- Salinity is one of the major abiotic stresses limiting plant growth and productivity, particularly in arid and semi-arid areas. The dynamic cross talks between soil salinity, water content, root water uptake and transpiration can be simulated by various models, which can be useful tools for soil management and irrigation. These simulation models rely on plant-specific relationships between root zone salinity, water content, and root water uptake that need to be provided as inputs to the model, but depend strongly on environmental conditions. The main aim of this study is to obtain insight into the factors that control these plant-specific relationships. We hypothesize that the key to obtaining this insight is to resolve the flow and transport processes within the rhizosphere of individual roots, and to couple them with the flow and transport processes within the plant’s root system.