Toxic Effect of Cadmium on Soil Microbial Activity and Plant Growth: Influence of Soil Characteristics and Management

摘要

In this study, we use biochemical measures related with the soil microbial activity to evaluate the toxic effects of Cd in two semiarid soils of different characteristics, which have been submitted to different management practices. The Cd concentrations which produced a 5, 10 and 50% inhibition of the parameter studied (Ecological Dose values) were calculated after incubation periods of 3 hours, 20 days and 60 days. In addition, Lolium perenne was cultivated in both soils containing the different Cd concentrations in order to ascertain the effect of Cd contamination on plant growth. When the dehydrogenase activity and ATP content of the soils were analysed, the calculated ED values were higher in the agricultural soil than in the abandoned soil. The yield of Lolium perenne fell gradually with increasing concentrations of Cd in the soil, the lowest decrease being observed in the agricultural soil at 60 days. The concentration of Cd in the plants increased gradually with the total and DTPA-extractable concentration of this heavy metal in the soil.