a decreasing trendp < 0.05
Similarly, the Cd contents in shells showed a decreasing trend that was similar to those for roots and shoots in the maturity stage ( p < 0.05), and these contents decreased by 5.76, 23.02, 41.73, 42.45, and 43.17% for the C300, C600, C900, C1200 and C1500 treatments compared to C0, respectively (Fig. 2 c).