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Microbial Activity Indices: Sensitive Soil Quality Indicators for Trace Metal Stress 总被引:8,自引:0,他引:8
LI Yong-Tao T. BECQUER C. QUANTIN M. BENEDETTI P. LAVELLE DAI Jun 《土壤圈》2005,15(4):409-416
Physicochemical properties, total and DTPA (diethylenetriaminepentaacetic acid)-extractable Cu, Zn, Pb and Cd contents, microbial biomass carbon (C) content and the organic C mineralization rate of the soils in a long-term trace metal-contaminated paddy region of Guangdong, China were determined to assess the sensitivity of microbial indices to moderately metal-contaminated paddy soils. The mean contents of total Cu, Zn, Pb and Cd were 251, 250, 171, and 2.4 mg kg^-1 respectively. DTPA-extractable metals were correlated positively and significantly with total metals, CEC, and organic C (except for DTPA-extractable Cd), while they were negatively and highly significantly correlated with pH, totall Fe and Mn. Metal stress resulted in relatively low ratios of microbial biomass C to organic C and in remarkable inhibition of the microbial metabolic quotient and C mineralization rate, which eventually led to increases in soil organic C and C/N. Moreover, microbial respiratory activity showed a stronger correlation to DTPA-extractable metals than to total metal content. Likewise, in the acid paddy soils some “linked” microbial activity indices, such as metabolic quotient and ratios of basal respiration to organic C, especially during initial incubation, were found to be more sensitive indicators of soil trace metal contamination than microbial biomass C or basal respiration alone. 相似文献
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庄河市是东北地区主要的草莓生产基地,借助自然资源条件和政府的政策扶持等优势,庄河草莓成长为年产量10万t、年产值10亿元的区域品牌。该研究根据在北京、沈阳、大连的问卷调查数据,分析庄河草莓区域品牌建设情况,结果表明:消费者对庄河草莓的品牌印象和评价一般,庄河草莓面临的竞争对手多而强大,消费者高度关注产品质量和安全,消费者对庄河草莓的知晓途径主要是口口相传,新闻媒体和广告传播的作用不明显。根据庄河草莓发展区域品牌的内在条件和优势,提出了加强品牌的协同管理,打造统一品牌,发展依托农业旅游和休闲娱乐的品牌经营模式,依靠质量建设提高品牌经营力,构建现代营销传播体系,深化政策支持的品牌发展对策。 相似文献
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地理标志农产品作为优质农产品的代名词,深受消费者青睐,社会重视度逐年增强。其品牌化建设能够凸显品牌效应,促使区域内产业集聚,推动区域经济发展。该研究依托地理标志产品兴起的企业品牌对农产品品牌发展的重要影响,基于原产地居民认知视角分析地理标志品牌知名度、企业品牌知名度的现状以及影响因素,探讨集群品牌与企业品牌的关系,提出相应的品牌建设思路。 相似文献
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为找到水体富营养化氨氮浓度指标的指示性生物,研究不同浓度(0.2 mg/L、0.5 mg/L、1mg/L、2mg/L、4mg/L、8mg/L、16mg/L)氨氮(NH_4~+-N)对黑藻(Hydrilla verticillata)生长(株高、分支、鲜重和死亡率)的影响。结果表明:低浓度(0.2mg/L、0.5mg/L、1mg/L)氨氮促进黑藻生长,高浓度(2mg/L、4mg/L、8mg/L、16mg/L)氨氮抑制黑藻生长,且浓度越高抑制作用越明显,浓度为4~16mg/L的氨氮导致黑藻死亡,且浓度越高死亡率越大,当浓度为16mg/L时,试验至第4周黑藻全部死亡。野外调查发现,黑藻为优势物种的河段,其水质氨氮浓度不超过1mg/L,黑藻为消失性物种的河段,其水质氨氮浓度不低于4mg/L。室内培养结果与野外调查结果一致,因此,黑藻可以作为水质氨氮浓度的指示性生物。 相似文献
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通过对代用茶现有标准的梳理、不同标准间的比较,解读绿色食品代用茶标准制修订的编制过程以及标准在实施过程中容易出现和存在的问题,通过发现问题,给生产者提出建议,便于生产出符合国家食品安全标准和产品标准的代用茶产品,满足消费者的质量安全需求。 相似文献
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