Effect Of Manuring On Soil Microbial Community Diversity In Organic Production Of Pear Orchard

In order to investigate the parameter of soil microbial community and the short effect of manuring treating, the amount distributing, community parameter and dominant bacteria of soil microbe with different biologic and Organic manuring in different season in organic pear orchard of Shunyi, Beijing was researched using traditional cultivation and denaturing gradient gel electrophoresis method. The results were as follows:(1) Using traditional cultivation method, 289 bacteria, actinomyces and fungi strains with different morphological character of colonies were isolated and cultured. Configuration character and 16S rDNA sequences of dominant bacteria showed that Streptomyces, Bacillus, Pseudomonas, Micrococcus are major and representative bacteria groups in soil of Shunyi, Beijing. The analysis of diversity shows that some of the manuring treating will advance the soil bactrial community diversity index, evenness and richness which was high from the sample without manuring. Different manuring could increase the soil bactrial community parameter effectively but discrepantly. The environment factor such as temperature and rainfall can also affect the soil bacteria community parameter and community structure. Higher temperature and more water can increase the community parameter. Streptomyces and Bacillus are always existed in different seasons which are likely to the aboriginal population in soil bacteria community.(2) Using denaturing gradient gel electrophoresis technology, an investigation on the soil bactrial community diversity caused by twelve different manuring was carried out in Jinshiji organic pear orchard of Shunyi, Beijing. The community diversity index, richness and evenness were used to evaluate the effects of manuring on organic pear orchard soil ecosystem. The result indicated that the soil bactrial community diversity index and richness were both advanced discrepantly but the evenness had no distinct change two years later after different manuring on soil. Manuring could increase the soil bactrial community diversity effectively but discrepantly and maintain relative stability of community structure, which was related with the sort and quantity of the manure. A decreased degree was obtained in the order of two kinds of mixed organic manure>one kind of organic manure mixed with biologic manure>one kind of organic manure. There was no distinct difference between manuring one time and manuring two times on the same plot. Clustering analysis shows that the soils with similar manuring had higher bactrial community structure comparability.(3) The result of nutrition element in soil testing showed that the amount of total nitrogen, phosphorus, organic matter and the available potassiumin in soil are affected by the external fertilizer. Manuring accelerate the nutrition element amount of soil. The effect on organic matter and the available potassiumin in soil are obvious. The reason for this may be the different kind and amount of manuring. Besides, the amount of nutrition element in different soil samples have no relationship with the microbe number and the reason for this needs further discuss.