Study of the trace metal ion influence on the turnover of soil organic matter in cultivated contaminated soils

• Published in: Environmental pollution (1987) 2006-08, Vol.142 (3), p.521-529
• Main Authors: Dumat, C., Quenea, K., Bermond, A., Toinen, S., Benedetti, M.F.
• Format: Article
• Language: English
• Subjects: Agriculture; Agronomy. Soil science and plant productions; Applied sciences; Biodegradation, Environmental; Biological and medical sciences; Biological and physicochemical properties of pollutants. Interaction in the soil; Biomass; Cadmium - analysis; Carbon Isotopes - analysis; Copper - analysis; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Pollution - analysis; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Geologic Sediments; Humic Substances; Lead - analysis; Metallurgy; Metals - toxicity; Nitrogen - analysis; Pollution; Pollution, environment geology; Size fractionation; Soil - analysis; Soil and sediments pollution; Soil and water pollution; Soil organic matter dynamic; Soil Pollutants - toxicity; Soil science; Spectrophotometry, Atomic; Stable isotopic carbon ratio; Trace metal; Zea mays; Zinc - analysis
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2005.10.027

The role of metals in the behaviour of soil organic matter (SOM) is not well documented. Therefore, we investigated the influence of metals (Pb, Zn, Cu and Cd) on the dynamic of SOM in contaminated soils where maize (C 4 plant) replaced C 3 cultures. Three pseudogley brown leached soil profiles under maize with a decreasing gradient in metals concentrations were sampled. On size fractions, stable carbon isotopic ratio ( δ 13C), metals, organic carbon and nitrogen concentrations were measured in function of depth. The determined sequence for the amount of C 4 organic matter in the bulk fractions: M 3 (0.9) > M 2 (0.4) > M 1 (0.3) is in agreement with a significant influence of metals on the SOM turnover. New C 4 SOM, mainly present in the labile coarser fractions and less contaminated by metals than the stabilised C 3 SOM of the clay fraction, is more easily degraded by microorganisms. Measure of δ 13C and total metal concentrations in size fractions of contaminated soils suggests an influence of metals on the soil organic matter dynamic.