寒地玉米秸秆不同腐熟时期的理化性状及微生物多样性分析

Analysis of Physical and Chemical Characteristics and Microbial Diversity of Corn Straw in Different Maturity Period in Cold Area

为了进一步揭示寒地玉米秸秆在施用低温降解秸秆菌剂下腐熟的过程及机理,为寒地秸秆的腐熟和综合利用工作提供新的策略和参考理论依据,采用低温降解秸秆菌剂在寒地条件对玉米秸秆进行腐熟并对其理化性状及微生物多样性进行分析。根据发酵过程中温度的变化,将玉米秸秆腐熟过程分为5个时期:初始期(A1)、升温期(A2)、腐熟期(A3)、平稳期(A4)及降温期(A5)。不同腐熟时期玉米秸秆的理化性质监测结果如下:随着腐熟时间的延长,玉米秸秆表皮上的纤维束逐渐被破坏;在腐熟结束后,玉米秸秆中纤维素的相对含量降至33.48%,半纤维素的相对含量降至16.57%;秸秆中全氮、铵态氮的含量呈先降低后升高的趋势,有机质的含量降至149.7 g/kg。发酵垛中微生物多样性的监测结果如下:耐冷酵母属在腐熟过程中的丰富度最高,占重要的主导地位;假单孢菌属和鞘氨醇杆菌属在腐熟初始期和腐熟期为主要菌属;在腐熟过程的平稳期和降温期中,嗜热微生物发挥着主要作用。该研究明确了寒地条件下玉米秸秆在施用低温降解秸秆菌剂后腐熟过程中理化性状及发酵垛中微生物多样性的改变。

In order to further reveal the decomposition process and mechanism of corn straw in the cold area under the application of low temperature straw degrading agent,and provide a new strategy and theoretical basis for the decomposition and comprehensive utilization of straw in the cold area.Corn straw was decomposed by low temperature straw degrading agent and its physical and chemical characters and microbial diversity were analyzed.According to the change of temperature in the fermentation process,the ripening process of corn straw was divided into five stages:initial stage(A1),heating stage(A2),ripening stage(A3),stable stage(A4)and cooling stage(A5).The monitoring results of the physical and chemical properties of corn straw in different maturity stages were as follows:with the extension of maturity time,the fiber bundles on the surface of corn straw were destroyed gradually.After maturity during the cooling stage,the relative content of cellulose and hemicellulose in corn straw decreased to 33.48%and 16.57%,respectively,while the content of total nitrogen and ammonium nitrogen in corn straw decreased at first and then increased,and the contents of organic matter decreased to 149.7 g/kg.The monitoring results of microbial diversity in the fermentation stacks were as follows:Guehomces were the most abundant and dominant species in the ripening process;Pseudomonas and Sphingobacterium were the main genera in the initial and ripening stages,and thermophilic microorganisms played a major role in the heating,stationary and cooling stages of ripening.The changes of physical and chemical properties and microbial diversity in fermentation stack of corn straw after the application of low temperature straw degradation agent in cold area were clarified.