Migration law of heavy metal cadmium in soil-root interface systems

The distribution characteristics of heavy metals in soil-root systems have great significance for the research into soil pollution risk assessment and the phytoremediation effect. This paper takes ligustrum lucidum as an example, based on the characteristics of adsorption of heavy metals in soil by woody plants, lays out sampling points, and using software Sufer for the Kiging interpolation analysis, and the horizontal migration law of heavy metal cadmium in the soil-root interface system is simulated. Through multi-model statistical regression trend analysis, the horizontal migration mechanism of cadmium in dif- ferent sections is discussed. The results show that: ① under horizontal migration law: the migration ability of Cd is weaker near the Ligustrum lucidum root (0-30 cm); with the root extension, the migration ability of Cd gradually is strengthened, and the main range of the migration ability is 60-90 cm. In addition, its migration law follows the cubic curve mode. ② under lon- gitudinal migration law: based on the Kriging method, migration models Z(hi) of heavy metal Cd in any depth of hi are con- structed and fit the correlation coefficient R 2 >0.95.