Pedosphere 10(1): 21--30, 2000
ISSN 1002-0160/CN 32-1315/P
©2000 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Effect of heavy metal pollution on potassium behavior in Typic Udic Ferrisol |
TU Cong , ZHENG Chun-Rong and CHEN Huai-Man |
| Laboratory of Material Cycling in Pedosphere, Institute of Soil Science, the Chinese Academy of Sciences, P. O. Box 821, Nanjing 210008 (China) |
| ABSTRACT |
| The indirect influence of heavy metal contamination of soil on nutrient availability may need to be taken into consideration when determining overall effects of heavy metals. A laboratory experiment was performed to study the effects of combined pollution of Cu, Pb, Zn and Cd on soil K status as indicated by chemical fractions, adsorption-desorption and quantity/intensity (Q/I) relationship of K in a Typic Udic Ferrisol (red soil), by employing uniform design and single factor design. Compared to the control, content of exchangeable K was decreased, but that of soluble K increased in the samples contaminated with heavy metals. Due to heavy metal pollution, potassium adsorption was reduced by 5 to 22%, whereas the desorption percentage of adsorbed K increased by 2 to 32%. The Q/I curves shifted downward, potassium buffering capacity (PBCK) decreased, and equilibrium activity ratio values (ARKo) increased with increasing heavy metal pollution. These influences followed the sequences of Pb>Cu>Zn and combined pollution>individual metals. Displacement of K from cation exchange sites and decrease in soil cation exchange capacity due to heavy metals led to changes of soil K behaviour. The findings suggest that heavy metal pollution of soil might aggravate the degradation of soil K fertility by decreasing K adsorption and buffering capacity and increasing desorption. |
| Key Words: heavy metals, potassium behaviors, Typic Udic Ferrisol |
| Citation: Tu, C., Zheng, C. R. and Chen, H. M. 2000. Effect of heavy metal pollution on potassium behavior in Typic Udic Ferrisol. Pedosphere. 10(1): 21-30. |
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