浙江典型农田土壤有效镉含量特征及其影响因子分析OA

For exploration of the content of available Cd(A.Cd)and its influencing factors in typical farmland of Zhejiang Province,the methods including correlation analysis,multiple linear regression,random forests model,and structural equation model were applied to analyze the data on a total 3564 soil samples on the R platform.The results show that the A.Cd content ranges from 0.001 to 189.000 mg/kg,with a coefficient of variation of 595%,and is lower than the screening value of 0.4 mg/kg for soil pollution risk in agricultural land in 94.8%of the soil samples(pH value 5.0～6.5 of the paddy field).Under scenarios as distinct parent soil,subtype,soil genus,and soil use pattern,the shared soil factors affecting soil A.Cd content are organic matter(OM),pH,available B(A.B),available Cu(A.Cu),available Mo(A.Mo),available Mn(A.Mn),available Fe(A.Fe),and available Zn(A.Zn),with rank by importance as A.B＞A.Cu＞A.Mo＞A.Mn＞A.Zn＞A.Fe.Their relationships with A.Cd are directly or indirectly influenced or regulated by OM,pH,whose relatives could be quantitatively described using a linear regression equation.In the above-mentioned scenarios,the influence of these soil factors on A.Cd content varies,such as A.Cu with the greatest influence in the full sample scenario,the soil developed from neo-neritic sediments of the parent soil,and the soil developed from take-off the latent paddy soil of sub-class,A.B with the greatest influence in the percogenic paddy soils of sub-class,thin-layer mud fields of soil genus,and the rice-rapeseed rotation field of soil use pattern,A.Mn with the greatest influence in the proluvial silt soil of soil genus,and A.Mo with the greatest influence in the soil with single cropping later rice of soil use pattern.