【作者】 张晓萍；

【导师】 宗良纲；

【作者基本信息】 南京农业大学 ， 环境科学， 2008， 硕士

【摘要】 我国是世界上中药材生产大国,但由于中药材生产基地土壤重金属污染日益严重,中药材的安全问题引起各界的广泛关注。本文通过实验室解吸试验和生物盆栽试验相结合的方法研究了不同调控措施对Cd污染土壤上菊科植物生长及其品质安全的影响,阐述食品安全生产与土壤环境质量的关系,探讨在污染土壤上通过适当的调控措施达到既能保持一定的产量水平,同时又能抑制土壤重金属从土壤向作物体内转移,为中药材产业的健康发展提供技术参考。本文主要研究内容包括三方面:（1）磷对土壤Cd解吸作用的影响因素分析;（2）不同施肥措施对Cd污染土壤上菊花生长及其品质安全的影响;（3）有机肥、生态肥及膨润土对Cd污染土壤上菊花脑生长及其品质安全的影响。通过解吸试验分析了溶液中磷浓度、溶液pH条件、支持电解质浓度以及土壤类型对磷解吸土壤重金属Cd的影响作用。结果表明:在存在磷的解吸系统中,磷浓度的大小对黄棕壤Cd的解吸没有显著影响。解吸液Cd浓度随pH的降低而逐渐上升,并随支持电解质浓度的升高而升高,相关系数都达0.9700以上,并且其相关性达到显著水平,表明介质pH和支持电解质浓度是影响磷解吸土壤中Cd的重要因素。对磷解吸土壤Cd的影响规律也因不同土壤类型而异.砖红壤、紫色土、黄棕壤Cd的解吸能力明显高于黄壤、红壤和潮土,并且随着磷浓度的增大,砖红壤解吸液中的Cd浓度逐渐减小,紫色土、潮土规律恰相反。另外,红壤和黄壤没有明显差异。因此,在Cd污染土壤上采用磷肥作为改良剂时,需考虑污染土壤的类型,并不是所有Cd污染土壤增施磷肥都能达到良好的改良效果。磷源的不同其效果也不一样。单施钠磷虽能提高菊花根系活力,降低菊花叶片Cd含量,同时会降低菊花叶片叶绿素含量,但对菊花酶活性、蛋白质含量影响不大。钙磷在蛋白质含量、根系活力和叶绿素含量指标上的效果优于钠磷。有机肥能增强菊花根系活力,有利于叶绿素合成,提高菊花产量和蛋白质含量。除钙磷和有机肥的配合施用下根系活力指标较单施钙磷的效果差外,不同磷源和有机肥的配施处理发挥了磷素和有机肥各自的优点,均比单独施用方式的效果好。通过菊花脑盆栽试验,研究了有机肥、生态肥、膨润土及生态肥与有机肥的配施对Cd污染土壤上菊花脑生长、土壤中Cd形态变化和菊花脑体内Cd积累的影响。结果表明,有机肥、生态肥及膨润土都能提高菊花脑生物量、叶片叶绿素含量、蛋白质含量及POD、CAT酶活性,且在菊花脑不同生长阶段嫩叶Cd含量表现出前期较低后期有逐步积累的趋势,建议食用上市前期的嫩叶。生态肥及有机肥处理都不同程度的降低了土壤交換态Cd含量,但促进菊花脑对Cd的积累,威胁到食品安全。膨润土降低了菊花脑体内Cd含量和土壤交换态Cd含量,且两者呈正相关关系,且施用量为15g·kg^-1时改良效果最佳。更多还原

【Abstract】 Chinese medicinal materials are well-known in the world. Unfortunately, they were contaminated by heavy metals due to production places polluted by heavy metals, the society paid a high attention on the issue of Chinese medicinal materials safety. By desorption and pot experiments, the effects of different adjustment measures on compositae growth and its quality on Cd polluted soil were investigated. This paper deeply understood the relationship between food safety production and soil heavy metals pollution. The study took some treatments in order to discuss how to inhibit the metastasis of heavy metals from soil to plant and keep a certain yield level, which offered technology reference to health development of traditional Chinese medicine industry.This study included three sections:（1）Effects of Phosphorus on Cd desorption from soils;（2）Effects of different fertilization measures on Chrysanthemum growth and its quality on Cd polluted soil;（3）Effects of organic fertilizer, ecological fertilizer and bentonite on Chrysanthemum nankingense hands’ growth and its quality on Cd polluted soil.Effects of phosphorus on Cd desorption from contaminated soils were studied. The test result indicated that different phosphorus concentration had little effect on Cd desorption from yellow brown soil. Cd concentration in desorption solution increased with the decreasing of pH medium and increasing of concentration of electrolyte, and very significant positive correlation appeared between them（their correlation coefficients r were over 0.9700）.Accordingly, pH medium and concentration of electrolyte were important factors affecting phosphorus on Cd desorption from soil. Effects of different soil types on phosphorus on Cd desorption from soil were disaffinity. The ability of Cd desorption from latosol, purple Soil and yellow brown soil was superior to yellow soil, red soil and alluvial soil. Cd concentration in desorption solution of latosol decreased as the phosphorus concentration increased, but the law of purple soil and alluvial soil was just on the contrary. Besides, there was no significant difference on red soil and yellow soil. Therefore, when phosphate fertilizer as improver is adopted on Cd contaminated soil, soil types must be considered, not applying phosphate fertilizer on all of Cd contaminated soils has a good effect.Pot experiment was carried out to study the effects of Na phosphorus, Ca phosphorus, organic fertilizer, Na phosphorus-organic fertilizer and Ca phosphorus-organic fertilizer on chrysanthemum’s growth and its quality on Cd polluted soil. The results showed that the improvement effects varied with the different fertilizer due to their different characters and mechanisms. Root activity was improved and Cd content in leaves decreased with the Na phosphorus treatment, but the chlorophyll content in leaves was decreased simultaneously and there was no significant effect on the activity of enzyme and protein content. Ca phosphorus treatment was superior to Na phosphorus treatment in indexes of protein content, root activity and chlorophyll content, but no significant difference was occurred between the two phosphorus treatment in other indexes. Organic fertilizer treatment increased chrysanthemum’s flower yield, which rose 80 percent compared to the CK treatment. Chlorophyll content, protein content and root activity also got a rise with the Na phosphorus treatment. Combined application of Ca phosphorus with organic fertilizer was better than independent application of Ca phosphorus, except root activity index. Combined application of Na phosphorus with organic fertilizer was more effective than independent application of the organic fertilizer and Na phosphorus in all of indexes, which had best improvement effects among experiments.Pot experiment was carried out in Cd contaminated soil to investigate the effects of organic fertilizer, ecological fertilizer, combined application of them and bentonite on chrysanthemum nankingense hands’ growth, uptake of Cd by chrysanthemum nankingense hands and fractions of soil Cd. Results indicated that organic fertilizer, ecological fertilizer and bentonite increased the chrysanthemum nankingense hands yield, chlorophyll content, protein content and the activity of the enzyme（POD,CAT）.The content of Cd in edible parts of chrysanthemum nankingense hands was depressed at first, then elevated slowly, the results suggest eating the prophase growing chrysanthemum nankingense hands’ tender leaf on Cd polluted soil.. Organic fertilizer and ecological fertilizer application decreased the exchangeable form of Cd content in soil, but increased the content of Cd in chrysanthemum nankingense hands, which might be harmful for food safety. Bentonite treatment decreased the content of Cd in chrysanthemum nankingense hands and EXC-Cd content in soil, and there was a positive correlation between them. When the use of bentonite was 15 g·kg^-1, the improvement effects had the best result.更多还原