Verification and intercomparison of reactive transport codes to describe root-uptake

B. Nowack, K.U. Mayer, S.E. Oswald, W. van Beinum, C.A.J. Appelo, Diederik Jacques, P. Seuntjens, F. Gérard, B. Jaillard, A. Schnepf, T. Roose

    Research outputpeer-review


    The aim of this work was to evaluate three existing coupled speciation-transport tools to model rhizosphere processes. We implemented and tested a simple rhizosphere model with three geochemical computational tools (ORCHESTRA, MIN3P, and PHREEQC). The first step was an accuracy analysis of the different solution strategies by comparing the numerical results to the analytical solution of solute uptake (K or Ca) by a single cylindrical root. All models are able to reproduce the concentration profiles as well as the uptake flux. The relative error of the simulated concentration profile decreases with increasing distance from the root. The uptake flux was simulated for all codes with less than 5% error for K and less than 0.4% for Ca. The strength of the codes presented in this paper is that they can also be used to investigate more complex and coupled biogeochemical processes in rhizosphere models. This is shown exemplarily with simulations involving both exudation and uptake and the simultaneous uptake of solute and water.
    Original languageEnglish
    Pages (from-to)305-321
    JournalPlant and Soil
    Issue number1-2
    StatePublished - Jul 2006

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