海南香蕉园土壤中重金属现状及变化趋势分析

为了解香蕉种植园土壤重金属含量及香蕉种植尤其是施肥对土壤重金属含量的影响,采集海南岛5大香蕉种植区(儋州、临高、东方、乐东、昌江)各大香蕉基地的共计49个蕉园土壤样品及与之对应的18个对照样品,分析了Zn、Cu、Hg、Cd、Pb及Ni的含量.研究表明,相对于对照土壤,全区蕉园土壤Zn、Cu、Ni含量增加(Cu上升0.02～24.24mg/kg,Zn上升6.3～58.2 mg/kg,Ni上升2.81～6.40mg/kg);Cd、Hg含量增加较少(Cd上升0.09～0.45 mg/kg,Hg上升0.01～0.04mg/kg);Pb有下降趋势(下降0.32～7.88 mg/kg).与我国土壤环境质量标准相比,蕉园土壤中Cu、Zn、Hg、Pb含量为二级,而79.6%土壤样品的镉含量和24.3%土壤样品的镍含量高于相应二级标准.

Present situation of soil heavy metals in banana gardens of Hainan and its changing tendency

The present paper is concerned with the current situation of the heavy-metal content of soil in Hainan's banana plantations and its changing trend.In hoping to expose the effect of the banana cultivation,especially the fertilizer application on the heavy-metal content,49 soil samples from the banana plantations and 18 contrast samples have been collected from the following five areas, i.e.,Danzhou,Lingao,Dongfang,Ledong and Changjiang.The content of Cu,Zn, Hg,Cd,Ni and Pb in the above samples has been analyzed.As a result,for the banana cultivation soil,the content of Cu has increased by 0.02-24.24 mg/kg; while Zn is by 6.3-58.2 mg/kg;Ni is raised by 2.81-6.40 mg/kg whereas Cd is by 0.09-0.45 mg/kg.At the same time,Hg has increased by 0.01-0.04 mg/kg;however,Pb has lowered by 0.32-7.88 mg/kg.Comparing the analytic data to the state soil environment quality standard,the content of Cu,Zn,Hg and Pb can be taken as below the second level.But with Cd,the content of 79.6% in the plantation samples and Ni content of 24.3% with the samples higher than that of the corresponding second state level.But,generally speaking,except some few areas,the content of Hg,Pb and Ni remains within the safe scope of the pollution tolerance,but the content of Cd remains higher than the contrasted soil,which suggests necessity for profound studies in the future.