Pedosphere 6(2): 111--119, 1996
ISSN 1002-0160/CN 32-1315/P
©1996 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Characterization of gleyization of paddy soils in the middle reaches of the Yangtze River |
| PAN Shu-Zheng |
| Institute of Soil Science, Acodemia Silica, Nanjing 210008(China) |
| ABSTRACT |
| The gleyization of representative paddy soils in the middle reaches of the Yangtze River was characterized, taking oxidation-reduction potential(Eh), the amount of active reducing substances and the forms of iron and manganese as the parameters. The Eh value was linearly related with the logarithm of the amount of active reducing substances, which was contributed by ferrous iron by 83% on an average. The degree of gleyization of different horizons was graded as ungleyed, slightly gleyed, mildly gleyed and gleyed. The Eh of the four grades was > 500, 300-500, 100-300 and < 100 mV, respectively, and the corresponding amount of active reducing substances was < 1, 1-7, 7-30 and > 30 mmolc kg-1, respectively. The amount of ferrous iron of the four grades was < 0.5, 0.5-5, 5-25 and > 25 mmol kg-1, respectively. The extent of gleyization of a soil was classified as upper-gleyed, middle-gleyed and lower-gleyed, depending on whether the depth of the gley horizon was less than 30 cm, 30-60 cm or more than 60 cm. |
| Key Words: ferrous iron, gleyization, paddy soil, reducing substances, oxidation-reduction potential |
| Citation: Pan, S. Z. 1996. Characterization of gleyization of paddy soils in the middle reaches of the Yangtze River. Pedosphere. 6(2): 111-119. |
|
View Full Text
|
|
|
|
