Effects Of EM On Microbial Diversity And Activity In Rhizosphere Soil Of Bletilla Striata

EM is a kind of high-efficiency compound microbial flora,which is widely used in cropping,aquaculture,environmental protection and other fields.This paper takes Bletilla striata as research object and studies the use of EM to improve soil fertility and disease in the continuous cropping process.The research results are as follows:1.The physicochemical properties of the rhizosphere soil of Bletilla striata treated with EM were determined by conventional methods.The nutrients in the rhizosphere soil of Bletilla striata were changed after spraying EM,The C,N,P and S elements in the soil increased by by 16.42%,21.08%,56.25%,40.91% respectively.continue to spray EM,C,N,P elements in the rhizosphere soil of Bletilla striata showed an increasing trend.2.The activity of soil enzymes in the rhizosphere of Bletilla striata treated with EM was determined by routine methods.The activities of enzymes in rhizosphere soil were significatly changed after spraying EM.Urease,invertase and catalase increased by 50.66%,23.19%,39.55%,polyphenol oxidase and peroxidase activities were reduced by 30.16% and 51.44% respectively.3.The effects of EM on the diversity of prokaryotic and eukaryotic microorganisms in the rhizosphere soil of Bletilla striata were analyzed by nonculture method.After EM treatment,the number of prokaryotic microorganisms in the rhizosphere of Bletilla striata was 356 genera in 27 phyla,which increased by 5 phyla 117 genera compared with the blank group.while that of eukaryotic microorganisms was 19 phyla 178 genera,which was 8 phyla 32 genera lower than that of blank group.4.Fourteen strains of bacteriostatic microorganisms were isolated from the rhizosphere soil of Bletilla striata by pure culture.The distribution of bacteria was classified into 4 phyla,7 genea and fungi were 2 phyla and 5 genera.Trichoderma asperellum,Pseudomonas sp.,Bacillus methylotrophicus,Bacillus subtilis and Pseudomonas sp.have obvious inhibitory effects on the pathogenic bacteria of Bletilla striata.Bacillus sp.and Pseudomonas sp.has obviou inhibitory effect on the pathogen of Bletilla striata leaf spot,Lsinibacillus sp.has obvious inhibitory effect on the pathogen of Bletilla striata leaf spot.EM can significantly reduce the speci-es and quantity of pathogenic microorganisms in the rhizosphere soil of Bletilla striata.