Pedosphere 18(6): 785--794, 2008
ISSN 1002-0160/CN 32-1315/P
©2008 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Changes in phosphorus fractions, pH, and phosphatase activity in the rhizosphere of two rice genotypes |
LI Yong-Fu 1,2, LUO An-Cheng1, WEI Xing-Hua3 and YAO Xu-Guo1 |
1 College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China). E-mail: yfli2000@163.com;
2 School of Environmental Science and Technology, Zhejiang Forestry University, Lin'an 311300 (China);
3 State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 (China) |
| ABSTRACT |
| A rhizobox experiment with two phosphorus (P) treatments, zero-P (0 mg P kg-1) and plus-P (100 mg P kg-1) as Ca(H2PO4)2·H2O, was conducted to study the chemical and biochemical properties in the rhizosphere of two rice genotypes (cv. Zhongbu 51 and Pembe) different in P uptake ability and their relationship with the depletion of soil P fractions. Plant P uptake, pH, phosphatase activity, and soil P fractions in the rhizosphere were measured. Both total dry weight and total P uptake of Pembe were significantly (P < 0.05) higher than those of Zhongbu 51 in the zero-P and plus-P treatments. Significant depletions of resin-Pi, NaHCO3-Pi, NaHCO3-Po, and NaOH-Pi, where Pi stands for inorganic P and Po for organic P, were observed in the rhizosphere of both Zhongbu 51 and Pembe under both P treatments. Pembe showed a greater ability than Zhongbu 51 in depleting resin-Pi, NaHCO3-Pi, NaHCO3-Po, NaOH-Pi, and NaOH-Po in the rhizosphere. HCl-Pi and residual-P were not depleted in the rhizosphere of both genotypes, regardless of P treatments despite significant acidification in the rhizosphere of Pembe under zero-P treatment. Higher acid phosphatase (AcPME) activity and alkaline phosphatase (AlPME) activity were observed in the rhizosphere of both Zhongbu 51 and Pembe compared to the corresponding controls without plant. AcPME activity was negatively (P < 0.01) correlated to NaHCO3-Po concentration in the rhizosphere of both Zhongbu 51 and Pembe, suggesting that AcPME was associated with the mineralization of soil organic P. |
| Key Words: phosphatase, phosphorus fractions, rhizosphere, rice genotypes, soil pH |
| Citation: Li, Y. F., Luo, A. C., Wei, X. H. and Yao, X. G. 2008. Changes in phosphorus fractions, pH, and phosphatase activity in the rhizosphere of two rice genotypes. Pedosphere. 18(6): 785-794. |
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