échelle du cerne, ceci à partir des cartes de déformation. / Wood is generally studied as an orthotropic and homogeneous material, but in reality there are gradients of mechanical and physical properties in each direction. Indeed, wood consists of summer and spring woods which manifest annual growth rings. These latter are more regular in most of softwoods than in hardwoods. In this paper, we are interested in studying and identifying the properties of a resinous under water diffusion, namely the white fir of the Massif Central. This study requires the use of a contacless full-field measurement technique. The grid method is used here. This latter offers the opportunity to observe the heterogeneity of wood at the ring scale through the strain fields. It thus provides the response of latewood and earlywood under water stress. This measurement technique is coupled with an inverse method to identify the water behavior parameters. This inverse method provides latewood and earlywood diffusion coefficients along the tangential diffusion direction, as well as their coefficients of expansion in the radial direction from the strain maps. The grid method is also used to study the behavior of wood under constant or variable environment when it is subjected to radial compression. Some identification methods are also proposed to determine from the deformation maps the mechanical properties along the radial direction of wood at the ring scale.

Un dispositif en sol nu comprenant trois parcelles (90 m²) et six cases lysimétriques (4 m²) instrumentées a permis d’étudier l’influence d’apports répétés d’une boue de station d’épuration (BOUE) et de la même boue compostée avec des déchets verts (DVB) sur (i) les modifications des propriétés physico-chimiques et hydriques du sol ; (ii) le transport des ions bromures ; (iii) la dynamique de minéralisation du carbone et de l’azote organiques dans le sol. Finalement, le calage des paramètres hydrodynamiques et de décomposition de la matière organique dans le sol, propres à chaque horizon des profils de sols instrumentés, a permis une description satisfaisante de la dynamique hydrique et du transport des ions bromures et nitrates observés expérimentalement. Ces résultats aideront à l’adaptation de scénarios agronomiques sur le long terme pour répondre plus efficacement aux problématiques liées aux nouvelles exigences de recyclage des déchets et de protection de l’environnement. / An instrumented experimental bare soil site including three plots (90 m²) and six lysimeters (4 m²) has enabled to study the influence of repeated sewage sludge (SS) applications, as well as the same sewage sludge composted with green waste (SGW), on (i) the soil physicochemical and hydric properties ; (ii) the transport of bromide ions ; (iii) the organic carbon and nitrogen mineralization dynamics in soil. Finally, fitting the governing hydraulic parameters and the organic matter decomposition parameters in each soil horizon allowed a satisfying description of the experimentally observed water and bromide and nitrate ions transport in soil. These results will help conceive long-term agronomical scenarios aimed at providing more efficient answers to the new requirements of environmental protection and waste recycling policies.