摘要
为了揭示设施栽培土壤重金属累积特点及污染风险状况,为沿海设施农区土壤重金属污染的源头消减、生态阻控与风险防范提供科学依据,以近年来高效农业发展迅猛的江苏沿海某设施农地为研究对象,分析了种植方式和棚龄对土壤重金属Pb、Cr、Cd、As全量与有效态含量的影响,探讨了重金属有效态含量与理化性质的相关性,并对设施土壤重金属污染综合潜在生态风险进行了评价。结果表明:目前设施农区土壤环境质量状况整体良好,除重金属Pb含量超过温室蔬菜产地环境质量评价标准值(HJ/T333—2006)外,Cr、Cd和As含量均显著低于参考值;种植方式和棚龄不同程度地影响土壤重金属全量与有效态含量,设施土壤Pb、Cr、Cd全量与有效态含量均显著高于常规大田,且土壤Cd全量与有效态含量随棚龄增加呈现富集特点;土壤Pb、Cr、Cd有效态含量与粘粒含量、阳离子交换量和pH显著负相关,与有机质呈显著正相关,土壤有效态As含量仅与土壤pH显著正相关;目前研究区设施土壤重金属污染处于轻度综合潜在生态风险程度,综合潜在生态风险指数呈现出青椒大棚>西瓜大棚>韭菜大棚的趋势,且综合潜在生态风险指数随棚龄的增加而升高。
Greenhouse soils have different biogeochemical characteristics from natural soils. Therefore, it is important to reveal the accumu- lation and ecological risks of soil heavy metals for sustainable production of greenhouse soil. This study was carried out to examine the ef- fects of cropping methods and greenhouse ages on the total and bioavailable content of soil heavy metals（Pb, Cr, Cd, As ）, in a coastal greenhouse area in Jiangsu Province, China, a rapid development area of high-efficiency agriculture. Results indicated that soil environ- mental quality across the greenhouse area was generally in good condition. Except Pb whose content exceeded the environmental quality standard for farmland of greenhouse vegetables production（HJ/T 333--2006 ）, the content of Cr, Cd and As was lower than the environmen- tal quality standards. Cropping methods and greenhouse ages affected the total and bioavailable content of soil heavy metals to a different extent. Total and bioavailable concentrations of Pb, Cr and Cd in greenhouse soil was significantly higher than those in conventional field. The total and bioavailable content of Cd exhibited the trend of accumulafion with increasing greenhouse ages. The bioavailable Pb, Cr, andCd in soil showed significant negative correlations with soil clay particle content, cation exchange capacity, and pH, but positive correlations with soil organic matter. The bioavailable As was merely positively correlated with soil pH. The comprehensive potential ecological risks of heavy metals were currently at a low level across the whole greenhouse area. The indexes of the comprehensive potential ecological risks in different crop greenhouses were in order of green pepper〉watermelon〉Chinese chives, increased with increasing greenhouse ages. The re- search findings could provide scientific reference for pollution source reduction, ecological activity control and risk prevention of soil heavy metals in the coastal greenhouse area.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2016年第8期1498-1506,共9页
Journal of Agro-Environment Science
基金
江苏省科技支撑计划社会发展项目(BE2014678)
江苏省自然科学基金面上项目(BK20141266)
国家自然科学基金项目(41571223)
关键词
沿海
设施土壤
重金属
有效态
生态风险
coastal area
greenhouse soil
heavy metal
bioavailability
ecological risk
