南京市茶园土壤重金属分布特征及污染评价  

Distribution characteristics and pollution assessment of soil heavy metals in tea garden of Nanjing

作　　者：黄莹[1] 景金泉 肖旭[1] 赵荷娟 文蔚明 马建宏 毛久庚[1] 

机构地区：[1]江苏丘陵地区南京农业科学研究所,江苏南京210046 [2]南京市农产品质量检测院,江苏南京210036

出　　处：《广东农业科学》2017年第10期46-51,共6页Guangdong Agricultural Sciences

基　　金：国家自然科学基金(41501333)

摘　　要：茶园土壤环境质量是茶叶科学种植的一个重要依据。为掌握南京市茶园土壤的酸化程度及重金属污染现状,明确影响南京市茶园土壤环境质量的限制因子,通过GPS定位技术,对南京市不同地区116个典型茶园土壤的pH值及重金属含量进行定位监测与调查。结果表明,南京市茶园土壤存在明显的酸化现象,且呈加重趋势,其中2010—2012年pH 4.1~5.0的茶园土壤为49.1%,比2004—2006年增加29.7%,pH<4的茶园土壤则增加了3.8%。以NY5020-2001《无公害食品茶叶产地环境条件》为依据,采用单因子污染指数法和内梅罗污染指数法对茶园土壤环境质量进行污染评价,结果发现6种重金属元素(Cu、Pb、Cd、Hg、As、Cr)含量均未超过《无公害食品茶叶产地环境条件》中无公害茶园土壤环境质量标准,土壤环境质量评价为清洁。但随着种植年限的增加,Cu、Pb和Cr含量呈上升趋势,且2010—2012年Cu、Pb、Cr含量均超过江苏省土壤背景值,说明它们在茶园土壤中存在一定的积累。相关分析表明,土壤pH值与Cu、Pb、Cr含量呈显著负相关。因此,茶园日常施肥应控制畜禽粪便和含Cr化肥的施用,避免土壤因酸化和含重金属肥料的施入导致重金属含量增加而影响茶叶质量的安全性。Soil environmental quality is an important basis for tea plantation scientifically. To understand the extent of soil acidification,heavy metal pollution characteristics and confirm the factors that influenced soil quality in tea garden of Nanjing,the present study detected soil pH and heavy metal contents via GPS location technique. The results suggested that soil acidification was accelerated in tea garden of Nanjing. From 2010 to 2012,soil pH ranging from 4.1 to 5.0 was 29.7% higher than the pH from 2004 to 2006,accounting for 49.1% of total number of tea gardens.The soil pH less than 4.0 increased by 3.8% . The single factor pollution index method combined with Nemerow pollution index method was used to assess the pollution status of heavy metals on the basis of the Non-Environmental Pollution Food Environmental Condition for Tea Production Area. The results suggested that the contents of heavy metal( Cu,Pb,Cd,Hg,As,Cr) were all below the limit of the Non-Environmental Pollution Food Environmental Condition for Tea Production Area and soil quality were all assessed as clean. However,increased concentrations of Cu,Pb and Cr were observed with prolonged planting. From 2010 to 2012,the average contents of Cu,Pb andCr were higher than the background values of Jiangsu province,suggesting the accumulation of these metals in tea orchard soils. Furthermore,a significantly negative correlation was observed between the contents of Pb,Hg and soil pH by the correlation analysis. Therefore,controlling soil acidification is primarily able to reduce heavy metal bioavailability,and therefore avoid the soil degradation owing to exceeding of Pb and Hg caused by soil acidification.

关 键 词：南京市 茶园 土壤酸化 重金属 污染特征 质量现状分析 

分 类 号：S571.1[农业科学—茶叶生产加工] S151.9[农业科学—作物学]