秸秆沟埋还田对稻田产甲烷菌群落结构的影响
时间:2019-05-10 12:57 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：秸秆沟埋还田是一种新型土壤耕作方式，能够改变土壤理化性质，增加土壤有机质等。通过研究不同还田条件下的稻田产甲烷菌群落结构特征，以期阐明秸秆沟埋还田对稻田甲烷排放的调控机制。分别设置3个单因子实验，包括沟埋深度 (CK、20 cm、30 cm、40 cm)、沟埋量 (CK、半量、全量、倍量) 以及还田方式 (CK、粉碎旋耕、机械沟埋、人工沟埋)。使用Miseq高通量测序平台，解析产甲烷菌群落结构。研究发现，秸秆沟埋还田改变了稻田产甲烷菌群落的物种组成和多样性。在不同沟埋深度下，埋深30 cm的多样性指数和优势种数量低于其他处理；在不同的沟埋量下，全量还田的多样性指数高于其他处理；在不同的还田方式下，机械沟埋的优势种数量要低于其他处理。综上可知，秸秆沟埋还田能够改变稻田产甲烷菌的群落组成，并增加其多样性。35248 毕业论文关键词：稻田；秸秆沟埋还田；产甲烷菌；群落结构；多样性 Effects of ditch-buried straw return on community structure of methanogens in a paddy field Abstract：Ditch-buried straw return is a new type of soil tillage practice, which can change the soil physical and chemical properties, as well as increase soil organic matter and so on. The community structure of methanogens were investigated under different straw incorporation conditions in order to clarify the underlining mechanisms of ditch-buried straw return on methane emission in the paddy fields. Three single factor experiments were set up, including ditch-buried depths (CK, 20 cm, 30 cm, 40 cm), ditch-buried amounts (CK, half, full, multiple) and straw incorporation methods (CK, crushed rotary tillage, mechanical ditch buried, artificial furrow). A Miseq high-throughput sequencing platform was used to analyze the methanogens community structure. Our results showed that the ditch-buried straw return changed the species composition and persity of methanogens in the paddy field. Under different ditch-buried depths, the persity index and the number of dominant species with depth of 30 cm were lower than other treatments. Under the different ditch-buried amounts, the persity index of the full amount treatment is higher than that of other treatments. Under different straw incorporation methods, the number of dominant species in the mechanical ditch is lower than that of other treatments. In summary, the ditch-buried straw return has the potential to change the composition of the methanogens in paddy fields, and increasing its persity. Key words: Paddy field; Ditch-buried straw return; Methanogenic bacteria; Community structure; Diversity 目 录 摘要1 关键词1 Abstract1 Key words1 引言 1 1材料与方法2 1.1试验地概况 2 1.2试验设计 2 1.3研究方法 3 1.3.1取样方法3 1.3.2测定方法3 1.3.3数据分析3 2结果与分析3 2.1不同的沟埋深度3 2.1.1群落组成分析3 2.1.2香农多样性指数4 2.1.3优势种多度分析4 2.2不同的沟埋量5 2.2.1群落组成分析5 2.2.2香农多样性指数5 2.2.3优势种多度分析5 2.3不同的还田方式7 2.3.1群落组成分析7 2.3.2香农多样性指数7 2.3.3优势种多度分析7 3讨论 8 3.1沟埋深度对稻田产甲烷菌群落结构的影响8 3.2沟埋量对稻田产甲烷菌群落结构的影响9 3.3还田方式对稻田产甲烷菌群落结构的影响9 3.4总结10 4结论 10 致谢10 参考文献10 秸秆沟埋还田对稻田产甲烷菌群落结构的影响 全球气候变暖已成为受到国际社会共同关注的重要问题。最主要的温室气体是二氧化碳 (CO2)、氧化亚氮 (N2O) 以及甲烷 (CH4)。它们的大量排放，使大气中温室气体的浓度不断升高，这不仅加剧了全球气候变暖问题，更在不停地威胁着人类赖以生存的环境基础，近几年，随着工业的不断发展，温室气体排放量进一步提高，其中甲烷对全球变暖的贡献率达到15%，仅次于二氧化碳，位居第二，同时甲烷的温室效应要比二氧化碳大上25倍左右，对全球气候变化产生重要影响[1]。 (责任编辑：qin) |