湘南地区烟稻轮作和不同年限烟薯套种对土壤微生物的影响

Effect of Tobacco-rice Rotation and Different Years Tobacco-potato Interplanting on Soil Microorganisms in Southern Hunan

对湘南地区烟稻轮作和不同年限烟薯套种的烟田土壤中细菌、真菌、放线菌进行分离培养,对微生物不同种群的数量进行分析,结果表明:烟薯套种在10年内土壤中可培养细菌与放线菌数量均为递增趋势,10年以后又呈递减的变化趋势,通过与水稻轮作,烟田土壤中可培养细菌、放线菌数量又呈明显增加;烟薯套种中随着套种年限的延长土壤中可培养真菌数量呈明显的递增状态,通过与水稻轮作,土壤中可培养真菌数量有了较为明显的减少。对微生物量C/N分析结果表明,烟薯套种10年内土壤中微生物量碳与微生物量氮均呈递增趋势,在10年以后为递减趋势;烟稻轮作相较烟薯套种明显使土壤中微生物量碳与微生物量氮增加。

Soil bacteria, fungi and actinomycetes in tobacco - rice rotation and different years tobacco - potato interplan- ring field in Southern Hunan were isolated and cultured, and then the quantities of microbes of different populations were analyzed, and the results showed that： soil cuhurable bacteria and aetinomyces in tobacco -potato interplanting field showed increased trend within 10 years, then showed decreased trend over 10 years, while quantities of euhurable bacteria and microbe showed obviously increased trend after rotation planting with rice. Quantity of cuhurable fungi in tobacco - po- tato interplanting field was increased with the increment of interplanting years, while it was decreased after rotation plant- ing with rice. Analysis on microbial biomass C/N showed that microbial biomass carbon and microbial biomass nitrogen were increased in tobacco - potato interplanting field within l0 years, and then decreased year by year. Soil microbial bio- mass carbon and microbial biomass nitrogen in tobacco - ice rotation field were higher than those in tobacco - potato inter- planting field.