摘要
在对河南省传统农区分析的基础上,选择4种不同种植模式的农村,采集代表性农田土壤表层混合样品,分析土壤Cr、Ni、Cu、Cd、Pb、As和Zn含量;探讨不同农业种植模式对土壤重金属元素含量带来的影响并进行生态评估。结果表明传统农区表层土壤重金属元素分布受农业生产方式的影响。在同样高投入高产出的背景下,不同种植模式之间有明显差异:传统种植方式和多样化种植方式表层土壤重金属元素残留较低;而专业化单一种植模式下土壤重金属元素残留普遍较高,且高危害性元素明显高于其他种植方式下的村落。在对重金属潜在生态风险评价指标作出相应修改的基础上,对其进行评价比较,得出Cd元素单项潜在生态风险最高且对综合潜在风险指数贡献最大的结论。专业化种植方式的综合潜在生态风险指数较高;传统模式的综合指数最低。内美罗污染指数结果表明,专业化单一种植方式采样村土壤的污染指数明显高于其他2个采样村,且已接近评价指标的清洁(安全)等级上限。综合各分析结果,认为传统模式和多样化模式对土壤环境影响较小,但多样化单位产值较高,因此具有较好的经济和生态效益;专业化种植方式风险较高,虽然单位收益好,但是长期应用易造成重金属元素在土壤中的积累,影响农业生产可持续性。
The article chooses four villages with different crops types based on analysis of rural areas in Henan Province, and analyzed soil concentrations of heavy metal elements chromium, nickel, copper, cadmium, lead, arsenic and zinc of surface soil samples collected from representative farmlands. The paper then discusses the effects crop type differentiation has on soil heavy metal concentrations, and performs ecological assessment on sample sites. Results show that the heavy metal concentrations in surface soils in traditional farmlands are affected by crop types. Given the same high input/output background, different crop types clearly demonstrate different effects. Traditional and diverse cultivation have lower soil heavy metal concentrations, while specialized-cultivation villages have higher concentrations, with high-toxicity elements reasonably higher than other villages. After adjusting the potential ecological risk assessment indices accordingly, analysis performed show that cadmium has the highest single-element potential risk and the biggest contribution to the total potential risk in the area. Specialized villages have a higher potential risk while traditional village have the lowest. Nemerow Pollution Index showed similar results with level for specialized villages reaching the threshold for safe （clean） level. Overall comparison suggests traditional and diverse-cultivation villages are more environmental friendly, diverse-cultivation excels for generating higher income. Specialization has high potential environmental risks. Therefore this practice, though provides a higher income, may increase heavy metal concentrations in farmlands in the long run and jeopardize agricultural sustainability.
出处
《生态环境学报》
CSCD
北大核心
2012年第10期1756-1762,共7页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(41071082)
