References of "Javaux, Mathieu"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailPlant Water Uptake in Drying Soils
Lobet, Guillaume ULg; Couvreur, Valentin; Meunier, Félicien et al

in Plant Physiology (2014), in press

Detailed reference viewed: 12 (2 ULg)
Full Text
Peer Reviewed
See detailRoot water uptake and water flow in the soil-root domain
Lobet, Guillaume ULg; Hachez, Charles; Chaumont, François et al

in Amram, Eshel; Beeckman, Tom (Eds.) Plant Roots. The Hidden Half (2013)

Detailed reference viewed: 55 (8 ULg)
Full Text
Peer Reviewed
See detailWater stress drastically reduces root growth and inulin yield in Cichorium intybus (var. sativum) independently of photosynthesis
Vandoorne, Bertrand; Mathieu, Anne-Sophie; Van den Ende, Wim et al

in Journal of Experimental Botany (2012), 63(12), 4359-4373

Root chicory (Cichorium intybus var. sativum) is a cash crop cultivated for inulin production in Western Europe. This plant could be exposed to severe water stress during the three last months of their ... [more ▼]

Root chicory (Cichorium intybus var. sativum) is a cash crop cultivated for inulin production in Western Europe. This plant could be exposed to severe water stress during the three last months of their six months growing period. The aim of this study was to quantify the effect of a progressive decline in water availability on plant growth, photosynthesis and sugar metabolism and to determine its impact on inulin production. Water stress drastically decreased root fresh and dry weight, leaf number, total leaf area and stomatal conductance. Stressed plants, however, increased their water use efficiency, decreased the shoot to root ratio and lowered their osmotic potential through soluble sugar accumulation. Despite a decrease in photosynthetic pigments, the light phase of the photosynthesis remained unaffected under water stress. Water stress increased sucrose phosphate synthase (SPS) activity in the leaves, but not in the roots. Water stress inhibited sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan:fructan 1 fructosyltransferase (1—FFT) after 19 weeks of culture and slightly increased fructan 1-exohydrolase activities (1-FEH). The root inulin concentration and the mean degree of polymerisation (DP) of the inulin chain remained however unaffected by water stress. It is concluded that root chicory displayed resistance to water stress, but that such a resistance is obtained at the expense of growth which, in turn, leads to significant decrease in inulin production. [less ▲]

Detailed reference viewed: 40 (1 ULg)
Full Text
See detailCombining in vivo and in silico experiments to unravel root water uptake dynamics
Lobet, Guillaume ULg; Bhowmick, Suman; Couvreur, Valentin et al

Poster (2012)

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailParameterizing a Dynamic Architectural Model of the Root System of Spring Barley from Minirhizotron Data
Garré, Sarah ULg; Pagès, Loïc; Laloy, Eric et al

in Vadose Zone Journal (2012)

The development of models describing water and nutrient fluxes to and through 3-D spatially resolved root structures in soils brings along the need to predict or describe the root architecture and root ... [more ▼]

The development of models describing water and nutrient fluxes to and through 3-D spatially resolved root structures in soils brings along the need to predict or describe the root architecture and root growth in detail. However, detailed data to calibrate and validate such architecture and growth models is typically not available. Here, we investigate the sensitivity of the root architecture model RootTyp (Pagès et al., 2004) to changes in its model parameters and reconstructed the root system architecture of barley growing in an undisturbed lysimeter using minirhizotron images at four different depths. Root arrival curves from a series of minirhizotron images were used to parameterize RootTyp using a range of realistic architectures. We adjusted a simple architecture to the data, which contained only long primary roots starting from the seed. This simple model unfortunately could not reproduce the observed increase of root density with depth. The model was subsequently improved by allowing root branching and elongation to be horizon-dependent and by making reiteration of root tips possible. Reiteration is an alternative form of branching, where secondary roots can become as long and thick as primary roots. Our results show that minirhizotron data do not contain enough information to warrant identification of the parameters governing these processes, as the additional parameters act similarly on data characteristics as the initial ones. Therefore, different experimental techniques should be combined to constrain the model parameters better in the future. [less ▲]

Detailed reference viewed: 45 (5 ULg)
Full Text
Peer Reviewed
See detailParameterizing the root system development of summer barley using minirhizotron data
Garré, Sarah ULg; Pagès, Loïc; Javaux, Mathieu et al

Poster (2011, April)

Detailed reference viewed: 11 (1 ULg)
Full Text
Peer Reviewed
See detailThree-Dimensional Electrical Resistivity Tomography to Monitor Root Zone Water Dynamics
Garré, Sarah ULg; Javaux, Mathieu; Vanderborght, Jan et al

in Vadose Zone Journal (2011), 10(1), 412-424

Knowledge of soil moisture dynamics and its spatial variability is essential to improve our understanding of root water uptake and soil moisture redistribution at the local scale and the field scale. We ... [more ▼]

Knowledge of soil moisture dynamics and its spatial variability is essential to improve our understanding of root water uptake and soil moisture redistribution at the local scale and the field scale. We investigated the potential and limitations of electrical resistivity tomography (ERT) to measure three-dimensional soil moisture changes and variability in a large, undisturbed, cropped soil column and examined the interactions between soil and root system. Our analysis sustained the value of ERT as a tool to monitor and quantify water contents and water content changes in the soil, as long as the root biomass does not influence the observed resistivity. This is shown using a global water mass balance and a local validation using time domain reflectometry (TDR) probes. The observed soil moisture variability was rather high compared to values reported in the literature for bare soil. The measured water depletion rate, being the result of combined effects of root water uptake and soil water redistribution, was compared with the evaporative demand and root length densities. We observed a gradual downward movement of the maximum water depletion rate combined with periods of redistribution when there was less transpiration. Finally, the maximum root length density was observed at −70 cm depth, pointing out that root architecture can strongly depend on soil characteristics and states. [less ▲]

Detailed reference viewed: 49 (5 ULg)
Peer Reviewed
See detailThe dynamic interplay between roots and soil moisture
Garré, Sarah ULg; Vanderborght, Jan; Javaux, Mathieu et al

in Geophysical Research Abstracts (2010, May)

Detailed reference viewed: 15 (4 ULg)
Full Text
Peer Reviewed
See detailComparison of Heterogeneous Transport Processes Observed with Electrical Resistivity Tomography in Two Soils
Garré, Sarah ULg; Koestel, Johannes; Günther, Thomas et al

in Vadose zone journal (2010), 9(2), 336-349

Preferential flow in soils can manifest itself in several ways. To illustrate this, we analyzed solute transport during a step tracer experiment in two soils expected to differ in their governing ... [more ▼]

Preferential flow in soils can manifest itself in several ways. To illustrate this, we analyzed solute transport during a step tracer experiment in two soils expected to differ in their governing transport processes: a loamy sand and a silty soil. By combining electrical resistivity tomography (ERT), time domain reflectometry, and effluent measurements, we observed different preferential flow phenomena. The transport process was characterized using voxel- and column-scale effective convective–dispersive equation (CDE) parameters, local velocities, and leaching surfaces. At the column scale, transport in the loamy sand was dominated by a homogenous convective–dispersive transport behavior, but at the scale of the voxel, preferential transport was observed. Transport in the silty soil was considerably more heterogeneous. Preferential flow was identified using ERT, voxel- and column-scale effective CDE parameters, local velocities, and leaching surfaces. In these soils, a clear influence of soil layering on solute transport was observed. [less ▲]

Detailed reference viewed: 22 (1 ULg)
Peer Reviewed
See detailComparison of transport in lysimeters with undisturbed loamy sand and silty soil using non-invasive imaging with electrical resistivity tomography
Garré, Sarah ULg; Koestel, Johannes; Javaux, Mathieu et al

Conference (2009, September)

Detailed reference viewed: 13 (1 ULg)
Peer Reviewed
See detailComparison of transport in lysimeters with undisturbed loamy sand and silty soil using non invasive imaging with electrical resistivity tomography.
Garré, Sarah ULg; Koestel, Johannes; Vanderborght, Jan et al

in Geophysical Research Abstracts (2009, April 23)

Detailed reference viewed: 10 (4 ULg)
Peer Reviewed
See detailEffects of crops on solute transport in undisturbed soil
Garré, Sarah ULg; Javaux, Mathieu; Vanderborght, Jan

Poster (2009)

Models predicting movement of surface applied chemicals incorporate knowledge on the water velocity field and moisture content distribution. Although the influence of root water uptake on solute transport ... [more ▼]

Models predicting movement of surface applied chemicals incorporate knowledge on the water velocity field and moisture content distribution. Although the influence of root water uptake on solute transport is commonly recognized as important, it has been studied sparsely. Yet, plants may take up a large part of the infiltrating water, thereby influencing the water flow pattern in the soil and concurrently solute transport processes. For this reason, experiments are required to investigate the relationship between plant root water uptake and flow field variability. The role of root water uptake on solute transport will be elucidated in two undisturbed soil columns. During three consecutive experiments, the influence of growing barley on tracer movement through a silty soil in two lysimeters will be followed. At the first stage, an inert tracer is put on the two bare lysimeters and leached with constant irrigation. As steady-state flow can be assumed, it is possible to follow the tracer movement in the column by ERT and to identify regions of preferential flow and solute transport parameters. During the second experiment, the tracer will be applied to mature barley grown in the lysimeters. Combining the information about the water content obtained with TDR with the relation between water content, soil solution salinity and bulk electrical conductivity, the soil solution salinity distribution can be derived from images of bulk electrical conductivity obtained with ERT. Root growth will be monitored using a minirhizotron. By comparing the transport parameters obtained after these two experiments, the effect of root water on the transport process can be quantified. When the columns are washed out and the barley is harvested, the third phase will be carried out under the same steady state flow conditions as in the first experiment to investigate the effect of dead roots on soil structure. [less ▲]

Detailed reference viewed: 15 (1 ULg)