连作番茄保护地土壤微生物数量的时空变化

Study on Population Structure of Microorganism and Their Dynamics in Continuous Cropping Tomato Soil

[目的]为了研究微生物含量随保护地连作年限、土层深度及番茄生长期变化的规律。[方法]对番茄保护地连作5、10、20年以及连作10年中0～20、20～40、40～60 cm 3个层次的土壤微生物含量进行研究。采用稀释平板法测定土样微生物含量。[结果]所有土样中,细菌含量最多,其次是放线菌,真菌最少。保护地连作20年土壤细菌含量显著下降;连作10年土壤放线菌含量显著下降;连作10、20年土壤真菌含量差异不显著,且有上升趋势。0～20 cm土层微生物含量最高,随着土层加深呈下降趋势。20～40 cm土层细菌和放线菌含量下降明显;3个土层真菌含量间差异不大。在同一连作年限或同一土层中,不同番茄生长期显著影响微生物含量,苗期、开花坐果期番茄根围土壤中微生物含量在0.05水平显著高于结果期。[结论]连作年限、土层深度及番茄生长期显著影响根围土壤微生物含量,并且呈规律性变化。

[Objective] The research aimed to detect the microbial community of conservation tomato greenhouse soil of different years,different soil depth and different growth periods of tomato.[Method] The soil samples were collected from 0-20 cm layer of 5 years,10 years,20 years,and from 0-20 cm,20-40 cm,40-60 cm soil layers of soil conservation tomato greenhouse for 10 years.The total numbers of microorganism were detected by agar dilution method.[Result] In view of their total quantity,bacteria had the largest population,fungi had the least.The total number of bacteria decreased significantly in 20 years soil,and the total number of actinomyces has been raised significantly in 10 years soil.The total number of fungi in 20 years soil was more than in 10 years soil,and there were no significant difference between them.The total number of microorganism was highest from 0-20 cm soil layer,but the total number of fungi and actinomyces decreased significantly.The total number of fungi between three soil layers was no significant difference.The total number of microorganism was influenced by growth periods of tomato,and which was higher during seedling period and fruit-set period than maturity period.[Conclusion] The total number of microorganism was influenced significantly by continuous cropping years,depth of soil,and growth periods of tomato,and has regular variation.