Effects Of Two Microbial Agents And Organic Fertilizer On Soil Microbial Community And Its Functions In Continuous Cropping Strawberry Garden

Soil continuous cropping obstacles are common problems in the cultivation of greenhouse crops.The occurrence of these problems is closely related to soil nutrient imbalance,microbial community structure abnormalities and root exudates self-toxicity.Continuous cropping obstacles lead to slow growth of plants and increased soil-borne diseases,which bring huge economic losses to the agricultural industry.Soil microbes perform various ecological functions in the soil ecosystem,affecting soil nutrient conversion,degradation of toxic and harmful substances,and colonization of pathogenic microorganisms.By regulating soil microbial community structure,soil continuous cropping obstacles can be effectively alleviated.In this paper,the strawberry continuous cropping soil in greenhouse is used as the research object.By applying EM microbial agent and Bacillus subtilis(BS)bacteria and setting different quality organic fertilizers,the purpose is to regulate the microbial community structure and control the quantity of soil pathogenic microorganisms.Planting provides theoretical and practical basis.The specific research results of the thesis are as follows:1?At the 97%sequence similarity level,3888 OTUs were identified by bacterial 16S rRNA sequence,and 1234 OTUs were found in the fungal ITS sequence.EM1 treatment can reduce the species richness and diversity of soil bacterial communities,while EM2 and BS1 treatment can significantly increase bacterial species richness and diversity.The application of EM,BS bacteria+organic fertilizer in strawberry soil had no significant effect on the overall fungal community richness and diversity.2?the five treatments of strawberry continuous cropping bacteria in the soil are divided into 13 dominant gates(>1‰),of which Acidobacteria,Gemmatimonadetes,Deinococcus-Thermus,Microcytobacteria(Verrucomicrobia and Nitrospirae were significantly different between treatment groups(p<0.05).Seven fungal dominant gates(>1‰)were obtained from the five treated soils,and they were not significantly different among the different treatment groups.3?At the genus level,there are 20 dominant genus(>1%)in five strawberry soils,and Rhodanobacter,Bacillus and Arachidicoccus are dominant.Among the fungi,26 dominant genus(>1‰)were found.The higher abundance in the soil was Mortierella and Aspergillus.Only Plectosphaerella and Talaromyces were significantly different in soil samples.Four common plant pathogens were identified,and the total abundance of pathogenic bacteria was reduced when EM and BS agents+organic fertilizer were applied.Three of them were dominant genus,and Pseudomonas and Streptomyces were significantly different among different groups.The application of two microbial agents+ organic fertilizers was effective in reducing Streptomyces.There were 9 genus of plant pathogenic fungi,and the total abundance of phytopathogenic fungi was significantly reduced when EM1,B1,and BS2 were applied,from 9.95%in the control to 0.90%in EM1.There are 7 dominant genus of plant pathogenic fungi(>1‰),and the application of EM1 and BS1,BS2 significantly reduced the abundance of Rhizopus.BS2 treatment significantly reduced Penicillium abundance.The application of two microbial agents+organic fertilizers was effective in reducing the genus Fusarium and Alternaria.EM1 treatment significantly reduced the positive and negative relationship between the dominant genus and the pathogenic fungus.It is indicated that the bacterial agent plus organic fertilizer significantly affects the interrelationship between the dominant fungi of the fungus.4?Multivariate analysis showed that the order of environmental factors affecting the distribution of bacteria was TK>VP>TN>NH4+-N,which were the main environmental factors affecting bacterial communities;soil VP and C/N were the main environmental factors affecting the changes of fungal communities.5?The FAPROTAX function predicts that the application of BS2 significantly promotes the aerobic nitrite oxidation and nitrification functions.Both BS agent application rates significantly increased the cellulose hydrolysis function.Both EM agent applications significantly reduced bacterial fermentation function.FUNGuild predicts the function of fungal microbial community and finds that the application of microbial agents has significant effects on saprotroph and pathotroph functional fungi.In Guild's prediction,the application of fungicide+organic fertilizer had significant effects on Plant_Pathogen,Animal_Pathogen,and Soil_Saprotroph functional fungi.In summary,the two microbial agents and organic fertilizers have different effects on soil microbial community composition and ecological functions,and have certain inhibitory effects on some plant pathogenic bacteria and fungi.Different species and concentrations can be applied differently.To improve the microbial community structure and ecological functions to a less extent,and to slow down the continuous soil barrier,there is a certain potential for application.