生物炭基肥对植烟土壤养分及根际真菌群落结构与功能影响分析

Effects of biochar-based fertilizer on soil nutrients and rhizosphere fungi community structure and function in tobacco planting soil

植烟土壤生物学特性对土壤肥力和土壤养分循环非常重要,是评价土壤肥力的重要生物学指标。探讨减氮条件下配施生物炭基肥对秦岭烟区植烟土壤养分、酶活和真菌群落组成的影响,以期为植烟土壤养分高效利用和根际微生物态菌群结构改善提供理论依据。采用随机区组试验设计,设置两个试验处理:常规施肥(CK),750 kg·hm^(-2)生物炭基肥+常规施肥减氮10%(ST)。在烟苗移栽后75 d采集土壤样品,利用高通量测序技术对植烟根际土壤真菌群落及环境因子进行分析。生物炭基肥能够提高土壤的基础理化性质,增加真菌群落的α多样性,改变真菌群落结构;生物炭基肥能够降低子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、毛霉菌门(Mucoromycota)等优势菌门的相对丰度,增加芽枝菌门(Blastocladiomycota)、镰刀菌属(Fusarium)的相对丰度,同时降低植烟土壤根际病理营养型真菌的相对丰度,在植物生长发育过程中对植物病害有一定的抵御作用。根际土壤真菌群落结构的改变是多因子共同作用的结果,相关性分析表明,门水平下真菌大多与土壤理化性质呈正相关关系。研究结果说明,施用生物炭基肥有利于土壤养分的固持作用,显著改善烟株根际微生物群落结构,增加优势微生物相对丰度,降低病理营养型真菌的相对丰度。

Biological characteristics of tobacco soil are very important for soil fertility and soil nutrient cycling,and are important biological indexes for evaluating soil fertility.In this paper,the effects of combined application of biochar-based fertilizer on nutrient,enzyme activity and fungal community composition of tobacco-planting soil in Qinling tobacco-growing area under nitrogen reduction conditions were investigated,in order to provide theoretical basis for the efficient utilization of soil nutrients and the improvement of rhizosphere microbial flora structure.A randomized block experimental design was adopted,and two experimental treatments were set up:conventional fertilization(CK),and 750 kg·hm^(-2) biochar-based fertilizer+nitrogen reduction by 10%(ST).Soil samples were collected 75 days after tobacco seedling transplantation,and the rhizosphere soil fungal community and environmental factors were analyzed by high-throughput sequencing technology.Biochar based fertilizer improved the basic physical and chemical properties of soil,increased theαdiversity of fungal community,and changed the structure of fungal community.Specifically,biochar-based fertilizers reduced the relative abundance of dominant phyla such as Ascomycota,Basidiomycota and Mucoromycota,and the relative abundance of Blastocladiomycota and Fusarium was increased,while the relative abundance of pathotrophic fungi in rhizosphere of tobacco-growing soil was decreased,which had a certain resistance to plant diseases in the process of plant growth and development.The change of rhizosphere soil fungal community structure was the result of multi-factor interaction.Correlation analysis showed that fungi at phylum level were mostly positively correlated with soil physicochemical properties.The results showed that the application of biochar base fertilizer was beneficial to soil nutrient retention,regulating rhizosphere microbial community structure,increasing the relative abundance of dominant microorganisms,reducing the relative abundance of pathophysiological fungi,and enhancing the resistance of tobacco plants.