微生物菌剂对碱性土壤氨挥发的控制及其机理研究

发布时间：2018-03-20 22:27

本文选题：微生物菌剂　切入点：氨挥发　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

【摘要】：微生物菌剂是种绿色环保的新型肥料,现在已经作为植物促生剂和生防剂投入实际生产应用中。植物生长促进根际细菌(Plant growth promoting rhizobacteria)和植物生长促进真菌(Plant growth promoting fungi)是土壤中的两类重要微生物菌群,也是常被用来制备微生物菌剂的微生物材料。本研究以氨挥发较为严重的中国北方碱性土壤(pH 8.37-8.43)为研究对象,研究并对比三种不同微生物菌剂和传统化肥的配施对碱性土壤氨挥发减排效果的差异,并从土壤pH、植物生长状况和土壤硝化作用三个角度分析微生物菌剂的控氨机理。本实验中施用两类微生物肥分别为,真菌类微生物菌剂绿色木霉菌(Trichoderma viride),细菌类微生物菌剂解淀粉芽孢杆菌(Bacillus amyloliquefaciens)和多粘类芽孢杆菌(Bacilluspolymyxa),通过对比两类微生物菌剂控氨效果的差异,研究微生物菌剂类型对土壤氨挥发的影响。除此之外,实验利用定量PCR技术和高通量测序技术分析微生物菌剂的施用对土壤微生物数量和种群结构的影响。研究得到以下结论:(1)微生物菌剂对碱性土壤氨挥发的影响不论是施用微生物菌剂还是传统化肥,其土壤氨挥发变化规律类似。它们均在施肥后的几天内出现氨挥发,随着时间的推移,氨挥发速率逐渐升高至峰值,随后氨挥发速率开始下降,直至稳定。在整个试验期间,所有微生物菌剂处理均能在一定程度上减少土壤氨挥发,其中真菌类微生物菌剂绿色木霉菌的控氨效果最佳,氨挥发量相比尿素(CK)处理降低42.21%;微生物菌剂解淀粉芽孢杆菌和多粘类芽孢杆菌的控氨效果较弱,氨挥发量分别降低20.28%和13.81%。(2)微生物菌剂降低土壤氨挥发的作用机理探讨土壤pH、植物对氮素的吸收利用、土壤硝化作用等都是影响土壤氨挥发的关键因素。本研究从这三个角度,详细分析了微生物菌剂降低土壤氨排放的可能机制。首先,pH是影响土壤氨挥发速率的关键因素之一,其值越高,氨挥发速度越快,微生物菌剂的施用降低氨挥发速率峰值期间的土壤pH值;其次,微生物菌剂能够促进高粱的生长,这既提高了作物生物量,减少了土壤氨排放;最后,微生物菌剂能够通过提高硝化菌群的丰度增强土壤硝化作用,促进NH4+-N转化生成N03-N形式,减少氮素损失。(3)微生物菌剂对土壤微生物丰度和群落结构的影响施用微生物菌剂后,所有处理组的土壤微生物群落丰度和结构组成都发生明显改变。其中,真菌类微生物菌剂绿色木霉菌的施用不但提高了土壤微生物群落丰度,同时也增加了微生物群落多样性;细菌类微生物菌剂解淀粉芽孢杆菌和多粘类芽孢杆菌的施用虽然也提高了土壤微生物丰度,但是其微生物组成多样性降低。这说明施用不同类型的微生物菌剂对土壤微生物群落结构产生的影响也会有所不同。
[Abstract]:Microbial agents are a new type of fertilizer that is green and environmentally friendly. Plant growth promoting rhizobacteriae and Plant growth promoting fungida are two important microbial groups in soil. In this study, pH 8.37-8.43 of alkaline soil in northern China, where ammonia volatilization is more serious, was used as the research object. To study and compare the effect of three different microbial agents and traditional chemical fertilizer on ammonia volatilization emission reduction in alkaline soil. The ammonia control mechanism of microbial agents was analyzed from three aspects of soil pH, plant growth and soil nitrification. Trichoderma viridea, Bacillus amyloliquefaciens (Bacillus amyloliquefaciensus), Trichoderma viridea (Trichoderma viridea), Bacillus polymyxaanus (Bacillus polymyxaanus) and Bacillus polymyxaan (Bacillus polymyxaanus) were compared. To study the effect of microbial agent types on soil ammonia volatilization. Quantitative PCR technique and high throughput sequencing technique were used to analyze the effect of microbial agents on soil microbial quantity and population structure. The following conclusion is drawn: 1) the effect of microbial agent on ammonia volatilization in alkaline soil is not obvious. On the use of microbial agents or traditional chemical fertilizers, The changes of ammonia volatilization in soil were similar. Ammonia volatilization occurred in the first few days after fertilization. With the passage of time, the ammonia volatilization rate gradually increased to the peak, and then the ammonia volatilization rate began to decrease until it was stable. All microbial agents could reduce ammonia volatilization in soil to some extent, and the best ammonia control effect was obtained by Trichoderma viride, a fungus microorganism agent. Ammonia volatilization was 42.21 lower than urea CK) treatment, and the ammonia control effect of Bacillus amylolyticus and Bacillus polymyxides was weak. Reduction of ammonia volatilization by 20.28% and 13.81.The mechanism of ammonia volatilization in soil by microbial bacteria was discussed. Soil pH, nitrogen uptake and utilization by plants and soil nitrification were all the key factors affecting ammonia volatilization in soil. The possible mechanism of reducing soil ammonia emission by microbial bacteria was analyzed in detail. First of all, pH was one of the key factors affecting soil ammonia volatilization rate. The higher the soil ammonia volatilization rate, the faster the ammonia volatilization rate. The application of microbial bacteria can reduce the soil pH during the peak ammonia volatilization rate. Secondly, microbial bacteria can promote the growth of sorghum, which not only increases crop biomass, but also reduces soil ammonia emission. Microbial agents could enhance soil nitrification by increasing the abundance of nitrifying bacteria, promote the transformation of NH4 -N to form N03-N, and reduce the nitrogen loss. 3) the effect of microbial agents on soil microbial abundance and community structure was studied. The abundance and structure of soil microbial community in all treatment groups were obviously changed. The application of fungus microorganism agent Trichoderma viride not only increased the abundance of soil microbial community, but also increased the diversity of microbial community. The application of bacterial microorganism agents, Bacillus amylolyticus and Bacillus polymyxis, also increased the soil microbial abundance. However, the diversity of microorganism composition was decreased, which indicated that the effect of different microbial agents on the soil microbial community structure would be different.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S144

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