【作者】 赵长山；

【导师】 马凤鸣；

【作者基本信息】 东北农业大学 ， 作物栽培学与耕作学， 2007， 博士

【摘要】 化学除草技术从产生、应用、发展到现代，在提高作物产质量的同时，也带来了一系列的环境问题。20世纪80年代后，磺酰脲类、咪唑啉酮类等超高活性除草剂的开发应用占据农药市场，咪唑乙烟酸、氯嘧磺隆、异噁草酮是此类超高活性除草剂中的代表品种，是中国春大豆产区广泛应用的三种长残留性除草剂。此类长残留性除草剂长期大量应用，不仅危害后茬敏感作物，也势必会造成对大豆根圈环境的破坏。因此，深入开展咪唑乙烟酸、氯嘧磺隆、异噁草酮对大豆根圈环境影响的研究，明确长残留性除草剂对大豆根系生长环境的影响程度，为通过人工措施调节大豆根圈环境，促进根圈环境中营养物质的转化和大豆对根圈环境中营养物质的吸收与利用奠定理论基础，从而实现大豆高产优质。本文在研究大豆田常用的三种长残留性除草剂咪唑乙烟酸、氯嘧磺隆和异噁草酮对大豆根圈环境影响基础上，利用生物措施修复受该类长残留性除草剂伤害的大豆根圈环境，得出如下结论：1．咪唑乙烟酸使细菌数量显并增加，真菌数量表现为短时间内增加，而后受到明显抑制；放线菌数量短时间增加，以后逐渐恢复至正常田间状态。氯嘧磺隆施用后，土壤中细菌数量显著减少，但真菌数量显著增加，放线菌短时间内增加，但随时间的延长而减少。异噁草酮对大豆根圈细菌具有较长时间的刺激作用，且随着异噁草酮用量增加刺激作用增强；土壤中异噁草酮含量较高时，短时间内土壤中真菌数量增加，但随用药后时间的延长而减少。异噁草酮止常田间用量2250g／hm~2条件下土壤中真菌的数量减少，但高用量时，放线菌增加。2．咪唑乙烟酸、氯嘧磺隆施用后大豆根瘤数明显减少，鲜重、干重下降。减少比例随用药量的增加而增加。异噁草酮施药量为2250g／hm~2对大豆根瘤没有影响，施药量为2500g／hm~2利2750g／hm~2时，大豆根瘤数明显减少，鲜重、干重下降。3．咪唑乙烟酸对大豆根圈三种土壤酶活性影响表现为：脲酶活性严重受抑制，用药量增加抑制作用加强，但35天后，活性恢复正常：纤维素酶的活性显著提高，但随着时间的延长而逐渐恢复到正常水平；磷酸酶活性短时间内提高，更长时间表现为抑制作用。氯嘧磺隆对大豆根圈三种土壤酶活性影响表现为：脲酶活性显著受抑制：纤维素酶活性显著增高；磷酸酶活性短时间提高，很快开始显著下降。异噁草酮对大豆根圈三种土壤酶活性影响表现为：脲酶活性表现为先下降后提高的规律：纤维素酶活性28天内显著提高以后逐渐恢复；磷酸酶活性施药后21天内显著提高，以后恢复至正常。4．降解菌IZP-1对咪唑乙烟酸的降解作用最初有12小时的停滞期，12小时后开始迅速降解，至72小时降解90％以上。葡萄糖、乳糖、蔗糖、麦芽糖、柠檬酸钠作为碳源加入培养基中，使停滞期延长至24小时，但对最终的降解作用无积极影响。25℃为最佳降解温度，pH5-7有利于降解菌降解作用。降解菌YW-1对氯嘧磺隆的降解作用没有表现出明显的停滞期，降解速度平稳，36小时降解40％，96小时后残留率趋于0。降解菌YW-1的最适生长条件为30℃，pH5.0。外加碳源对降解作用没有影响。30℃为最佳降解温度。pH5—7有利于降解菌的降解作用。降解异噁草酮的混合菌CZ-1+CZ-2可对异噁草酮彻底降解，而且没有明显的停滞期，36小时降解90％，48小时便完全降解。外加碳源后出现36小时的停滞期，以后降解迅速。最佳降解温度为25℃-30℃，pH8-9的碱性条件有利于降解作用。5．降解菌IZP-1能够部分修复咪唑乙烟酸对大豆根瘤个数及鲜干重影响，用药量越低被修复的最终结果越好。降解菌YW-1能部分修复氯嘧磺隆对大豆根瘤数量及鲜干重的影响。降解菌CZ-1+CZ-2能完全修复中低用量的异噁草酮对大豆根瘤个数、鲜重和干重的影响，但高用量不能完全修复。6．IZP-1施用后，能降低咪唑乙烟酸对真菌生长的刺激作用，施用后早期真菌数量明显减少，7月中旬后真菌数量开始增加。IZP-1施用后，土壤中放线菌数量持续增加并始终高于对照。IZP-1能够部分修复咪唑乙烟酸对真菌和放线菌的影响。YW-1施用后，土壤中真菌数量有所减少，但较对照真菌数量增加。YW-1可使大豆根圈土壤中放线菌数量增多，促进了放线菌的生长和繁殖。YW-1对放线菌和真菌数量变化有部分修复作用。CZ-1+CZ-2施用后，可使异噁草酮增加的真菌数量降低，但仍高于对照，只能起到部分修复的作用。CZ-1+CZ-2可使大豆根圈土壤中放线菌数量变化更为平稳，能够起到部分修复作用。7．降解菌IZP-1施用后，能够完全修复咪唑乙烟酸对大豆根圈土壤脲酶、纤维素酶、磷酸酶活性的影响，而且在咪唑乙烟酸对这三种酶没有影响时，没有副作用。降解菌YW-1施用后，能够部分修复氯嘧磺隆对大豆根圈土壤脲酶、纤维素酶、磷酸酶的活性，不能完全修复，但无副作用。降解菌CZ-1+CZ-2降解菌施用后，能够部分修复异噁草酮对大豆根圈土壤脲酶、纤维素酶、磷酸酶的活性，不能完全修复。咪唑乙烟酸、氯嘧磺隆、异噁草酮对大豆根圈土壤脲酶、纤维素酶、磷酸酶活性的影响在7月中旬以后都能够得到自然恢复，降解菌只能在此期以前发挥修复作用。更多还原

【Abstract】 Soybean is not only an important food crop in china, but also a characteristic oil crop inHeilongjiang province. Soybean yield plays an important role in Chinese national economydevelopment and people’s daily life. Crop yield and quality had been increased as using chemicalweed control technology, at the same time it also led to a series of environmental problems.Development and application of some kinds of super-high efficient herbicides such as sulfonylurea,imidazolinones occupied the herbicide market after the 80’s in 20 centuries. Imazethapyr,chlorimuron-ethyl and clomazone were the representative sorts and were widely applied in springsoybean produce areas in China. Such kinds of long residue herbicides applied in soybean field didnot only injure the succeeding susceptible crops, but also destroyed the environment of soybeanrhizosphere deeply. Studies on the influence of Imazethapyr, chlorimuron-ethyl and clomazone onsoybean rhizosphere will nail down effect of long residue herbicides on soybean rhizosphereenvironment, and make theory foundation regulating the environment of soybean rhizosphere toaccelerate nutritive material translation and its absorption through measure, so as to realize highyield and quality of soybean. This paper studied the influence of three long residue herbicidesImazethapyr, chlorimuron-ethyl and clomazone on soybean rhizosphere environmnent and its in-situbioremediation for the destroyed environment of soybean rhizesphere by the long residueherbicides. The results of the experiment were as follows:1. After applying imazethapyr, the bacteria population increased significantly, the fungi’sincreased in short time, and then inhibited, and the actinomycetes’ also increased in short time, andgradually recovered to the normal level.After applying chlorimuron-ethyl, The bacteria population decreased significantly, and thefungi’s increased significantly, the actinomycetes’ increased in a short time, but subsequentlydecreased in soybean rhizesphere soil.The herbicide clomazone stimulated bacteria of soybean rhizesphere for a long time, and themore of application dose, the greater of the stimulative effects. If clomazone content in soil washigher, the fungi number increased in short period and subsequently decreased. Under the normalapplication dose 2250g/hm~2, the fungi decreased, but the actinomycetes increased under higher application dose.2. After applying imazethapyr, chlorimuron-ethyl, the amount, fresh and dry weight ofsoybean nodule distinctly decreased. The more the application dose was, the bigger the decreasedproportion was. There was not influence on soybean nodule when clomazone application dose was2250g/hm~2, but the amount, fresh and dry weight of soybean nodule distinctly decreased atclomazone 2500g/hm~2 and 2750g/hm~2.3. The influence of imazethapyr on three soil enzymes showed that soil urease activity wasseriously inhibited and this inhibition increased as application dose added, but the activityrecovered to normal level after 35 days of application. Soil cellulase activity was distinctlyadvanced, subsequently recovered to normal level. Soil phosphatase activity showed higher activityin a short time, but subsequently was inhibited in a long time.The influence of chlorimuron-ethyl on three soil enzymes are as follows: Soil urease activitywas seriously inhibited, cellulase activity was distinctly advanced; phosphatase activity wasdistinctly advanced also in a short time, but rapidly declined significantly.The influence of clomazone on three soil enzymes are as follows: Soil urease activity wasinhibited at first and then advanced. Cellulase activity was advanced significantly in 28 days, andthen gradually recovered. Phosphatase activity was advanced significantly in 21 days, butsubsequently recovered to the normal.4. Initially, There was no degradation effect, the lag phase was 12 hours, henceforthdegradation microorganism IZP-1 began to rapidly degrade imazethapyr, and the degradation ratewas over 90% up to 72 hours. The lag phase was postponed 24 hours, when adding carbonresources such as glucose, lactose, cane sugar, mult sugar and sodium citrate to the culture medium,but the final degradation effect was not influenced. The optimal temperature was 25℃and pHacidity was 5-7 in degradation.There was not obvious lag phrase during the course of degradation microorganism YW-1degrading the herbicide chlorimuron-ethyl, and the degradation speed was stable. To 36 hours, thedegradation ratio was 40%, and the residual ratio was zero to 96 hours. The extra carbon sourcesdidn’t influence on degradation effect. 30℃and pHS-7 is the optical growth condition of YW-1.The compound degradation microorganism CZ-1+CZ-2 could completely degrade clomazone,and there was not obvious lag phrase. In 36 hours, the degradation ratio was 90%, and clomazonewas completely degraded in 48 hours. Adding carbon sources, the lag phrase of degradation was 36hours, and subsequently clomazone was rapidly degraded. The optical degradation condition was25℃-30℃and pH8-9.5. Degradation microorganism IZP-1 could partly bio-remedy the influence of imazethapyr onthe amount, fresh and dry weight of soybean nodule. The lower application dose of imazethapyrwas, the better the in-situ bioremediation effect was received.Degradation microorganism YW-1 could partly bio-remedy the influence of chlorimuron-ethylon the amount, fresh and dry weight of soybean nodule. The compound degradation microorganism CZ-1+CZ-2 could completely bio-remedy theinfluence ofclomazone on the amount, fresh and dry weight of soybean nodule.6. Degradation microorganism IZP-1 could weaken the simulative effect of imazethapyr onfungi, the fungi population obviously decreased initially, and began to increase up to mid-July. Theactinomycetes population increased continually and was higher than the control. IZP-1 could partlybio-remedy the influence of imazethapyr on fungi and actinomycetes population.After applying degradation microorganism YW-1, the fungi population decreased, and higherthan the control. The actinomycetes population increased and accelerated their growth andpropagation. YW-1 could partly bio-remedy the population of fungi and actinomycetes.The compound degradation microorganism CZ-1+CZ-2 could decreased the fungi populationthat increased after applying clomazone, and was higher than the control, namely the in-situbioremediation was not complete. The compound degradation microorganism CZ-1+CZ-2 madeactinomycetes population change more stably and could bio-remedy actinomycetes populationpartly.7. Degradation microorganism IZP-1 could completely bio-remedy the influence ofimazethapyr on soil urease, cellulase and phosphatase activity, and there was no side effect whenimazethapyr didn’t influence on the three enzymes.Degradation microorganism YW-1 could partly bioremedy the effect of chlorimuron-ethyl onsoil urease, cellulase and phosphatase activity, and there was no side effect.The compound degradation microorganism CZ-1+CZ-2 could only partly but not completelybio-remedy the influence of clomazone on soil urease, cellulase and phosphatase activity also.The influence of imazethapyr, chlorimuron-ethyl and clomazone on soil urease, cellulase andphosphatase activity could recover naturally before Mid-July, namely the in-situ bioremediation ofthree long residue herbicides degradation microorganism could react effectively before this time.更多还原