土壤性质对其吸附莠去津和灭草松性能影响的多元统计研究

Investigation of effects of soil properties on atrazine and bentazone absorption using multivariate analysis

【目的】研究土壤性质与其吸附农药性能之间的关系,揭示控制土壤吸附极性农药的关键因素。【方法】采用平衡振荡试验测定了莠去津和灭草松在6种不同性质土壤上的吸附等温线。用聚类分析定性研究了土壤性质与莠去津和灭草松土壤吸附等温线常数之间的关系;通过主成分分析得到3个描述土壤性质的主成分,然后用逐步回归方法建立农药土壤吸附常数与主成分之间的线性多项式模型;进一步结合因子旋转和相关分析得到影响土壤吸附莠去津和灭草松的关键因素。【结果】莠去津和灭草松在性质相似的土壤上的吸附常数相近;莠去津在土壤中的吸附常数Kf与土壤性质的第1主成分(土壤有机质、粉粒含量以及pH有关)线性相关,而灭草松在土壤/溶液间的分配常数Kd与土壤性质的第1和第2主成分(阳离子交换容量、比表面积、pH有关)线性相关;有机质和pH是影响土壤吸附莠去津的关键因素,有机质、pH和土壤表面性质是影响土壤吸附灭草松的关键因素。【结论】聚类分析、主成分分析可以用来系统地研究土壤性质与土壤吸附农药性能之间的定性、定量关系。

[Objective] The study was done to gain a better understanding of the impact of soil physical and chemical properties on herbicides sorption.[Method] The batch equilibrium method was employed to determine adsorption isotherms of atrazine and bentazone on six soils with various properties.Based on soil properties and adsorption isotherms,the Q-mode hierarchical cluster for soils was employed to qualitatively identify the relationship between soil characteristics and absorption of herbicides,bentazone and atrazine,to soils.Data of seven soil property variables in six soils were reduced by principal component analysis,and the three principal components were extracted.The extracted principal components were then correlated with herbicide absorption coefficients using stepwise multiple linear regression.In addition,the equamax rotation and correlation analysis were further carried out to find the factors which dominated the absorption of herbicides in soils.[Result] Soils with the similar properties have closer absorption isotherm parameters for a given herbicide.The absorption coefficients of atrazine are linearly correlated with the first principal component,while those of bentazone are linearly correlated with the first and second principal components simultaneously.The results further revealed that the soil organic matter,pH,and the surface charge are mainly responsible for the absorption of bentazone in soils,and soil organic matter and pH are the main factors which controll the absorption of atrazine to soils.[Conclusion] This study shows that hierarchical cluster and principal component analysis provide the potential approaches to study the relationship between soil characteristics and its absorption capacity of herbicides.