Pedosphere 23(3): 385--394, 2013
ISSN 1002-0160/CN 32-1315/P
©2013 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Phosphorus loss from dry sloping lands of Three Gorges Reservoir area, China |
HU Zheng-Feng1, GAO Ming1 , XIE De-Ti1,2 and WANG Zi-Fang1 |
1 College of Resources & Environment, Southwest University, Chongqing 400716 (China)
2Chongqing Municipal Environmental Protection Bureau, Chongqing 401147 (China) |
| ABSTRACT |
| Eutrophication in the Three Gorges Reservoir has become a serious issue, and phosphorus (P) is the nutrient thought to be primarily responsible although there are few studies about P loss from the mostly sloping farmlands of the area. This work investigated the amounts and forms of P loss from 9 farmlands with the slopes of 4°, 9°, and 17° in a small watershed, Wangjiagou in Fuling District, Chongqing of China. The slope of the relationship between runoff and rainfall increased with field slope; i.e., there was a significant interaction between the effects of rainfall and field slope on water export. For sediment export by surface runoff, there was no interaction between field slope and rainfall, and the intercept of the relationship between rainfall and sediment loss was significantly different for the 3 slopes. The main P loss was from sediments, regardless of slope. In the runoff water, particulate P was the largest P fraction, and its loss was greatest from the steepest land and least from the flattest. The release of total P and available P from sediments followed the same trend. The P loss during May to July in Wangjiagou was more than 60% of the annual total. |
| Key Words: agricultural production area, erosion, nutrient loss, purple soil, soil loss |
| Citation: Hu, Z. F., Gao, M., Xie, D. T. and Wang, Z. F. 2013. Phosphorus loss from dry sloping lands of Three Gorges Reservoir area, China. Pedosphere. 23(3): 385-394. |
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