A
sloping field of
black soil in northeast China was selected to conduct soil redistribution for the past nearly 50 and 100 years, and to calculate the carbon budget by using ~(137)Cs and fly ash tracer techniques. The results showed that the depth of original buried layer in foot-
slope and toe-slope located at 70 and 80cm
respectively, and the content of SOC was 5.23 and 0.43g/kg more than those of overlying soil. Summit, shoulder-slope and back-slope suffered erosion with the rate of 0.2,5and 2.2 mm/yr, respectively based on distribution of ( ~(137)Cs) and fly ash with soil depth. The depths of fly ash attainment in foot-slope and toe-slope were 70 and 80 cm respectively, and were well consistence with their buried surface horizon, which indicated the depositional areas had been annually plowed before locomotives used. Most of the eroded soil materials in depositional areas were from shoulder-slope and back-slope,
accumulated in foot-slope firstly, then transferred to toe-slope gradually according to soil surface of various years. The loss of SOC in summit, shoulder-slope and back-slope was 683 kg in all in the past nearly 100 years, among which 418 kg (about 60%) was accumulated in foot-slope and toe-slope depressions, 257 kg of soil carbon was accumulated in most recent 50 years.