Abstract:
Copper (Cu) is an essential trace element for the human body. However, there is no recommended value for Cu content in crops in China, and there is no standardon Cu content in soil for developing Cu-rich land resources. This paper takes the Huaying Mountain-Xicao cultivated land areas in Linshui County, Sichuan Province as the study area. Based on the survey results of the Cu contents in surface soil, crops, and root soil obtained from the ;50 000 land quality geochemical survey, this study investigated the contents and distribution of Cu in soil and crops and analyzed the influencing factors of the biological enrichment coefficient (BAF) of Cu in corn seeds. Moreover, it established a BAF prediction model of Cu in corn seeds and proposed the optimal ranges of Cu contents for developing Cu-rich corn and land resources. The study results are as follows. The Cu content in the surface soil of the study area ranges from 3.33×10
-6 to 173×10
-6, with an average and a median of 26.85×10
-6 and 25.60×10
-6, respectively. The soil with high Cu content is mainly distributed in the areas in Huaying Mountain in Linshui County where basalts, carbonate rocks, and carbonaceous shales are soil-forming rocks. In contrast, the soil with low Cu content is distributed in areas in Xicao where Jurassic sandshaleserves as soil-forming rocks. The Cu content in corn seeds in the study area ranges from 0.80×10
-6 to 2.71×10
-6, with an average and a median of 1.76×10
-6 and 1.82×10
-6 respectively. To ensure the safety of human beings in terms of Cu intake, the optimal Cu contents in corn seeds and soil in the study area should be 0.756×10
-6~10.080×10
-6 and 12.67×10
-6~169.00×10
-6, respectively.