苏南经济快速发展区昆山市土壤铅形态含量及其影响因素

Quantitative analysis of factors influencing soil Pb content in the high economic development region of South Jiangsu Province: a case study in Kunshan City

以地处苏南经济快速发展区的江苏省昆山市为典型区,采集水稻土及传统蔬菜地和保护栽培蔬菜地土壤样品126个,采用多元统计回归分析方法,定量研究几种因素对农田土壤各形态铅含量的影响。结果表明:土壤有效态铅平均含量为3.75 mg·kg-1,土壤全铅平均含量为27.42 mg·kg-1,土壤铅的活化率平均为15.64%。土壤各形态铅含量相对大小为残渣态(15.35 mg·kg-1)>有机质结合态(6.68 mg·kg-1)>铁锰氧化物结合态(4.27 mg·kg-1)>碳酸盐结合态(0.76 mg·kg-1)>可交换态(0.36 mg·kg-1),残渣态含量明显高于其他形态,占49.79%。pH是影响可交换态铅含量和铁锰氧化物结合态铅含量的最主要因素,均达极显著负相关水平。全铅含量是影响碳酸盐结合态铅含量和残渣态铅含量的最主要因素,达极显著正相关水平。有机质含量是影响有机质结合态铅含量的最主要因素,达极显著正相关水平。pH也是影响有机质结合态铅含量的重要因素。

One hundred and twenty-six soil samples were collected from paddy field, traditional vegetable and protected vegetable fields in Kunshan City, a typical area of the high economic development region of South Jiangsu Province. Multi-statistics regression analysis was used to quantify the factors influencing soil Pb forms in the studied area. The results showed 1.04-12.04 mg.kg-1 of soil available Pb, with an average value of 3.75 mg.kg-1. While the average content of soil total Pb was 27.42 mg.kg-1, the available rate of soil Pb was 15.64%. The order of contents of different forms of soil Pb was as follows： soil residue Pb （15.35 mg.kg-1） 〉 soil organic-matter bonded Pb （6.68 mg.kg-1） 〉 soil iron/manganese-oxide bonded Pb （4.27 mg.kg-1） 〉 soil carbonate bonded Pb （0.76 mg.kg-1） 〉 soil exchangeable Pb （0.36 mg.kg-1）. Soil residue Pb content was significantly higher （49.79%） than the contents of the other forms of soil Pb. pH was the most important factor affecting soil exchangeable Pb and iron/manganese-oxide bonded Pb con- tents, it was significantly negatively correlated with contents of the two forms of soil Pb. Soil total Pb content was the most important factor for soil carbonate bonded Pb and residue Pb contents, both of which had significant positive correlation. Soil organic-matter content was the most important for soil organic-matter bonded Pb content, and both had significant positive correlation, pH was also an important factor for soil organic-matter bonded Pb content.