改良剂调控盐碱胁迫对棉田土壤微生物多样性的影响

Effects of modifier on soil microbial diversity in cotton field under saline-alkali stress

以有机高分子复配材料和黄腐酸为主的复合材料作为盐碱土改良剂,利用田间桶栽控制试验,探究两种改良剂对重度盐碱胁迫下(NaCl、Na_(2)CO_(3))棉田土壤理化性质及细菌群落多样性的影响。结果表明:与常规施肥相比,施用2种改良剂使根际土壤pH和EC值、K^(+)和Na^(+)含量降低,进而影响了土壤微生物多样性。盐碱胁迫下土壤微生物优势菌门主要为变形菌门、酸杆菌门、放线菌门和芽单胞菌门,盐胁迫下添加有机高分子复配材料和以黄腐酸为主的复合材料型改良剂的处理后,土壤中放线菌门和厚壁菌门的相对丰度增加,碱胁迫下施用2种改良剂后,变形菌门、酸杆菌门和疣微菌门的相对丰度增加。盐化和碱化土壤中微生物多样性丰富,优势菌群相对稳定,并且在添加改良剂后盐化土壤的耐受性比碱化土壤的更高;有机高分子复配材料和以黄腐酸为主的复合材料的应用可以通过改变土壤微环境进而影响菌群丰度。

Field experiments using barrels were conducted to explore the effects of two modifiers(organic polymer and fulvic acid-based composite) on soil physicochemical properties and bacterial community diversity in salinized and alkalized cotton-field soils.The results showed that compared with conventional fertilization, the application of the two modifiers reduced the pH,EC,and K^(+)and Na^(+)content of rhizospheresoil, affecting soil microbial diversity.The dominant phyla of soil microorganisms in salinized and alkalized soils were Proteobacteria,Acidobacteria,Actinomycetes,and Blastomonas.The application of the two modifiers increased the relative abundances of Actinomycetes,and Firmicutes in salinized soil, and the relative abundances of Proteobacteria,Acidobacteria,and Verrucomicrobia in alkalized soil.Insummary, the microbial diversity in salinized and alkalized soils were abundant, the dominant bacteria were relatively stable, and the tolerance to saline stress was higher than that to alkaline stress after applying the two modifiers.The application of organic polymer and fulvic acid-based composite affected the relative abundance of soil bacteria through changing the soil microenvironment.