苏南经济快速发展区土壤有效态钴含量影响因素及分布特征

以江苏省昆山市为典型区,研究农田土壤有效态Co含量的影响因素及分布特征。结果表明:(1)全Co含量平均值为12.58 mg/kg,高于全国平均值11.2 mg/kg,变异系数为13.59%;土壤有效态Co含量为0.05~0.80 mg/kg,平均值为0.26 mg/kg,变异系数为81.63%;土壤Co活化率平均值为2.17%,变异系数为94.24%。(2)在土壤全Co含量变异较小的情况下,土壤有效态Co和土壤Co的活化率与pH值呈极显著负相关,均以指数模型拟合更优;回归分析表明,pH值是影响土壤有效态Co含量和土壤Co活化率的主要因素,说明研究区内土壤酸化直接导致土壤有效态Co含量增加。(3)全Co含量在不同的经济功能区和不同的地貌区差异均不显著;有效态Co含量和土壤Co的活化率在菜地区极显著地高于化工区和印染造纸区;有效态Co含量和土壤Co的活化率以南部湖荡区较高,南部湖荡区土壤有效态Co极显著地高于中部平原区。(4)土壤有效态Co含量及Co的活化率在土壤剖面上均以表层为高。

Influencing Factors and Distributing Characteristics of Soil Available Cobalt in the Region with High Economy Development of South Jiangsu Province

The influencing factors and distributing characteristics of soil available cobalt in Kunshan City of Jiangsu Province were studied.The results show that:(1)The average of soil total Co is 12.58 mg/kg,it is higher than the average of China,which is 11.2 mg/kg,the coefficient variance of soil total Co is 13.59%.The soil available Co ranges from 0.05 mg/kg to 0.80 mg/kg,and the average is 0.26 mg/kg,the coefficient variance is 81.63%.The average of the available rate of soil Co is 2.17%,and the coefficient variance is 94.24%.(2)With the small coefficient variance of soil total Co in this study,soil available Co and available rate of soil Co are extremely significantly negative correlated with soil pH,exponential model is more suitable to explain the relationship between them,the regression analysis shows that pH is the most important factor for soil available Co and the available rate of soil Co,soil acidification induces the increasing of soil available Co.(3)The content of soil total Co has no obvious difference among different economy function area and different physiognomy in this city,the total content of soil Co of vegetable area is relatively higher among different econ omy function areas,the content of the south area is relatively higher among different physiognomy area.Soil available Co and available rate of soil Co of vegetable areas are extremely significantly higher than these of chemical factory areas and printing,dyeing,and paper-making areas,soil available Co and available rate of soil Co of the south areas is high,and soil available Co of the south areas is extremely significantly higher than that of the middle area,available rate of soil Co has no obvious difference among different physiognogmy areas in Kunshan City.(4)Soil available Co and available rate of soil Co are relatively higher in the upper layer in soil profiles.