Effects of Sewage Sludge, Animal Manure, Compost and Cadmium Chloride on Cadmium Accumulation in Corn and Alfalfa

摘要

The objective of this study was to investigate cadmium (Cd) availability to alfalfa and corn in a soil amended with organic and inorganic Cd sources. A greenhouse experiment with completely randomized design performed with four treatments and three replicates. Soil was treated with 25 t ha–1 sewage sludge, compost and cow manure including three rates of Cd (initial level, 5 and 10 mg kg–1). An inorganic Cd source was also applied at two rates of 5 and 10 mg Cd kg–1 in the form of CdCl2 salt. Results displayed that plants grown in soil treated with CdCl2 salt accumulated significantly greater Cd in their tissues compared to those grown in soil treated with organic amendments. Amount of Cd translocated to the shoots of plants in the CdCl2 treatment was greater compared with those in organic residuals treatments. Results from this experiment point to the fact that the Cd source, loading rate and plant species are important factors in evaluation of Cd phytoavailability.