微生物菌肥改良渭北地区盐碱化土壤作用及效果研究

发布时间：2018-03-07 03:27

本文选题：盐碱地　切入点：微生物菌肥　出处：《西北大学》2015年硕士论文　论文类型：学位论文

【摘要】：土壤是农林业发展的最基本生产资料,土壤质地优劣与农林业健康发展有着紧密联系。影响土壤质地原因之一是土壤出现盐碱化,盐碱化是指土壤中富含大量盐分。土壤集聚大量盐分会破坏土壤水盐运动平衡、改变土壤结构,致使土壤容重增加,土壤颗粒间隙变小,土壤通透性减弱,土壤渗透率变大,导致土壤板结、胶黏,土壤肥力下降,土壤中的植物生长受阻,危害农林业发展,影响着生态平衡。盐碱化土壤也是一类重要的土地资源,如何解决盐碱化问题是一项科技难题,各国科学家们都在致力研究有效治理盐碱化土壤办法。本研究通过采用微生物菌肥修复技术对盐碱土进行改良,首先从盐碱土壤中分离耐盐微生物菌株,通过富集培养和耐盐筛选得到了能够在含盐量为20g/L的培养基中生长的菌株4株,分别为：NY5、NY16、NY35、NY41.通过对这4株菌进行形态学、生理生化鉴定以及16S rDNA或ITS系列分析,对比NCBI系列,确定了这4株菌分别为：巨大芽孢杆菌属(Bacillus megaterium) NY5、枯草芽孢杆菌属(Bacillus subtilist)NY16、假单胞菌属(Pseudomona sp.)NY35、酵母菌属(Saccharomyces)NY41,采用He-Ne激光诱变技术对这4种菌诱变育种,获得遗传稳定性好,耐盐性强的突变菌株NY5-HN、 NY16-HN、NY35-HN、NY41-HN。将突变株与乳酸杆菌LAB按照不同比例复配发酵微生物菌肥,确定混合菌剂最佳比例：2：2：1：1：1,以最佳比例发酵微生物菌肥,通过单因素试验和正交分析,得出菌肥发酵最优工艺条件：培养物料含水率50%,混合菌剂接入量2%,翻堆通氧3天/次,发酵时间20天。将该试验菌肥应用于大田试验,探究菌肥对盐碱地改良效果和土壤理化性质的影响,还有其对玉米和紫花苜蓿发育的影响。试验结果显示,经过施用微生物菌肥后,试验组土壤各项理化性质均有不同程度的良性变化,种植玉米和紫花苜蓿在萌发率、株高和总产量照对照组提高24%、29.9%；23.1%、33%；40.6%、60.2%。说明微生物菌肥对盐碱地有明显改良修复效果。
[Abstract]:Soil is the most basic means of production for the development of agriculture and forestry. The quality of soil is closely related to the healthy development of agriculture and forestry. Salinization refers to the accumulation of a large amount of salt in the soil, which destroys the balance of soil water and salt movement, changes the soil structure, increases the bulk density of the soil, reduces the gap between soil particles, weakens the permeability of the soil, and increases the permeability of the soil. As a result of soil agglutination, soil fertility decline, plant growth in soil is blocked, agricultural and forestry development is jeopardized and ecological balance is affected. Salinized soil is also an important kind of land resource. How to solve the problem of salinization is a scientific and technological problem, and scientists all over the world are working on the effective treatment of salinized soil. First of all, salt tolerant microorganism strains were isolated from saline-alkali soil. Through enrichment culture and salt tolerance screening, four strains which could grow in the medium containing 20 g / L salt were obtained, which were respectively: 1. NY5NY 16NY35NNY41.Through the morphology of these four strains, Physiological and biochemical identification, 16s rDNA or ITS series analysis, comparison of NCBI series, The four strains were identified as Bacillus megaterium NY5, Bacillus subtilistNY16, Pseudomonas sp. NY35 and Saccharomyces sp. NY41, respectively. The four strains were induced by He-Ne laser mutagenesis to obtain good genetic stability. The mutant strains NY5-HN, NY16-HNN, NY35-HNN, NY41-HN.The optimum proportion of mixed bacteria was determined to be 2: 2: 1: 1: 1: 1 by mixing the mutant strain with Lactobacillus LAB in different proportion, and the optimum proportion of fermentation microbial fertilizer was obtained by single factor experiment and orthogonal analysis. The optimum technological conditions of fermentation were obtained as follows: moisture content of culture material 50%, mixed fungicides 2%, oxygen transfer 3 days / time, fermentation time 20 days. The experiment was applied to the field experiment. The effects of microbial fertilizer on soil improvement and soil physical and chemical properties, as well as on the development of maize and alfalfa were investigated. The soil physicochemical properties of the test group were changed in varying degrees. The germination rate, plant height and total yield of maize and alfalfa in the control group were increased by 240.29. 9% and 23. 1% and 20. 6% and 60. 2% respectively. The results showed that microbial microbial fertilizer had obvious effect on improving and repairing saline soil.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S144;S156.4

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