四川邻水县华蓥山—西槽土壤Cu地球化学特征与生态健康

Geochemical characteristics and ecological health-related ranges of Copper in soil in Huaying Mountain-Xicao in Linshui County,Sichuan Province

铜(Cu)是人体所必需的微量元素,目前我国还没有农作物Cu含量的推荐值,更缺少开发富Cu土地资源的土壤Cu含量标准。本文以四川省邻水县华蓥山—西槽耕地区为研究区,根据1∶5万土地质量地球化学调查获取的表层土壤、农作物及根系土中Cu含量数据调查结果,研究了土壤与农作物中Cu的含量及分布特征,分析了玉米籽实Cu生物富集系数(BAF)的影响因素,构建了玉米籽实Cu的BAF预测模型,提出了开发富Cu玉米和富Cu土地资源的Cu含量最佳赋值范围。研究结果显示:①研究区表层土壤Cu含量范围为(3.33~173)×10^(-6),平均值、中位值分别为26.85×10^(-6)、25.60×10^(-6)。土壤Cu高值区主要分布在邻水县华蓥山玄武岩、碳酸盐岩与炭质页岩为成土母岩的地区,土壤Cu低值区分布在西槽侏罗系砂页岩为成土母岩的地区。②研究区玉米籽实Cu含量范围为(0.80~2.71)×10^(-6),平均值为1.76×10^(-6),中位值为1.82×10^(-6)。③为保证人体摄入Cu安全,研究区玉米籽实中Cu含量最佳范围为(0.756~10.080)×10^(-6),土壤中Cu含量最佳范围为(12.67~169.00)×10^(-6)。

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 1∶50000 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.