Effects Of Fumigation And Inoculation On The Structure And Function Of Soil Microbial Community

Soil microorganisms are not only an important part of the soil,but also play a vital role in soil structure,fertility formation,crop yield,soil pollutant degradation and soil self-purification.Probing the structure and function of soil microbial communities,and deeply understanding the role of different microorganisms in soil material circulation and their ecological functions have always been hot issues in soil microbiology,ecology and environmental studies.Soil fumigation and inoculation of cultivable microorganisms are not only commonly used agricultural production techniques for soil-borne disease prevention and control,improving soil nutrient utilization and improving crop nutrition,but also for us to study and evaluate the role and function of different soil microorganisms in soil material circulation Provides new research methods and ideas.In this study,typical black soil was used as the test soil,and high-throughput sequencing technology was used to separate the test black soil and the plate to obtain the community structure characteristics of cultivable microorganisms;the influence of fumigation and different inoculation treatments on the soil microbial community structure;different soil microorganisms Preliminary studies have been carried out on four aspects,including the role of soil groups in the transformation of soil N,P,and K;the effects of different soil microbial groups on the growth and development of test crops.The results of the research are as follows:(1)The total number of operational taxonomic units(OTU)of prokaryotic soil microorganisms in the black soil "culturable amplification group" and "soil amplification group" is 2900,of which the cultivable microorganism amplification group has 135 OTUs,and the soil expansion group has 135 OTUs.The number of OTUs in the increased group is 2862,and the total number of OTUs shared by the two is 97;the total number of OTUs of eukaryotic soil microorganisms is 795,including361 in the cultivable group and 737 in the soil amplification group.The operational classification unit shared by the two is 303.Among them,the types of cultivable prokaryotic microorganisms are 4.66%,the types of non-culturable microorganisms are about 95.34%,the types of eukaryotic microorganisms that can be cultured are32.88%,and the proportion of non-culturable microorganisms is 67.12%.The results of the study show: The type and quantity of microorganisms may be underestimated.(2)In the analysis of species composition,the annotation result of the soil amplification group is greater than that of the cultivable amplification group.The top five dominant species in abundance analysis share prokaryotic microorganisms:Bacillus,eukaryotic microorganisms: Mortierella Genus(Mortierella),Humicola(Humicola),the top 20 abundance species have the same annotation results,only the abundance is different;from the perspective of flora function,the prokaryotic microbiome can be cultured and amplified group annotation results are in the main The abundance of functional genes is greater than the annotation results of the soil amplification group,and the overall gene types are more abundant in the soil amplification group.The annotation results of the cultivable amplification group in the eukaryotic microbiome are much lower than the soil amplification group,but they are not lost.The function of the main abundance flora,this result suggests that the function of cultivable microorganisms may be underestimated.(3)Both fumigation and inoculation will affect the Alpha diversity of soil microbial populations.Fumigation does not cause differential changes in the Alpha diversity of soil prokaryotic microbial community populations,but changes the Alpha diversity of eukaryotic microbial community populations.The inoculation treatment reduces the Alpha diversity of prokaryotic microorganisms,causes 60% differences in dominant species,and causes differential changes in Beta diversity,but does not have a significant impact on eukaryotic microorganisms.(4)Combined with the analysis of related influencing factors,the results of the effects of fumigation and inoculation treatments on soil nutrients show that: the microorganisms of the cultivable amplification group play an important role in the transformation of soil total phosphorus,available phosphorus,and total nitrogen;soil amplification group The microorganisms play an important role in the conversion of alkaline hydrolysis nitrogen,available potassium,available phosphorus,and total nitrogen;the remaining(not killed)microorganisms after fumigation treatment have less significant effects on nutrient conversion than the former two.(5)In terms of soil fertility quality indicators,combined with the research results of RDA redundancy analysis,it is shown that the cultivable and amplified group of microorganisms is affected by the community structure of soil microorganisms,that is:whether the cultivable microorganisms can colonize the soil after inoculation with soil bacteria,Actinomycetes and fungi's community structure.The microorganisms of the soil amplification group are affected by soil nutrient content(fertilization);the remaining microorganisms of fumigation are not affected by the microbial community and nutrient changes.In terms of soil ecosystem stability,soil samples composed of cultivable and amplified microbial flora have better ecological stability,strong ability to resist external interference factors,and can protect the soil environment to the greatest extent and reduce damage.(6)Soil fumigation does not change the structure of the soil's inherent microbial community,but inoculation will change the soil's inherent microbial community structure and cannot be restored to the original level.That is: the overall structure of the soil community after the fumigation "restoration" is similar to that of the original soil sample.There is no difference in pronucleus and a small amount of difference in eukaryotes.However,even if the soil sample treated with inoculation has passed for a period of time,the state after "stabilization" does not matter whether it is eukaryotic or eukaryotic.Prokaryotic microorganisms are different from the original soil samples.(7)For soil samples treated with fumigation and inoculation,in the comprehensive evaluation of harvested crops,the soil treated by cultivating the amplified group of microorganisms is more conducive to crop growth.Fumigation of the remaining microorganisms treats the soil,because a large number of pathogens have been removed artificially.The harvest result is better than the original soil;Based on the above results,there are differences in the identification results of pure culture technology and amplified omics technology.The microbes it characterizes have different effects in the soil samples processed by them,resulting in significant differences in the results.From a research perspective,in soil microbial analysis The above single detection method cannot prove its full effect,and a variety of methods should be combined to perform more complete analysis and processing to produce comprehensive and true data and conclusions.Both fumigation and inoculation will have varying degrees of impact on the soil microbial community structure.Fumigation treatment tends to affect soil eukaryotic microorganisms,and inoculation treatment favors the impact on soil prokaryotic microorganisms.After a buffer period,it is found that the inoculation treatment will affect the soil eukaryotic microorganisms.Soil microbes cause irreversible changes,and the soil microbes treated by fumigation are similar to the original soil as a whole.Changes in soil microbial community structure lead to changes in soil fertility and functions,which in turn affect the effect of soil in practical applications.The soil planting effect of inoculation treatment is better It is used for fumigation treatment of soil,and the planting effect of fumigation treatment soil is better than that of original soil.