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Metal uptake by Lolium perenne in contaminated soils using a four‐step approach
Author(s) -
Kalis Erwin J. J.,
Temminghoff Erwin J. M.,
Visser Anneloes,
van Riemsdijk Willem H.
Publication year - 2007
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/06-173r.1
Subject(s) - lolium perenne , metal , chemistry , shoot , soil water , adsorption , environmental chemistry , metal ions in aqueous solution , agronomy , soil science , poaceae , environmental science , biology , organic chemistry
—Most research dealing with soil (solution) speciation and metal uptake by plants has focused on the relationships between a certain bioavailable fraction in the soil and metal uptake by aboveground parts of the plants. Here, a new approach to interpretation of metal uptake is presented that considers four steps: First, the metal concentration in the soil solution is related to the total metal content of the soil. Second, the metal adsorption to the root surface is related to the metal concentration in the soil solution. Third, the metal content in the roots is related to the adsorption of metal ions to the root surface. Fourth, the metal content in the shoots is related to the metal content in the roots. For grass grown on 10 different soils, it is shown that the metal adsorption to the root surface is pH‐dependently related to the free or total metal concentration in the soil solution. The metal content in the roots depends linearly on the metal adsorption at the root surface, whereas the metal content in the shoots depends on the metal content in the roots, either linearly (Zn) or reaching a maximum (Cu, Pb, and Cd). For the Ni content in the shoots as a function of the root content, the relation is pH dependent, probably because of the competition effects of Ca. The pH of the soil has to be taken into account when CaCl 2 extractions are used as a basis for risk assessment toward plants.