长期施肥对不同作物生产体系土壤团聚体中微生物群落的影响

发布时间：2018-04-23 01:09

本文选题：施肥 + 作物生产体系　；参考：《中国农业大学》2016年博士论文

【摘要】：土壤在全球主要的生物地球化学循环中发挥着关键的作用,并为大量生物提供了居所。团聚体是土壤的基本结构单元,因此是生物地球化学循环过程的重要场所。微生物是土壤生态系统中最活跃的部分,它们的生命活动影响着土壤碳氮循环和土壤团聚结构的形成和稳定性。因此了解团聚体中微生物分布,对于理解这些生物地球化学过程具有重要的意义。本文以华北平原长期定位试验平台,系统分析了不同作物生产体系下,长期施肥对土壤养分、全土微生物群落结构、团聚体碳氮浓度和微生物群落特征等的影响。本研究具体选取以下三组作物轮作体系试验：(1)温室蔬菜种植体系：有机温室和常规温室；(2)小麦-玉米轮作体系：有机肥、常规施肥、不施肥和自然恢复地；(3)不同作物种植模式体系：有机农田(苜蓿-小麦-苜蓿-玉米轮作)、常规农田(冬小麦套种夏玉米)、不施氮农田(小麦-玉米轮作)和自然恢复地。采用湿筛法获得3种粒径的团聚体：0.25 mm(大团聚体)、0.053-0.25mm(微团聚体)和0.053mm(粉粘粒)。同时采用实时荧光定量(qPCR)、末端限制性片段多态性分析(T-RFLP)和克隆文库等分子生物学方法测定土壤微生物群落结构。研究结果表明：温室蔬菜生产体系中,施用有机肥可以改善土壤养分条件和团聚碳氮水平。与常规管理相比,有机管理下的团聚体有机碳和全氮浓度分别提高13-153%和30-146%。在两种管理下,有机碳和全氮浓度都随团聚体粒径的减小而降低,微团聚体组分对全土碳氮含量贡献率分别为42-65%和43-66%。与常规管理相比,有机管理可以提高团聚体中微生物数量,对微生物多样性的影响不显著。冗余分析表明,温室蔬菜生产条件下,微生物的分布受团聚体结构本身的影响。T-RFLP和克隆文库结果表明,细菌群落中变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和拟杆菌门(Bacteroidetes)在各级团聚体中均有发现,酸杆菌门(Acidobacteria)仅在微团聚体和粉粘粒组分中发现。真菌类群在大团聚体组分中较丰富,末端限制性片段257 bp(子囊菌门Ascomycota)及272和294 bp(接合菌门Zygomycota)在三个级别团聚体中均有发现。小麦-玉米轮作生产体系中,长期施有机肥可以改善土壤养分条件,而施用化肥仅提高土壤有效磷的含量。施肥处理(有机肥和化肥)对表层土壤团聚体中有机碳和全氮浓度影响存在差异。与不施肥对照相比,施有机肥处理对各级团聚体中碳氮浓度有显著的提高作用,施化肥处理提高微团聚体组分碳氮浓度而降低大团聚体和粉粘粒组分中碳氮浓度。在所有处理中,有机碳和全氮浓度与团聚体粒径大小成正比。冗余分析结果表明,团聚体重量直径、有机碳和全氮浓度和土壤微生物生物量呈正相关,这说明团聚体结构和碳氮水平影响着微生物的分布。各级别团聚体中微生物数量的分布与有机碳和全氮浓度规律相似,随团聚体粒径减小而降低。在长期施肥条件下,微生物在团聚体的分布存在差异。细菌群落中变形菌门(Proteobacteria)在大团聚体和微团聚体组分中分布较多,而拟杆菌门(Bacteroidetes)在微团聚体和粉粘粒组分中聚集。真菌群落在大团聚体组分与全土的组成相似,而在微团聚体和粉粘粒组分结构相似。在第三组实验中,作物种植模式对团聚体有机碳、全氮浓度和微生物群落结构产生不同影响。与不施氮肥处理相比,有机农田提高了各级团聚体中碳氮浓度,常规农田增加了粉粘粒组分中有机碳浓度和微团聚体与粉粘粒组分中全氮浓度。各处理团聚体中有机碳和全氮浓度随团聚体粒径减小而降低,微团聚体组分对全土有机碳和全氮含量贡献率分别为52-66%和52-69%。与不施氮肥农田相比,有机农田和常规农田均提高了全土细菌的数量和多样性,降低了真菌数量和多样性。冗余分析表明,有机碳和全氮浓度及有效磷含量促进了土壤真菌数量。各级土壤团聚体中的细菌群落在存在差异,其中变形菌门(Proteobacteria)主要在大团聚体中分布,而酸杆菌门(Acidobacteria)在微团聚体组分中较丰富。真菌在团聚体中分布主要受作物种植模式的影响,比如有机农田与常规农田对团聚体中真菌群落结构产生了显著差异。总之,不同作物生产体系中,长期施肥能够提高团聚体中有机碳和全氮浓度,对团聚体微生物群落结构产生影响,但对细菌和真菌的影响规律不同。细菌群落在团聚体中的分布受团聚体物理结构及碳氮水平的影响。真菌群落在团聚体中分布受种植作物种类及施肥的共同影响。
[Abstract]:Soil plays a key role in the world's major biogeochemical cycle and provides a place for a large number of organisms. Aggregates are the basic structural units of the soil, so it is an important place for the biogeochemical cycle. Microbes are the most active part of the soil ecosystem, and their life activities affect soil carbon and nitrogen. The formation and stability of cyclic and soil agglomeration structures. Therefore, to understand the distribution of microbes in the aggregates is of great significance for understanding these biogeochemical processes. In this paper, the soil nutrient and whole soil microbial community structure under different crop production systems were systematically analyzed under the long-term positioning test platform of North China Plain. The effects of carbon and nitrogen concentration and microbial community characteristics of aggregates. The following three crop rotation system experiments were selected: (1) greenhouse vegetable planting system: Organic greenhouse and conventional greenhouse; (2) wheat maize rotation system: organic fertilizer, conventional fertilization, no fertilization and natural recovery; (3) different crop planting pattern system: (3) Organic farmland (alfalfa - wheat - alfalfa - maize rotation), conventional farmland (winter wheat interplanting summer corn), no nitrogen application (wheat - corn rotation) and natural recovery. 3 kinds of aggregate aggregates were obtained by wet screening method: 0.25 mm (large aggregate), 0.053-0.25mm (micro polymer) and 0.053mm (powder clay). Real time fluorescence quantitative (qPCR) was used at the same time. The soil microbial community structure was determined by the end restriction fragment polymorphism analysis (T-RFLP) and clone library. The results showed that the application of organic fertilizer in the greenhouse vegetable production system could improve the soil nutrient conditions and the concentration of carbon and nitrogen. The concentration of organic carbon and total nitrogen in the concentration of 13-153% and 30-146%. decreased with the decrease of aggregate particle size. The contribution rate of micro aggregate to total soil carbon and nitrogen content was 42-65% and 43-66%., respectively, compared with conventional management. Organic management could increase the amount of microorganism in the aggregate, and the effect on microbial diversity was not. In greenhouse vegetable production, the distribution of microbes was affected by the structure of aggregates,.T-RFLP and clone library results showed that Proteobacteria, Actinobacteria and Bacteroidetes were found in all levels of aggregates, and acid bacilli (Acidobacte). RIA) was found only in the micro aggregates and powder clay components. Fungal groups were more abundant in the large aggregate components, the terminal restrictive fragments 257 BP (atlum Ascomycota) and 272 and 294 BP (conjugation fungus Zygomycota) were found in three grade aggregates. In the wheat corn wheel production system, long-term organic fertilizer could improve the soil The effects of fertilizer treatment (organic manure and chemical fertilizer) on the concentration of organic carbon and total nitrogen in the surface soil aggregates were different. Compared with the non fertilization, the application of organic fertilizer treatment could improve the concentration of carbon and nitrogen in the aggregates at all levels, and the fertilizer treatment improved the micro aggregate. The concentration of carbon and nitrogen decreased the concentration of carbon and nitrogen in the large aggregate and the powder clay. In all treatments, the concentration of organic carbon and total nitrogen was proportional to the size of the aggregate. The results of redundant analysis showed that the weight diameter of the aggregate, the concentration of organic carbon and total nitrogen were positively related to the soil microbial biomass, which indicated the structure of the aggregate and the carbon and nitrogen water. The distribution of microbes in all levels of aggregates is similar to that of organic carbon and total nitrogen, and decreases with the decrease of aggregate size. In the long-term fertilization, the distribution of microbes in the aggregate is different. In the bacterial community, the Proteus (Proteobacteria) is in the large aggregate and the microaggregate components. The distribution of Bacteroidetes in the microaggregates and the powder clay fractions. The fungi community is similar to the composition of the whole soil in the large aggregate and the structure of the microaggregates and the powder clay. In the third groups, the crop planting pattern has the organic carbon, the total nitrogen concentration and the microbial community structure in the aggregate. The organic farmland increased the concentration of carbon and nitrogen in the aggregate and the concentration of organic carbon in the powder clay fractions and the concentration of total nitrogen in the microaggregates and the powder clay fractions. The contribution rate of total soil organic carbon and total nitrogen content was 52-66% and 52-69%., respectively, compared with non fertilizer nitrogen fertilizer, organic farmland and conventional farmland both increased the number and diversity of whole soil bacteria and reduced the number and diversity of fungi. The redundancy analysis showed that the organic carbon and total nitrogen and the content of the available phosphorus promoted the soil fungi. There are differences in the bacterial community in the soil aggregates, in which the Proteobacteria is mainly distributed in the large aggregates, and the acid bacilli (Acidobacteria) is more abundant in the micro aggregate components. The distribution of fungi in the aggregate is mainly influenced by the crop planting pattern, such as the organic and conventional farmland for the fungus community in the aggregate. There are significant differences in structure. In a word, long-term fertilization can increase the concentration of organic carbon and total nitrogen in the aggregate, affect the structure of the aggregate microorganism community, but have different influence on the bacteria and fungi. The distribution of the bacterial community in the aggregate is influenced by the physical structure of aggregate and the level of carbon and nitrogen in the aggregate. The distribution of fungal communities in aggregates is influenced by planting crops and fertilization.

【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S154.3

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