经济发达区不同土地利用方式下土壤中镉的含量特征——以江苏省昆山市为例

CADMIUM ACCUMULATION IN SOILS FOR DIFFERENT LAND USES IN THE DEVELOPED AREAS: A CASE OF KUNSHAN CITY IN JIANGSU PROVINCE

通过对江苏省昆山市高中低产水稻田、菜地、园地和抛荒地等土地利用类型98个土壤样点的检测分析,探讨了不同土地利用方式对土壤镉浓度含量的影响。研究结果表明,高中低产水稻田、菜地、园地土壤镉浓度都超过土壤背景值(0.110 mg/kg)。6种土地利用方式中,低产水稻田土壤的镉浓度最高,其次分别为中产水稻田、园地、菜地、高产水稻田和荒地。与土壤标准值(0.20 mg/kg)相比,中产水稻田有20%样点超标,低产水稻田、园地、菜地分别有18.75%、11.11%、9.09%样点超标,而高产水稻田和荒地没有超标样点。工业废物排放和磷肥的使用可能是影响不同土地利用类型下土壤镉浓度的重要原因,应该引起重视。

Pollution of heavy metals in soil is important for sustainable development, especially in the developed areas, because the soil not only influences the health of people, but also the environment through air and water. To obtain an overview of land use effects on the accumulation of Cd in the soil, 98 samples were collected from Kunshan. The average content of Cd in high-yield, mid-yield, low-yield paddy field, vegetable land, garden land soil samples was higher than the background concentration of soil in Kunshan （0. 110 mg/kg）. The order of the average Cd content was as the followings, low-yield paddy field 〉 midyield paddy field, garden land 〉 vegetable land 〉 high-yield paddy field 〉 uncultivated land. Compared with standard （0.20 mg/kg）, 20%, 18.75%, 11.11% and 9.09% in mid-yield paddy field, low-yield paddy field, garden land and vegetable land soil samples, exceeded the standard limit. According to this investigation, industrial activities and irrigation of sewage were the causes in the accumulation of soil sample Cd.