Low phosphorus (P) availability in calcareous is due to low solubility of P-controlling mineral phases at alkaline pHs, mainly Ca-P mineral phases. Rhizosphere processes can increase P availability and uptake. In the case of faba bean, root-induced acidification and Ca/P uptake induce the dissolution of Ca-P minerals (Houassine et al., 2019). Advanced soil-plant models have the ability to solve in a coupled way the complex set of geochemical, physical and biological processes controlling nutrient acquisition by plants from soil (Gérard et al., 2017). Their application to the field should be useful to integrate multidisciplinary knowledge, to improve our understanding, and to enhance the link between experimentalists and modelers for a better knowledge of the systems to model in future applications. This presentation aims at showing the results of an application of the soil-plant model Min3P-ArchiSimple to P uptake by faba bean in calcareous soil having different bulk and rhizosphere properties. We modelled both P rich and P poor N fixing soils. Results are in good agreement by considering a decrease of the effective dissolution rate constant of Ca-P minerals with P richness, in spite of the greater acidification and root exploration. This is consistent we the expected decrease of their reactive surface area with their abundance. Interestingly different concentration patterns where obtained in the root zone between P rich and P poor soils. After calibration on real data, our model predicts the extent of acidification and root exploration to be reached in P poor soils in order to increase P uptake to the level observed in P rich soils.