[Effect of different cultivation practices on Fe and Cd content in iron plaque outside rice root and Cd content in...

The effects of different cultivation practices-traditional flooding (TF), film mulching (FM), straw mulching (SM), and wetting cultivation (WC)-on Cd concentrations in Indica and Japonica roots and on Cd and Fe concentrations in iron plaque outside the roots were studied at different growth stages (tillering, booting, filling and harvest) with a Cd-polluted soil. The results showed that in all practices, the mean Fe concentration in iron plaque and the mean Cd concentration in roots of Japonica at tillering stage were 6.37 mg.mg-1 and 25.49 mg.kg-1, and greater than those of Indica, which were 4.52 mg.mg-1 and 16.37 mg.kg-1 respectively; at booting stage, the mean Fe and Cd concentrations in iron plaque and the mean Cd concentrations of Japonica were 1.60, 16.35 and 54.68 mg.kg-1, and greater than those of Indica, which were 1.06 mg.mg-1, 9.56 and 43.31 mg.kg-1, respectively; at filling stage, the Fe concentrations in iron plaque of Japonica in SM and WC were 0.89 and 1.00 mg.mg-1, and those of Indica were 0.63 and 0.30 mg.mg-1; in all practices, the mean Cd concentrations in iron plaque and root of Japonica were 15.23 and 73.68 mg.kg-1, and those of Indica were 3.46 and 52.38 mg.kg-1; at harvest stage, the Fe concentration in iron was plaque of Indica in TF was 1.21 mg.mg-1 and that of Japonica was 0.65 mg.mg-1, but that of Japonica in SM was 0.94 mg.mg-1 and that of Indica in SM was 0.55 mg.mg-1; the Cd concentration in iron plaque of Japonica in WC was 7.96 mg.kg-1, and that of Indica was 5.09 mg.kg-1; the mean Cd concentration in root of Japonica was 54.53 mg.kg-1 and that of Indica was 35.91 mg.kg-1 in all practices.