黑土长期定位试验原状土搬迁对土壤微生物的影响

发布时间：2018-08-07 15:01

【摘要】：东北黑土土质肥沃、质地疏松、有机质丰富,但近年来肥力呈下降趋势。长期定位试验在研究土壤肥力、环境演变和作物产量等方面具有重要意义,深受国内外重视。我国从80年代初开始建立土壤肥料长期定位试验,但是由于城市化进程加快,使一些长期定位试验面临被毁或搬迁的局面。土壤微生物对其生存的微环境十分敏感,可受到耕作方式、植被类型和土壤肥力等多方面因素的影响。本研究通过测定黑土长期定位试验原状土整体搬迁前后四种处理(CK、NPK、M、MNPK)两个土层(0~20 cm、20~40 cm)中土壤微生物量含量、土壤酶活性以及土壤微生物群落结构的变化,探讨搬迁的特定条件对土壤微生物性质的影响。主要研究结果如下:(1)比较搬迁前后5年间三大类微生物数量、微生物量碳、氮含量和4种土壤酶活性的变化发现,各项生物指标年际间虽存在变化但变化程度并不大,其中搬迁后2011年和2012年相对较高,同为小麦茬的搬迁前2010年和搬迁后2013年各项生物指标均较为接近;(2)细菌DGGE图谱中搬迁前后两个土层不同处理所有样品之间具有相似性,而真菌DGGE条带的数量和亮度在搬迁前后两个土层不同处理样品之间存在部分变化;(3)对DGGE图谱进行聚类分析可知,细菌群落结构在两个土层各处理中搬迁前后变化不大,而真菌有部分变化,其中真菌搬迁前后MNPK处理的变化较为显著;(4)对DGGE图谱进行主成分分析可知,在0~20 cm土层细菌和真菌各处理虽然搬迁前和搬迁后产生分异,但在2年中处理间的分布规律相一致,在20~40 cm土层中搬迁前和搬迁后细菌的MNPK和NPK处理分布规律发生了变化,真菌MNPK和CK处理发生了变化。(5)DGGE条带测序结果显示,变形杆菌门(Proteobacteria(δ-andγ-))和放线菌门(Actinobacteria)是农田黑土中细菌的优势类群,并且稳定的存在于农田黑土中;担子菌门(Ascomycota)和子囊菌门(Basidiomycota)是农田黑土中真菌优势类群,也稳定的存在于农田黑土中。综合以上结果表明,搬迁对土壤微生物的扰动影响远小于耕作方式、植被类型、土壤肥力等的影响。
[Abstract]:The northeastern black soil is fertile, loose and rich in organic matter, but the fertility is declining in recent years. The long-term location test is of great importance to the study of soil fertility, environmental evolution and crop yield. The soil microorganism is sensitive to the microenvironment of its survival, and can be affected by many factors such as farming methods, vegetation types and soil fertility. Four treatments (CK, NPK, M, MNPK) before and after the long term localization test of black soil are measured. The soil microbial biomass content, soil enzyme activity and soil microbial community structure in 0~20 cm (20~40 cm) were studied. The main research results were as follows: (1) compare the number of three kinds of microbes, microbial biomass carbon, nitrogen content and 4 kinds of soil enzyme activity before and after the relocation. It was found that every biological index changed but changed little in year, which was relatively high in 2011 and 2012 after the relocation, and the biological indexes were close to 2010 before and after the relocation of the wheat stubble. (2) the two soil layers in the DGGE map were similar to all the samples before and after the removal of the bacteria. The number and brightness of the DGGE band of fungi had some changes between the two soil layers before and after the relocation. (3) the cluster analysis of the DGGE map showed that the bacterial community structure had little change before and after the removal of the two soil layers, and some of the fungi changed, and the changes of MNPK treatment before and after the removal of fungi were more obvious. (4) (4) the principal component analysis of the DGGE map shows that in the 0~20 cm soil layer, the bacterial and fungal treatments are different before and after the relocation, but the distribution rules of the treatment are consistent in 2 years. The distribution rules of MNPK and NPK treatment of bacteria before and after the relocation of the 20~40 cm soil layer have changed, and the fungal MNPK and CK treatment occurred. (5) the DGGE strip sequencing results showed that the Bacillus proteus (Proteobacteria (delta -and gamma)) and actinomycetes (Actinobacteria) were the dominant groups of bacteria in the black soil of farmland, and were stable in the black soil of the farmland. The basidiomycetes (Ascomycota) and the actinomycetes (Basidiomycota) were the dominant groups of fungi in the black soil of the farmland. The above results show that the disturbance of soil microorganisms by relocation is much less than that by tillage, vegetation type and soil fertility.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S154.3

【参考文献】