长期地膜覆盖与施肥对棕壤微生物群落的影响

发布时间：2018-03-07 04:05

  本文选题：长期施肥　切入点：地膜覆盖　出处：《沈阳农业大学》2016年博士论文　论文类型：学位论文

【摘要】：长期施肥和地膜覆盖影响土壤理化性质,进而影响土壤微生物群落结构和多样性,而微生物多样性对于维持土壤生态系统功能至关重要。关于施肥对土壤微生物多样性影响的研究已有不少,然而这些研究大多采用PCR-DEEG或磷脂脂肪酸(PLFA)等方法,不能从基因水平揭示土壤微生物的多样性,高通量测序的出现成功弥补了这一缺陷。同时,土壤微生物群落中的氨氧化细菌和古菌因其在氮循环过程中的重要作用受到了广泛关注。因此,本文选择沈阳农业大学后山长期施肥定位试验田为研究对象,采用高通量测序手段研究了长期施用化肥、有机肥以及和地膜覆盖相结合等农田措施对土壤微生物多样性和群落结构的影响；同时研究了氨氧化细菌和氨氧化古菌对施肥和地膜覆盖的响应,主要发现如下：(1)高通量测序结果显示研究土壤中的主要细菌门类有：蛋白菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)和硬壁菌门(Firmicutes)。研究发现长期施用化肥结合有机肥显著的降低了土壤微生物的多样性,而单独施用有机肥则提高了土壤微生物的多样性,这与化肥显著降低土壤pH值密切相关。研究发现地膜覆盖对土壤微生物群落结构有显著影响,这种影响主要是通过对土壤有机碳、总氮、有效磷、pH以及土壤水分的间接作用实现的。(2)与不施肥处理相比,长期施用化肥或有机肥显著降低了氨氧化细菌和氨氧化古菌的相对丰度；长期施用有机肥土壤中氨氧化细菌和氨氧化古菌的相对丰度显著高于施用化肥的土壤。总体上讲,地膜覆盖后氨氧化细菌和古菌的相对丰度均显著降低。(3)总体上讲,六月和七月土壤样品中的微生物多样性显著高于十月,同时氨氧化细菌和古菌的丰度也呈现相同的规律,这与温度和水分有较大的关系。相对于六月,七月和十月份长期施用化肥显著降低了土壤微生物的丰度和多样性；在七月,长期施用化肥显著降低了氨氧化细菌的相对丰度,然而在十月,长期施用化肥显著提高了氨氧化细菌的相对丰度。可见,土壤微生物群落多样性以及氨氧化细菌和古菌的相对丰度对施肥和地膜覆盖的响应因取样时间的不同而不同,因此,未来研究应在年内和年间进行多次取样以作出综合评价。
[Abstract]:Long-term fertilization and film mulching affect the physical and chemical properties of soil, and then affect the structure and diversity of soil microbial community. But microbial diversity is very important to maintain the function of soil ecosystem. There have been many studies on the effects of fertilization on soil microbial diversity. However, most of these studies are carried out by PCR-DEEG or phospholipid fatty acid (PLFA). The diversity of soil microbes could not be revealed at the gene level, and the emergence of high-throughput sequencing made up for this defect. Ammonia-oxidizing bacteria and archaea in soil microbial community have been paid more and more attention for their important role in nitrogen cycling. Therefore, the long-term fertilization experiment field of Houshan, Shenyang Agricultural University, was chosen as the research object in this paper. The effects of long-term application of chemical fertilizer, organic fertilizer and mulching on soil microbial diversity and community structure were studied by high-throughput sequencing. At the same time, the responses of ammonia-oxidizing bacteria and ancient ammonia-oxidizing bacteria to fertilization and mulching were studied. The main results of high-throughput sequencing showed that the main bacteria in the soil studied were Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetesand Firutmicesus. Fertilizer significantly reduced soil microbial diversity, Application of organic fertilizer alone increased the diversity of soil microbes, which was closely related to the significant reduction of soil pH value by chemical fertilizers. The results showed that mulch mulching had a significant effect on the structure of soil microbial communities. This effect was mainly achieved by indirect effects on soil organic carbon, total nitrogen, available phosphorus pH and soil moisture. Long-term application of chemical fertilizer or organic fertilizer significantly reduced the relative abundance of ammonia-oxidizing bacteria and ammonia-oxidizing ancient bacteria, and the relative abundance of ammonia-oxidizing bacteria and ammonia-oxidizing ancient bacteria in long-term application of organic fertilizer was significantly higher than that of the soil applying chemical fertilizer. The relative abundance of ammonia-oxidizing bacteria and archaea decreased significantly after mulching film.) on the whole, the microbial diversity in soil samples on June and July was significantly higher than that in October, and the abundance of ammonia-oxidizing bacteria and archaea was the same. Compared with June, July and October, long-term application of chemical fertilizer significantly reduced the abundance and diversity of microbes in soil, and in October, long-term application of chemical fertilizer significantly reduced the relative abundance of ammonia-oxidizing bacteria. In October, however, long-term application of chemical fertilizers significantly increased the relative abundance of ammonia-oxidizing bacteria. The diversity of soil microbial communities and the relative abundance of ammonia-oxidizing bacteria and palaeomycetes are different in response to fertilization and mulching with different sampling times. Therefore, a number of samples should be taken for comprehensive evaluation during the year and each year in the future.
【学位授予单位】：沈阳农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S154.3
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本文编号：1577837