Pedosphere 10(4): 317--321, 2000
ISSN 1002-0160/CN 32-1315/P
©2000 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Soil components affecting phosphate sorption parameters of acid paddy soils in Guangdong Province |
| LI Hua-Xing, ZHANG Xin-Ming and LIU Yuan-Jin |
| College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642 (China) |
| ABSTRACT |
| Soil components affecting phosphate sorption parameters were studied using acid paddy soils derived from basalt, granite, sand-shale and the Pearl River Delta sediments, respectively, in Guangdong Province. For each soil, seven 2.50 g subsamples were equilibrated with 50 mL 0.02 mol L-1 (pH=7.0) of KCl containing 0, 5, 10, 15, 25, 50 and 100 mg P kg-1, respectively, in order to derive P sorption parameters (P sorption maximum, P sorption intensity factor and maximum buffer capacity) by Langmuir isotherm equation. It was shown that the main soil components influencing phosphate sorption maximum (Xm) included soil clay, pH, amorphous iron oxide (Feo) and amorphous aluminum oxide (Alo), with their effects in the order of Alo > Feo > pH > clay. Among these components, pH had a negative effect, and the others had a positive effect. Organic matter (OM) was the only soil component influencing P sorption intensity factor (K). The main components influencing maximum phosphate buffer capacity (MBC) consisted of soil clay, OM, pH, Feo and Alo, with their effects in the order of Alo > OM > pH > Feo > clay. Path analysis indicated that among the components with positive effects on maximum phosphate buffer capacity (MBC), the effect was in the order of Alo > Feo > Clay, while among the components with negative effects, OM > pH. OM played an important role in mobilizing phosphate in acid paddy soils mainly through decreasing the sorption intensity of phosphate by soil particles. |
| Key Words: Guangdong Province, phosphate sorption parameters, soil components |
| Citation: Li, H. X., Zhang, X. M. and Liu, Y. J. 2000. Soil components affecting phosphate sorption parameters of acid paddy soils in Guangdong Province. Pedosphere. 10(4): 317-321. |
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