Pedosphere 8(1): 53--58, 1998
ISSN 1002-0160/CN 32-1315/P
©1998 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Iron oxides and their relations to colors in some soils of southern China |
| ZHANG Ming-Kui1, M. J. WILSON2 and HE Zhen-Li1 |
1 Department of Soil Science and Water Resource, Zhejiang Agricultural University, Hangzhou 310029 (china)
2 Soils and Soil Microbiology Division, Macaulay Land Use Research Institute, Aberdeen, AB9 2QJ (UK) |
| ABSTRACT |
| Iron oxides from 33 samples of 25 soils derived from various parent materials in the southern China were studied using NaOH selective dissolution technique and X-ray diffraction (XRD). Goethite and hematite were the only two crystalline Fe oxides occurring in a significant quantity. The goethite/(goethite+hematite) ratios ranged from 0 to 1, being the highest in yellow soil, some yellow-red soils and saprolite samples and the lowest in soils derived from purple sandstone where only hematite was present. Al substitution in goethite ranged from 6.6 to 29.9 mol % with a mean value of 16.7 mol %, while substitution of Al in hematite ranged from 0 to 12.1 mol %.The values of Al substitution of hematite in coexisting goethite and hematite were closely related with corresponding values of goethite (r=0.7292, P<0.01, n=27). The redness rating of soils increased linearly with increasing amount of hematite (r=0.8109, P<0.01). It was suggested that redness rating could be used to crudely estimate hematite contents of soils. |
| Key Words: Al substitution, color, iron oxides, southern China |
| Citation: Zhang, M. K., Wilson, M. J. and He, Z. L. 1998. Iron oxides and their relations to colors in some soils of southern China. Pedosphere. 8(1): 53-58. |
| |
|
View Full Text
|
|
|
|
