Abstract:Insufficient or excess heavy metals in soils seriously affect the healthy growth of citrus.It is necessary to establish an accurate space model which can effectively reflect the spatial distribution of heavy metals content.This paper took the citrus production areas in Honghuatao county,Yidu City,Hubei Province were used to study heavy metal Cu in soil.Soil factors including total K,total Cr,CEC,total Pb and total N (P<0.05) closely correlated with Cu were chosen as the spare variables through Pearson’s correlation coefficient method.Total scores were calculated by principle components analysis (PCA) method and used as auxiliary variables to reduce the dimension and redundancy of original variables.Three spatial interpolation models including ordinary Kriging (OK) model,ordinary Cokriging (COK) models which took total scores (COKPCA) and total K (COKK) as auxiliary variable were constructed.The optimal space model was proposed by comparing the prediction accuracy of the models (OK,COKK,COKPCA).The most suitable model was used to predict spatial distribution of Cu in the area studied.The results showed that RMSE of OK,COKK and COKPCA models were 7.044,6.907 and 6.309,with R2 of 0.716,0.743 and 0.852,and AIC of 101.591,96.908 and 87.203,respectively.Interpolation results were comprehensively compared.COKPCA was found to be the best simulating model,followed by COKK but OK was poor.It will provide reference for accurately simulating soil heavy metals Cu in the small-scale area and a scientific basis for modern agricultural production and fine management of agriculture.