Effects Of Organic Materials Addition On Microbial Communities In Salinized Soil

Due to the unique climate,hydrology,geology,other geographical conditions and unreasonable irrigation methods in tumechuan plain of Inner Mongolia,not only the soil nutrient content is low and the degree of salinization is deepened,but also the diversity and structural composition of soil microbial communities are changed,which seriously restricts the agricultural production in this area.Therefore,Five different treatments were selected,including blank(CK),biochar(BC),cow dung(CD),corn straw(SW)and sheep manure control(GM).The effect of organic material addition on the diversity and structural composition of bacteria and fungi communities of alkaline soil by using high throughput sequencing technology,and the effects of chemical properties and enzyme activities on soil microbial communities.The main results and conclusions of this paper are as follows:(1)Adding organic materials could change the diversity and structure of soil bacterial communities,and adding cow dung(CD)had the higher richness and diversity of bacterial community.The dominant groups of soil bacteria under different treatments were Proteobacteria(38.03%?47.75%)and Sphingomonas(8.51%?12.64%),respectively.The adding of sheep manure(GM)and cattle manure had a greater impact on Proteobacteria,and biochar(BC)had a greater impact on Sphingomonas.Biochar addition could increase the relative abundance of beneficial bacteria,such as Proteobacteria,Bacteroidetes and Gemmatimondetes.All treatments reduced the relative abundance of E6067 of harmful bacteria.OTU?9180 ? OTU?2031 ? OTU?2561 ?OTU?8046?OTU?600 and out?4632 at Proteobacteria level,OTU?1082?OTU?5936 and OTU?711 at Firmicutes level and OTU?1785 at Acidobacteria level can be used as an indicator of bacterial community structure.(2)The addition of organic materials could change the diversity and structure of soil fungi communities.The higher richness of fungi communities was found in adding cow dung,and the higher diversity was found in adding biochar.The dominant groups of soil fungi under different treatment were Ascomycota(36.33% ? 57.87%)and Chaetomium(2.76% ? 8.29%),respectively.Adding sheep manure and biochar treatment had a greater impact on Ascomycota,while cow manure treatment had a greater impact on Chaetomium.All treatments could increase the relative abundance of Ascomycota of beneficial fungi,while straw addition could reduce the relative abundance of harmful fungi,such as Zygomycota and Fusarium.OTU?109 and OTU?931 at the level of Chytridiomycota,OTU?545 and OTU?263 at Zygomycota level,OTU?215?OTU?617?OTU?451 and OTU?1287 at Ascomycota level can be used as an indicator of fungi community structure.(3)Compared with the control,the content of soil organic carbon,soluble organic carbon,microbial biomass carbon,total nitrogen and invertase activity of each treatment were improved in varying degrees.After comprehensive consideration,the short-term experimental results showed that the effect of sheep manure on soil improvement was better,and the maize yield of sheep manure treatment was higher.(4)Soil invertase(INV),catalase activity(CAT),p H,alkalinity(ESP),microbial biomass carbon(MBC)and organic carbon(SOC)contents were important factors affecting bacterial community structure(phylum and genus level);Soil p H,electrical conductivity(EC),soluble organic carbon(DOC),available phosphorus(AP),catalase activity(CAT)and organic carbon(SOC)content were important factors affecting fungi community structure(phylum and genus level).In conclusion,It is of great significance to understand the diversity and structural composition of soil microbial communities,and improve the quality of salinized soil and increase crop yield in Tumochuan Plain.In this study,the experimental period is short,and long-term observation is needed after adding organic materials to further study the interaction between organic materials and soil microbial community.