环境科学学报(英文版)
環境科學學報(英文版)
배경과학학보(영문판)
JOURNAL OF ENVIRONMENTAL SCIENCES
2011年
3期
488-496
,共9页
trace elements%subsoil%topsoil%relationships
Field investigations were conducted to measure subsoil trace element content and factors influencing content in an intensive periurban market garden in Chenggong County, Yunnan Province, South-West China. The area was divided into three different geomorphological units: specifically, mountain (M), transition (T) and lacustrine (L). Mean trace element content in subsoil were determined for Pb (58.2mg/kg), Cd (0.89 mg/kg), Cu (129.2 mg/kg), and Zn (97.0 mg/kg). Strong significant relationships between trace element content in topsoil and subsoil were observed. Both Pb and Zn were accumulated in topsoil (RTS (ratio of mean trace element in topsoil to subsoil)of Pb and Zn ≥1.0) and Cd and Cu in subsoil (RTS of Cd and Cu ≤1.0). Subsoil trace element content was related to relief, stoniness,soil color, clay content, and cation exchange capacity. Except for 7.5 YR (yellow-red) color, trace element content increased with color intensity from brown to reddish brown. Significant positive relationships were observed between Fe content and that of Pb and Cu.Trace element content in mountain unit subsoil was higher than in transition and lacustrine units (M > T > L), except for Cu (T > M >L). Mean trace element content in calcareous subsoil was higher than in sandstone and shale. Mean trace element content in clay texture subsoil was higher than in sandy and sandy loam subsoil, and higher Cu and Zn content in subsoil with few mottles. It is possible to model Pb, Cd, Cu, and Zn distribution in subsoil physico-chemical characteristics to help improve agricultural practice.