Journal of Integrative Agriculture ›› 2021, Vol. 20 ›› Issue (5): 1121-1136.DOI: 10.1016/S2095-3119(20)63341-X

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  • 收稿日期:2020-04-24 出版日期:2021-05-01 发布日期:2021-04-12

Dynamics of microbial diversity during the composting of agricultural straw

CHANG Hui-qing1, ZHU Xiao-hui1, WU Jie1, GUO Da-yong1, ZHANG Lian-he1, FENG Yao   

  1. 1 Henan University of Science and Technology, Luoyang 471023, P.R.China
    2 Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs, Beijing 100081, P.R.China
  • Received:2020-04-24 Online:2021-05-01 Published:2021-04-12
  • Contact: Correspondence FENG Yao, Tel: +86-10-82108657, E-mail: fengyao73@126.com
  • About author:CHANG Hui-qing, Tel: +86-379-62836240, E-mail: hqchang@126.com;
  • Supported by:
    The authors are thankful for foundation support from the National Key R&D Program of China (2017YFD0801304) and the National Natural Science Foundation of China (31972943).

摘要:

本研究采用高通量测序法,对添加添加剂的农作物秸秆好氧堆肥过程(升温、高温、降温和腐熟四个阶段)中微生物多样性动态变化进行研究。此外,还对堆肥过程中理化参数的变化进行分析。添加尿素或尿素与微生物菌剂配合添加,可延长堆体高温发酵时间。C/N比和发芽指数变化表明,添加剂直接改变了堆肥的理化性质,影响了细菌和真菌的多样性和丰富度,有利于堆肥化。在高温阶段,秸秆中添加尿素+微生物制剂处理(SNW),其真菌和细菌丰度(OTU)、多样性指数(Shannon)和丰富度指数(Chao)较单独秸秆处理(S)显著增加。不同堆肥阶段,细菌和真菌门、属两级优势菌的相对丰度存在差异。在高温阶段,厚壁菌门和变形菌门的丰度依次为SNW>SN>S。葡萄球菌属、芽孢杆菌属和热裂菌属在中温阶段的丰度顺序相同。子囊菌占真菌总序列的92%以上。随着堆肥过程的进程,子囊菌的丰度逐渐降低。子囊菌在高温期的丰度顺序为S>SN>SNW。曲霉属的丰度占真菌总丰度的4-59%,并在前两个采样周期内丰度增加。曲霉丰度大小顺序为SNW>SN>S。此外,主成分分析(PCA)表明,稻草和稻草+尿素处理的群落组成相似,中温期(第1天)S、SN和SNW处理的细菌群落与其他3个阶段(分别在第5、11和19天)观察到的细菌群落不同,而真菌群落在堆肥过程只表现出轻微的变化。典型相关分析(CCA)和冗余分析(RDA)表明,总碳(TC)、NO3-N(NN)、电导率(EC)和pH值与群落组成高度相关。因此,本研究表明添加剂有助于农作物秸秆堆肥腐熟,并且有利于堆肥品质的改善


Abstract:

The dynamic changes in microbial diversity during the aerobic composting of agricultural crop straw with additives were evaluated using high-throughput sequencing at four phases of composting (mesophilic, thermophilic, cooling and maturation phases).  In addition, the physicochemical parameters of the composting system were determined in this study.  The fermentation time of the thermophilic period was prolonged with the addition of urea or urea combined with a microbial agent.  The ratio of C/N and germination index variation indicated that the additives were favorable for composting, because the additives directly changed the physicochemical properties of the compost and had effects on the diversity and abundance of bacteria and fungi.  The abundance of operational taxonomic units (OTUs), diversity index (Shannon) and richness index (Chao1) of fungi and bacteria were found to significantly increase when urea+microbial agents  were added to straw in the thermophilic phase.  The relative abundance of the predominant bacteria and fungi at the phylum and genus levels differed during different composting phases.  The abundance of the phyla Firmicutes and Proteobacteria declined in the order of treatments SNW>SN>S (S is straw only compost; SN is straw+5 kg t–1 urea compost; and SNW is straw+5 kg t–1 urea+1 kg t–1 microbial agent compost) in the thermophilic phase.  The abundance of the genera Staphylococcus, Bacillus and Thermobifida followed the same order in the mesophilic phase.  Ascomycota accounted for more than 92% of the total fungal sequences.  With the progression of the composting process, the abundance of Ascomycota decreased gradually.  The abundance of Ascomycota followed the order of S>SN>SNW during the thermophilic phase.  The abundance of Aspergillus accounted for 4–59% of the total abundance of fungi and increased during the first two sampling periods.  Aspergillus abundance followed the order of SNW>SN>S.  Additionally, principal component analysis (PCA) revealed that the community compositions in the straw and straw+urea treatments were similar, and that the bacterial communities in treatments S, SN and SNW in the mesophilic phase (at day 1) were different from those observed in three other phases (at days 5, 11, and 19, respectively), while the fungal communities showed only slight variations in their structure in response to changes in the composting process.  Canonical correlation analysis (CCA) and redundancy analysis (RDA) showed that total carbon (TC), NO3-N (NN), electrical conductivity (EC) and pH were highly correlated with community composition.  Therefore, this study highlights that the additives are beneficial to straw composting and result in good quality compost.
 

Key words: crop straws ,  microbial diversity ,  community composition ,  dynamic characteristics ,  high-throughput sequencing