【摘要】 对烟草不同连作年限的烟田土壤中细菌、固氮菌、放线菌和真菌进行分离,对微生物不同种群进行数量和多样性分析。结果表明,在连作10年内,细菌的数量随着连作年限的延长而增大;连作年限在10年以上,细菌数量随着连作年限的延长而呈现减小趋势;在连作15年内,固氮菌和放线菌数量随着连作年限的延长而增大。连作年限在5年以内,根际土和非根际土中微生物多样性指数H和均匀度E随连作年限的延长而增大,连作年限在5年以上,根际土和非根际土中微生物多样性指数H和均匀度E随着连作年限的延长而呈现减小趋势。更多还原

【Abstract】 The effect of continuous tobacco cropping on the microbial quantities in tobacco soil was studied.Results showed that the quantities of bacteria,azotobacteria,actinomycetes and fungi were obviously affected in tobacco soil by the continuous tobacco cropping,with year increasing of replanting,the number of bacteria showed a trend of increasing under ten years of continuous tabacco cropping and then decreasing afterward,the number of azotobacteria and actinomycetes showed a trend of increasing under fifteen years of continuous tabacco cropping.Results also showed that microbial diversity index H and E showed a trend of increasing under five years of continuous tabacco cropping and then decreasing afterward.更多还原