【作者】 孙佳杰；

【导师】 尹建道；

【作者基本信息】 天津理工大学 ， 环境科学， 2010， 硕士

【摘要】 土地盐碱化是土地退化的一种重要表现形式,是当今世界主要的资源环境问题之一,天津及环渤海地区尤其突出。本研究以盐碱地改良和开发利用为目标,以天津滨海地区不同盐化程度的表层土壤(0~20cm)为对象,测定分析了土壤理化性质和微生物类群的数量特征,探讨盐渍环境与微生物类群之间的生态关系,并初步鉴定了盐碱土壤中的微生物优势菌属,同时对引进的微生物菌肥分别进行了盆栽试验和大田试验,获得了大量的第一手资料。主要研究结论如下:(1)试验区内的土壤盐碱程度明显呈斑块状分布,土壤含盐量变动在0.5‰~18.5‰之间,大小相差37倍;土壤pH值变动在7.64~8.82之间,普遍呈碱性;土壤有机质含量低(<10g/kg),肥力状况差。根据同一土壤样品的含盐量和电导率之间具有正相关关系,通过大量样品建立了两者之间的线性回归关系,其关系式为y=0.0033x-0.6736,达到了极显著水平;实测检验结果表明,公式求算值与重量法的平均误差为3.88%,完全可以满足生产实践的精度要求,该关系式的建立将大大减少土壤含盐量测定的工作量,简便易行。(2)土壤微生物总量变动在0.75×10~5~14.19×10~5cfu/g之间,相差19倍,与其它地区或其它类型的土壤相比,微生物总量较少;土壤中细菌占绝对优势,放线菌次之,真菌最少,且随着土壤含盐量的增加,细菌所占比例逐渐增大,但真菌变幅较小。随着土壤盐化程度的增加,其中的微生物数量在不断减少,呈明显的负相关,其关系式为y=-3.7598lnx+11.281,R~2=0.8787。土壤微生物中细菌、放线菌、真菌三大类群的数量从大到小依次为轻度盐化土、中度盐化土、重度盐化土、盐土,充分反映了以盐害为主导因子的土壤环境条件的综合影响。(3)土壤微生物经分离、纯化、鉴定,细菌共分离出8个菌属,以乳杆菌属、芽孢杆菌属为主,同时也分离鉴定出了盐杆菌属、不动杆菌属、微杆菌属等耐盐菌属;放线菌分离鉴定出3个菌属,以链霉菌属为优势菌群;真菌数量较少,以青霉属为主。菌属的初步分离和鉴定,尤其是耐盐菌属的分离和发现为盐碱土壤专用微生物肥料的研发提供难得的理论依据。(4)施用微生物肥料可以明显降低盐渍土壤的含盐量、增加有机质含量以及土壤中微生物类群的数量,对于改良土壤物理、化学和生物性质起到良好作用。同时,在使用不同种类和浓度的微生物肥料后,植物的生长状况均得到了改善,生长效果均好于空白对照组,且浓度与效应关系显著。(5)通过盆栽和大田试验的综合评价结果表明:适宜天津滨海地区使用的肥料为有机肥+益生菌发酵,最佳的使用量为9kg/m~2。增施肥料后可以明显促进羊草的长势,改善盐渍土的理化环境,建议在今后的生产实践中大力推广应用,以促进天津滨海地区园林绿化事业的健康发展。更多还原

【Abstract】 Soil salination was a significant form of land degradation, which was one of the world’s major resource and environmental problems. The aim of this research was to improve and develop the saline-alkali soil. The study took the saline-alkali soil of Tianjin coastal area as the object and analyzed the physical and chemical properties as well as the number of microorganism which had identified dominant species. The foreign microbial fertilizer was experimented with potted plants and field respectively, from which abtained a vast number of first-hand information. The experiments showed the following conclusions:(1) The salination degree of experiented soil was distributed with speckle, the salinity content changed between 0.5‰~18.5‰, 37 times between the lowest and the highest; the pH was in the range of 7.64～8.82, which presented the basic; the organic content was low and with the fertility was in poor condition. There was positive correlation between salt content and conductivity of the same soil sample, by a large number of samples established linear relationship between the two index, the regression equation was y=0.0033x-0.6736, the correlation was good,the establishment of the relationship could reduce the workload of drying method.(2) The quantity of microbe in the soil changed in the range of 0.75×10~5~14.19×10~5 cfu/g, the number was less compared with soil in other areas or other types. Bacilli were absolutely dominated, and then the actinomycetes, the fungi were least. The higher salinity in soil, the less microorganism quantity, its relation equation was y =-3.7598lnx+11.281.The amount of microbe from more to less were Light degree, Middle degree, High degree and Salt soil, it has fully reflected the soil environmental condition synthesis influence as the leading factor of soil harm.(3) With isolated and identified, there was eight species of the bacilli, the primary were Lactobacillus and Bacillus, and Halobacterium, Acinetobacter, Microbacterium etc. of salt-tolerant microbe were identified at the same time. The primary of actinomycetes were Streptomycete, and the most of fungus were Penicillium. The discovery of Halotolerant Domesticated has the important theory and the practical significance to study the saline-alkali soil in our country’s coastal region and to develop saline-alkali soil special-purpose fertilizer.(4) Application of microbial fertilizer could significantly reduce the salinity of saline soil and increase soil organic content. While different kinds and densities of fertilizer application the number of microorganism in the soil significantly increased, and it had played better effect on soil, and it had better affect upon soil improvement properties.(5) Through potted and field experiments showed that the most suitable fertilizers in Tianjin Coastal area was organic manure + EM, the best amount of usage was 9kg/m~2. After manured it could significantly improve the growth feature of the plants, and improve the physical and chemical environment of the saline-alkali soil. In order to promote the green engeering in Tianjin coastal region this organic manure + EM could be considered using in green production.更多还原