Pedosphere 8(3): 237--244, 1998
ISSN 1002-0160/CN 32-1315/P
©1998 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Interaction of Pb and Cd in soil-water-plant system and its mechanism: Ⅱ. Pb-Cd interaction in rhizosphere |
| CHEN Huai-Man, LIN Qi and ZHENG Chun-Rong |
| Institute of Soil Science, the Chinese Academy of Sciences, P. O. Box 821, Nanjing 210008 (China) |
| ABSTRACT |
| The interaction of Pb-Cd can be observed not only in the uptake process of elements by plants and in their influence on the growth, but also in rhizosphere. The changes in extractable Cd and Pb concentrations in the rhizosphere soil of rice plants, root exudates from wheat and wheat plant and their complexing capacity with Pb and Cd were investigated under different Pb and Cd treatments. Results showed that the concentration of extractable Cd in the rhizosphere of rice in red soil was markedly increased by Pb-Cd interaction. It increased by 56% in the treatment with Pb and Cd added against that in the treatment with only Cd added in soil. The considerable differences in both composition and amount of root exudate from wheat and rice were found among different treatments. Pb and Cd might be complexed by root exudates. The concentrations of free Pb and Cd in the solution were increased markedly by adding root exudate from wheat and decreased by that from rice due to Pb-Cd interaction. The distribution patterns of Pb and Cd in roots were affected by Pb-Cd interaction, which accelerated transport of Pb into internal tissue and retarded accumulation of Cd in external tissue. |
| Key Words: Cd, interaction, Pb, red soil, rhizosphere of rice and wheat |
| Citation: Chen, H. M., Lin, Q. and Zheng, C. R. 1998. Interaction of Pb and Cd in soil-water-plant system and its mechanism: Ⅱ. Pb-Cd interaction in rhizosphere. Pedosphere. 8(3): 237-244. |
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