Seminar Florian CAJOT

Modeling water transfer in soil in the presence of amphiphilic matter: application to the rhizosphere


After a brief introduction about the rhizosphere and the amphiphilic matter, we consider the interaction between the soil and the amphiphilic matter and the wettability of the soil. After reviewing the free energy in the soil and modeling approaches, we establish the water transfer in an effective porous media where capillarity and wettability are incorporated. This model is employed to study and discuss (i) the interaction matrix/water, (ii) the water transfer in a homogeneous medium, and (iii) the water transfer in a stratified porous medium. As a result we distinguish four water transfer dynamics.

Second, we employ this theory with experimental results realized in our lab to calibrate some parameters of the model. After introducing coupled model, we discuss the parametrization of the model. This calibrated model is applyed to different situation: (i) drop infiltration in a porous medium with different amphiphilic concentration and initial saturation and (ii) water transfer in presence of a single root. Results are given for one-dimensional horizontal substrates.