| Soil contamination with heavy metal has become an important issue that affects public health. So there is an urgent requirement for selecting appropriate technologies to solve food safety problems due to soil contamination. In this study, a field experiment was performed to study the accumulation and remediation efficiency of heavy metals in the rotation system of Brassica juncea and Elsholtzia splendens on a heavy metal-contaminated field. The results showed that the straw biomass of the oilseed rape reached 7.67 t·hm-2 and the seed yield was 1.59 t·hm-2. The concentrations of Cd and Cu in the seed were 90% and 33% higher than the permissible limits, respectively. In the rotation system of Brassica juncea and Elsholtzia splendens, the total uptake of Cd and Cu by shoots were 35.16 g·hm-2 and 400.68 g·hm-2, respectively, in which Brassica juncea accounted for 83% of the total Cd uptake and Elsholtzia splendens accounted for 73%. The remediation efficiency was 0.2% for Cd and only 0.07% for Cu. These results indicated that the rotation of Brassica juncea and Elsholtzia splendens was not suitable for the highly copper and cadmium-contaminated soil. Not only the quality of the harvested seed does not meet the requirements of food hygiene standards, but also it will take a long time to remediate the polluted soil through the phytoremediation. |
