Assessing Soil Erosion Rates on Manually-Tilled Hillslopes in the Sichuan Hilly Basin Using ^137Cs and ^210pbex Measurements

• Published in: Pedosphere Vol. 17; no. 3; pp. 273 - 283
• Main Authors: ZHENG, Jin-Jun, HE, Xiu-Bin, WALLING, D., ZHANG, Xin-Bao, FLANAGAN, D., QI, Yong-Qing
• Format: Journal Article
• Language: English
• Published: Graduate University of the Chinese Academy of Sciences, Beijing 100049 China%Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041 China%Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041 China 01-06-2007; Department of Geography, University of Exeter, Exeter, EX4 4RJ UK%Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041 China; Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041 China; State Key laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences,Xi'an 710075 China%USDA-ARS National Soil Erosion Research Laboratory, West Lafayette, Indiana 47907 USA%Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 China
• Subjects: 210pbex; 丘陵盆地; 人工耕种山坡; 土壤侵蚀速度; 铯137; 210Pbex; hoe tillage; purple soil; soil erosion; 137Cs
• ISSN: 1002-0160; 2210-5107
• DOI: 10.1016/s1002-0160(07)60034-4

Purple soils are widely distributed in the Sichuan Hilly Basin and are highly susceptible to erosion, especially on the cultivated slopes. Quantitative assessment of the erosion rates is, however, difficult due to small size of the plots of the manually-tilled land, the complex land use, and steep hillslopes. ^137Cs and ^210Pbex （excess ^210Pb） tracing techniques were used to investigate the spatial pattern of soil erosion rates associated with slope-land under hoe tillage in Neijiang of the Sichuan Hilly Basin. The ^137Cs and ^210Pbex inventories at the top of the cultivated slope were extremely low, and the highest inventories were found at the bottom of the cultivated slope. By combining the erosion rates estimates provided by both ^137Cs and 21~Pbex measurements, the weighted mean net soil loss from the study slope was estimated to be 3 100 t km^-2 year^-1, which was significantly less than 6 930 t km^-2 year^-1 reported for runoff plots on a 10° cultivated slope at the Suining Station of Soil Erosion. The spatial pattern of soil erosion rates on the steep agricultural land showed that hoe tillage played an important role in soil redistribution along the slope. Also, traditional farming practices had a significant role in reducing soil loss, leading to a lower net erosion rate for the field.