Fig. 2

Variation of Cd and Pb content in soil and maize in different experimental groups Note: Asterisks indicate significant differences: *(P < 0.05), **(P < 0.01), ***(P < 0.001). Data are presented as mean ± standard deviation, (n = 3). In (a), green bars represent Cd contents of soil, green squares with lines represent Cd contents of Zea mays L.; in (b), blue bars represent Pb contents of soil, light blue squares with lines represent Pb contents of Zea mays L. Red dashed lines in both charts represent background values.