【作者】 张超兰；

【导师】 徐建明；

【作者基本信息】 浙江大学 ， 土壤学， 2004， 博士

【摘要】 近年来，除草剂的使用已成为农业生产的一种必不可少的手段，因而除草剂大量使用的环境污染问题亦日益突出，如对生态系统的平衡产生威胁性影响，引起农副产品农药含量超标，或者即使不超标也由于食物链的生物富集最终进入人体而危害健康等等。针对除草剂面源污染的特点以及自然土壤中微生物的特性，我们认为通过添加有机、无机营养物质等农业措施激发土壤自然微生物的活性应是行之有效的除草剂污染土壤修复的途径，但这方面的应用基础研究成果在国内外的报道甚少。本研究以弱碱性的莠去津（三氮苯类除草剂）和弱酸性的甲磺隆（磺酰脲类除草剂）两种不同性质的常用除草剂为例，在三种不同性质的水稻土中，通过添加外源有机、无机营养物质，依靠土壤自然微生物活性的提高而快速修复除草剂污染土壤，对提高土壤和水环境的质量，保证农副产品的安全，实现农业可持续发展等有着重要的理论和现实意义。主要研究结果总结如下： 外源营养物质对除草剂污染土壤中表征土壤质量的微生物学指标的影响研究 在实验室条件下，分别研究了除草剂莠去津、甲磺隆污染的三种土壤中微生物生物量碳、氮和磷对外源有机、无机营养物质的动态响应，研究结果表明： （1）莠去津除草剂施入土壤后(22.5kg·ha^-1)，明显降低了三种水稻土中土壤微生物生物量碳、氮和磷的含量。不同土壤中微生物生物量降低程度不同。与空白对照相比，在淡涂泥田中微生物生物量碳、氮、磷分别平均降低了13.51％、10.12％和11.05％；在青紫泥田中分别平均降低了7.35％、6.01％和10.81％；在黄筋泥田中分别平均降低了7.30％、9.75％。甲磺隆除草剂施入土壤后(22.5kg·ha^-1)，也极显著地降低了三种水稻土中土壤微生物生物量碳、氮和磷的含量。与空白对照相比，在淡涂泥田中微生物生物量碳、氮、磷分别平均降低了12.37％、11.79％和11.94％；在青紫泥田中分别平均降低了10.70％、8.43％和13.66％；在黄筋泥田中分别平均降低了8.55％、11.95％（因其酸度较低，微生物生物量磷的测定方法与前两种土壤的不同，所以未测定其中的微生物生物量磷的含量）。 （2）就同一土壤而言，无论是莠去津还是甲磺隆除草剂污染的土壤，添加有机、无机物质均显著提高了土壤微生物生物量碳、氮、磷的含量。其中以添加有机物质对土壤微生物生物量的促进作用大于施用无机物质。在有机物质中以腐熟猪粪的作用最 大，其次是紫云英，影响最小的是水稻秸秆，并且相同有机物质不同施用量对微生物 生物量的影响达到显著水平，施用量越高对微生物生物量提高的促进作用越大，特别 是对土壤微生物生物量碳的影响更明显。添加的无机肥料中以氮磷配合施用对微生物 生物量碳、氮、磷的影响最大，其次是单施氮肥，再次是单施磷肥。但是，随施用量 的增加，‘微生物生物量的增减趋势不一，并且不同施用量之间差异不显著。可见，添 加有机、无机物质可以减缓或消除劳去津、甲磺隆除草剂对土壤微生物的毒害，对除 草剂污染土壤中微生物的恢复起促进作用，提高土壤微生物降解有机污染物的活性， 从而为原位快速生物修复除草剂污染土壤打下基础。 （3）就供试的三种土壤而言，不同土壤中微生物生物量增加幅度不尽相同。总的 来说，在养去津除草剂污染土壤中添加有机、无机物质后，微生物生物量碳增加幅度 在淡涂泥田中为2.59一130.61%;青紫泥田中为7.93⁷1.59%;黄筋泥田中为3，39 105，65%。微生物生物量氮增加幅度在淡涂泥田中为4.26⁵8.11%;青紫泥田中为6.39⁶2.62%;黄筋泥田中为9.65⁹5.10%。微生物生物量磷增加幅度在淡涂泥田 中为12.40¹75.77%;青紫泥田中为3.67¹54.02%。 在甲磺隆除草剂污染土壤中条件有机、无机物质后，土壤微生物生物量碳在淡涂泥稻土中增加幅度为0.23¹13.14%;青紫泥田中为0.30⁴6.48%;黄筋泥田中为1，82⁸3.76%。土壤微生物生物量氮在淡涂泥稻土中增加幅度为4.27一67.87%;青紫泥田中为5.43一58.36%;黄筋泥田中为5.05⁹5.40%。土壤微生物生物量磷在淡涂泥稻土中增加幅度为6.03一139.59%;青紫泥田中为4.09¹41‘26%。 （4）添加有机、无机物质后，劳去津除草剂污染的三种土壤中微生物生物量碳、氮随培养时间变化的趋势基本一致，即0⁷d微生物生物碳、氮降低，但第7d时，添加有机、无机物质的处理中微生物生物量碳、氮均高于仅加养去津的处理和空白对照;7¹4d微生物生物量碳、氮迅速增加;14⁴2d又下降，42d后变化较小。但微生物生物量磷对外源有机、无机物质的动态变化趋势有所不同，施用无机肥料的处理土壤微生物磷比施用有机物质处理的微生物磷先达到最大值，施用有机物料处理的土壤微生物量磷在第14d达到最大值，而施用无机肥料处理的在第7d就已达到了最大值。甲磺隆除草剂污染的三种土壤中微生物生物量碳、氮和磷随培养时间变化的趋势基本一致，与养去津污染土壤中微生物生物量碳、氮和磷随培养时间变化的趋势不同。即O¹.4d微生物生物碳、氮和磷降低，第14d时，添加有机、无机物质的处理中微夕 生物生物量碳、氮均高于仅更多还原

【Abstract】 The wide use of herbicides courses a risk of pollution of the subsoil and consequently contamination of water resources. Atrazine and metsulfuron-methyl are two kinds of herbicides that have been popular used in China.Their physico-chemical and biological behaviors have been evaluated by many researches. However, few researches on effect of addition of organic amendments and fertilizers on microbial biomass and herbicides degradation in soils have been conducted. We took atrazine and metsulfuron-methyl as examples to evaluate their dynamics of degradation in soils and the responses of microbial biomass after application of organic matters and fertilizers. The objectives are to find out the relationship among of organic matters/fertilizers added,, microbial biomass and herbicides degradation, and for remediation of soils contaminated by herbicides. The main results were summarized as follows:Effect of organic matters and fertilizers on microbial biomass in soils contaminated by atrazine/metsulfuron-niethyl herbicides(l)The contents of soil microbial biomass C, N and P significantly decreased after application of atrazine at the rate of 22. 5kg ha-1. Compared with control, microbial biomass C, N and P in soils treated with atrazine were decreased by 13. 51%, 10.12% and 11. 05% in paddy field on desalting muddy polder, respectively; 7. 35%, 6. 01% and 10. 81% in blue clayed paddy, respectively; 7. 30%, 9. 75% in paddy field on quaternary red clay(nodetermination the microbiai biomass phosphorus), respectively. The contents of soil microbiai biomass C, N and P also significantly decreased after application of metsulfuron-methyl at the rate of 22. 5kg ha-1. Microbiai biomass C, N and P in soils treated with metsulfuron-methyl were decreased 12. 37%, 11. 79% and 11. 94% in paddy field on desalting muddy polder, respectively; 10. 70%, 8.43% and 13. 66% in blue clayed paddy, respectively 8. 55%, 11. 95% in paddy field on quaternary red clay(no determination the microbiai biomass phosphorus), respectively.(2)In all three soils contaminated by both atrazine and metsulfuron-methyl, the contents . of microbiai biomass C, N, P increased after addition of organic matters and fertilizers. The higher microbiai biomass was found in treatments with organic matters than that with fertilizers. Among three organic matters added, content of micromial biomass followed the order of decomposed pig manure > Chinese clover > rice straw. The higher application of organic matters coursed the more contents of microbiai biomass. Among fertilizers, contents of microbiai biomass followed the order of N+P>N>P. This suggested that application of organic amendments and fertilizers can reduce the toxicity of atrazine and metsulfuorn-methyl to soil microorganisms, and improved the activities of microorganisms to degrade herbicides.(3)After oraganic amendments and fertilizers were added to the atrazine-contaminated soils, microbiai biomass C in paddy field on desalting muddy polder; blue clayed paddy and paddy field on quaternary red clay increased by 2. 59-130. 61%, 7. 93-71. 59% and 3. 39-105. 65%, respectively. Microbiai biomass N in corresponding soils by 4.26?88.11%, 6. 39-62. 62% and 9. 65-95.10% respectively, and microbiai biomass P by 12. 40-175. 77% and 3. 67-154. 02%(no determinate in paddy field on quaternary red clay), respectively.After organic amendments and fertilizers were added to the metsulfuron-methyl-contaminated soils, microbiai biomass C increased by 0.23-113.14% in paddy field on desalting muddy polder, 0.30-46.48% in blue clayed paddy, and 1.82-83.76%in paddy field on quaternary red clay, respectively, Microbiai biomass N in correspoading soils by 4.27-67.87%, 5.43-58.36% and 5.05-95.40%, respectively, and microbiai biomass P by 6.03-139.59% 4.09-141.26% (no determinate in paddy field on quaternary red clay), respectively.(4)In three atrazine-contaminated soils, the dynamic responses of the microbiai biomassC, N and P with incubation times were similar after application of organic matters and更多还原