Modelling rhizosphere transport in the presence of goethite, including competitive uptake of phosphate and arsenate

Autor: Krisztian Szegedi, Doris Vetterlein, Reinhold Jahn
Rok vydání: 2009
Předmět:
Zdroj: Plant and Soil. 330:481-501
ISSN: 1573-5036
0032-079X
DOI: 10.1007/s11104-009-0221-9
Popis: A modelling approach was used to extend the knowledge about the processes that affect the availability of the nutrient P and the toxic agent AsV in the rhizosphere in the presence of a strong sorbent. Based on compartment system experiments in which Zea mays was grown the following hypothesis were assumed: a) measured P concentration gradients can be explained by the mobilisation of P by the root exudate citrate, and b) measured AsV concentration gradients can be explained by the simultaneous effect of the competitive sorption of AsV and P and the competitive uptake of AsV and P. First, the feasibility of the applied description of soil chemical processes was justified. Then competitive uptake was implemented in the computer code using two different mathematical approaches. Our model calculation provided support for hypothesis a) and suggested that hypothesis b) has to be extended. The results show that the competitive uptake of AsV and P has an influence on AsV concentrations in the rhizosphere, but including competitive uptake was not sufficient to predict observed AsV concentration profiles. Recent results on plant As-metabolism like AsIII efflux and Si AsIII interaction probably have to be included in addition for simulation of measured AsV concentration profiles.
Databáze: OpenAIRE
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