Effect of long-term fertilization on the bioavailability of cadmium in soil

摘要

Use of inorganic fertilizers over a long period of time has raised concern regarding the toxic accumulation of trace components in the environment. It is considered to be the principal sources of minor and trace elements in arable soils. Cadmium is found to be one of the toxic metals which accumulates in soil relatively in large quantities through phosphatic fertilizers and further it contaminate soil health and ground water quality, which leads to possible health and ecological effects. Hence the present study was taken to assess the bioavailability of cadmium. The study was carried out in long-term fertilizer experiment which has been in progress since 1972 at Tamil Nadu Agricultural University, Coimbatore. The bioavailability was assessed by sequential extraction. Although the percentage of water soluble and exchangeable fraction was low, the concentration of cadmium was high and may favor mobility of this metal to subsurface soil. The sum of individual fraction versus the whole soil digestion values compared favorably and this demonstrated that the fractionation scheme used in this study was found to be satisfactory.