Modeling and Simulation of Soil-Root Interactions
A great amount of water that infiltrates in the subsurface is returned back to the atmosphere via root water uptake and plant transpiration. Therefore, plants play an important role in the global water cycle and groundwater management.
Water transfer through plants is a passive process, driven by the water potential gradient between the soil and the atmosphere. Beyond the ground surface, the water uptake by plant roots is thus highly impacted by the spatial distribution of the water potential in the soil and in the root, and by the root system architecture (RSA). The spatial distribution and the magnitude of the uptake will also depend on the spatial distribution of the root radial and of the soil conductivities. In addition, the distribution of salts and nutrients around the plant roots are affected by the velocity field and solute accumulation in the root-zone, as well as solute uptake by the plant roots, are depending again on local root-soil interaction along the RSA.
Most of currently available experimental devices do not allow an accurate measurement of soil and root variables locally, which make predictions water and solute processes in coupled soil-root systems very difficult to realize. Numerical models are able to account for the three-dimensional distributions of RSA and soil properties and are therefore helpful to understand interactions in the groundwater-soil-plant-atmosphere system. In this project, a high resolution root-soil model is developed on plant-scale, using the framework Dumux. The model combines biological, chemical and physical processes in soil, roots, and at root-soil interfaces and is used to investigate effects of soil heterogeneity on water uptake, combination of water uptake and solute transport, and salt precipitation in the root zone.