Effect of cadmium sulfate and Cd-enriched sewage sludge on the growth and Cd uptake of rice plant

Cadmium contamination in soil is now an important agricultural and environmental issue throughout the world. To investigate the effect of Cd toxicity on dry matter yield and Cd uptake of rice plant, a pot experiment was conducted with two Cd sources (CdSO4 or Cd-enriched sewage sludge) and five Cd levels (0, 10, 30, 60, and 90 mg Cd kg-1 soil as CdSO4, and 0.18 (control), 10, 30, 60, and 90 mg Cd kg-1 soil as Cd-enriched sewage sludge). Results showed that with increasing Cd levels as CdSO4 or Cd-enriched sewage sludge, no significant differences in root and straw dry weights of rice were observed; however, grain dry weight decreased significantly. Therefore addition of inorganic form of Cd to soil decreased rice yield more than similar Cd levels in the form of Cd-enriched sewage sludge. Application of Cd in soil had significant influence on Cd uptake in root, straw, and grain of rice plant. Root, straw, and grain Cd uptake significantly increased with increasing Cd levels (as CdSO4 or Cd-enriched sewage sludge), as compared to that of control. More Cd was accumulated in roots than straw and grain of rice plant. Root and straw dry weight and Cd uptake of rice plant were higher in Cd-enriched sewage sludge than CdSO4 source.

کلیدواژه ها:

Cadmium sulphate ، Cd-enriched sewage sludge ، rice growth ، Cd uptake