摘要
摘要:为因地制宜鉴选适宜的秸秆腐熟剂，在西辽河平原灌区选择秸秆还田的砂壤土和中壤土连作玉米地，分别配施中农绿康腐熟剂、人元腐熟剂和农富康腐熟剂（简称中农、人元、农富康），以秸秆还田不施腐熟剂为对照，在玉米吐丝期取0~15 cm、15~30 cm、30~45 cm土层样品，采用高通量测序技术，研究不同质地土壤秸秆还田配施腐熟剂情况下土壤真菌群落结构的多样性。结果表明，砂壤土秸秆还田配施腐熟剂处理特有OTU（operational taxonomic units）数均比对照多，中壤土则相反。所有处理土壤中被孢霉门（Mortierellomycota）、子囊菌门（Ascomycota）、担子菌门（Basidiomycota）相对丰度较高；优势属均为被孢霉属（Mortierella）和低温酵母（Guehomyces）。不同腐熟剂对土壤质地产生不同影响，中壤土秸秆还田配施中农和农富康对土壤真菌组成及丰度无显著影响，而配施人元显著改变中壤土真菌组成及丰度；砂壤土秸秆还田配施中农和人元显著增加土壤真菌组成及丰度。LEfSe分析可知，砂壤土秸秆还田配施中农、中壤土秸秆还田配施人元和农富康3个处理土壤真菌多样性存在差异，对真菌多样性差异发挥显著性作用的门为担子菌门、子囊菌门，纲为伞菌纲（Agaricomycetes），目为腔菌目（Pleosporales）和伞菌目（Agaricales），种为Mortierella fimbricystis。这种响应差异也体现在同一腐熟剂对中壤土和砂壤土不同土层真菌的影响；随土层的下移，砂壤土和中壤土对照中被孢霉属相对丰度先增加后下降，低温酵母相对丰度下降；施用腐熟剂后（中壤土农富康除外），深层土壤低温酵母相对丰度比表层土壤高。砂壤土秸秆还田配施中农后0~15 cm土层中上述2个优势菌属相对丰度显著提高；而中壤土秸秆还田配施人元增加0~15 cm土层低温酵母相对丰度和15~30 cm、30~45 cm土层被孢霉属相对丰度。由此可见，秸秆还田条件下腐熟剂与土壤质地间响应不同，所以秸秆腐熟剂配施应因地制宜。
关键词:中壤土/
砂壤土/
玉米秸秆还田/
秸秆腐熟剂/
真菌多样性
Abstract:In order to select a straw maturing agent suited to local conditions, straw return on medium and sandy loam were investigated in a continuous maize crop in the West Liaohe Plain irrigation area. Straw returned to the field was treated with Zhongnonglvkang, Renyuan, or Nongfukang maturing agent, or without maturing agent as a control. The diversity and community structure of soil fungi was studied using a high-throughput sequencing technique in 0-15 cm, 15-30 cm and 30-45 cm soil layers during the maize silking stage. The results showed that the number of OUT (operational taxonomic units) in sandy loam treated with returned straw and maturing agent was higher than that of control. However, in medium loam, the results were opposite. The relative abundance of Mortierellomycota, Ascomycota, and Basidiomycota for all treatments was higher than in the control, the dominant genera being Mortierella and Guehomyces. Different straw maturing agents and soil textures resulted in different fungi responses. The composition and abundance of soil fungi in medium loam were not significantly affected by returning straw with Zhongnong and Nongfukang application, although applying Renyuan led to significant changes. Significant composition changes and an increase in soil fungi abundance were identified in sandy loam when returned straw was treated with Zhongnong and Renyuan. The results of Linear discriminant analysis Effect Size (LEfSe) analysis showed that soil fungi diversity differed among three treatments. For sandy loam with Zhongnong application, medium loam with Renyuan, and medium loam with Nongfukang, the most significant fungal classifications were phyla Basidiomycota and Ascomycota, class Agaricomycetes, orders Pleosporales and Agaricales, and species Mortierella fimbricystis. The difference in treatment response was also reflected in the maturing agent effects on fungi in different layers of medium and sandy loam. With increased depths, the relative abundance of Mortierella spp. first increased and then decreased, while the relative abundance of Guehomyces spp. decreased. The relative abundance of Guehomyces spp. in deep soil was higher than that in surface soil after the application of straw maturing agent (except for Nongfukang in medium loam). The relative abundance of these two dominant genera in the 0-15 cm soil layer was significantly increased in sandy loam by returning straw and applying Zhongnong. In medium loam, returning straw and applying Renyuan increased the relative abundance of Guehomyces spp. in the 0-15 cm soil layer and the relative abundance of Mortierella spp. in the 15-45 cm soil layer. Under returned straw conditions, effects of straw maturing agent varied with soil texture; therefore, the combined application of straw and straw decomposing agents should be adapted according to local conditions.
Key words:Medium loam/
Sandy loam/
Maize straw returning to field/
Straw maturing agent/
Fungal diversity



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