An analysis of differences in accumulation of heavy metals in main crops in a tin mining area of Yunnan Province

Different enrichment capabilities of heavy metals between maize and pomegranate have important significance for guiding and adjusting agricultural products in the polluted land. Based on collecting soil and plant samples, the authors analyzed different enrichment coefficients of heavy metals between corn and pomegranate. Some conclusions have been reached: ①The average standard rate of Cr, Pb, Cd and As in pomegranate samples is 3.70%, 25.93%, 74.07% and 7.41% respectively, and the average standard rate of Cr and Pb in corn sample is 3.7% and 22.22% respectively. The standard-surpassing phenomenon of heavy metals in pomegranate is more obvious than that in maize, and the enrichment capability of pomegranate for Cd, Pb, As is obviously higher than that of maize;②As for heavy metal content of different soils, the standard-surpassing phenomenon of pomegranate is more obvious than that of maize. Pomegranates can enrich more Cd, Cr, Pb and As than maize except for Cr. Especially in low heavy metal content soil, the standard-surpassing phenomenon of pomegranate is significantly higher than that of maize. It is thus held that pomegranate can absorb more Cd, Cr, Pb, As than corn in soils suffering the same heavy metal pollution and that, from the angle of the safety of edible agricultural products, the local government should optimize the layout of agricultural production and grow more maize and less pomegranate.