Concentrations et croissance de lombriciens et de plantes dans des sols contaminés ou non par Cd, Cu, Fe, Pb et Zn: Interactions plante-sol-lombricien

Abstract

Three microcosms have been prepared from soils which differ in their contents of five trace elements (Cd, Cu, Fe, Pb and Zn). All prepared soils were planted with rye grass, Lolium perenne L., and an earthworm Lumbricus terrestris L. was introduced in only half of them. The aim of this second part of the work is to study, on the one hand, the growth and concentration of trace elements in the shoots and roots of rye grass, and on the other hand, the interactions between the chemical extraction of soil trace elements and the biological concentration of these elements in earthworms and in the two vegetable parts of rye grass. The vegetable biomass of these two parts were increased with soil contamination and the presence of earthworms, with the exception of the root biomass in 100% contaminated soils. The concentration of trace elements is more important in the roots than in the foliar parts. Generally, the presence of L. terrestris increased the concentration of trace elements in the two vegetable parts with the exception of that of Fe and Pb in the roots. The trace element contents of rye grass, in particularly their roots, have been better correlated with that of soils than the earthworm tissue contents. The presence of earthworms increased the number of positive correlations between the trace element concentrations in the two vegetable parts of rye grass.