Abstract:

【Objective】 Heavy metals accumulation and their influential factors were studied in different land use soils, which will provide a theoretical basis for controlling the content of heavy metals in soils. 【Method】 To identify the effects of land use on the accumulation of heavy metals in soils, 148 samples were collected from four land use types including greenhouse, open vegetable field, maize field and forest land in Siping area, Jilin Province, and Cr, Ni, Cu, As, Cd, Pb, and Zn contents of those samples were determined with ICP-Mass. 【Result】 The result showed that there was a rather large difference in effects of the accumulation of Cr, Ni, Cu, As, Cd, Zn in soils under different land use types, except Pb. Based on the assessment compared with background concentrations in soil, the higher accumulation of heavy metals was found in greenhouse and open vegetable field, lesser in maize field and forest field. The order of mean contents of heavy metals in soils was greenhouse＞open vegetable field＞maize field＞forest field. Cd , Cu had relatively serious accumulation in soils compared with Cr, Ni As and Zn. The mean content of Cd in greenhouse was 0.467 mg?kg-1, which exceeded the Grade II of Chinese Soil Quality Criterion GB15618-1995 (6.5＜pH＜7.5) for Cd standard of 0.3 mg?kg-1, and was 5.2 times of Cd in forest field. The mean contents of Cr, Ni, Cu, As, Pb, Zn in soils under four land use types were lower than gradeⅡ of Chinese Soil Quality Criterion. Compared with the age of land use, agricultural chemical compounds application (especial the quality and quantity of applied fertilizer) was the important reason for leading to difference in accumulation of heavy metals in soils under the studied land use types. 【Conclusion】 Heavy metals (Cr, Ni, Cu, As, Cd, Zn) accumulation in soils was significantly affected by land use types, soil in greenhouse accumulates more heavy metals than others. It is suggested that the application of high contents of heavy metals in chemical fertilizer, organic fertilizer and pesticides should be avoided to prevent the accumulation of heavy metal and keep high quality soils for sustainable use.

Key words: soil, land use types, heavy metal elements, accumulation