不同连作年限下烤烟不同生育期土壤微生物区系动态研究

Dynamics of the Soil Microbial Flora at Different Growing Stages of Flue-cured Tobacco under Continuous Cropping Years

[目的]研究烤烟连作对土壤微生物区系动态的影响。[方法]采用盆栽试验,研究烤烟连作0、4、6和8年各生育期土壤微生物的变化规律。[结果]随连作年限的增加,各微生物数量在整个生育期表现:细菌和解磷细菌表现为升高—降低—升高的规律,真菌与之相反;放线菌和氨化细菌表现为先增加后降低的趋势,解钾菌与二者表现相反的规律;硝化细菌随连作年限的增加逐渐增加。各微生物随烤烟生育期变化:细菌、真菌、放线菌、氨化菌、解钾菌表现为先降低至末期又升高的趋势;硝化细菌和解磷菌表现为升高—降低—升高的趋势。[结论]土壤微生物活性与烤烟连作及烟草生长关系密切,研究连作和烟草生长发育对土壤微生物活性的交互影响更有意义。

[Objective] To study dynamics of the soil microbial flora at different growing stages of flue-cured tobacco under continuous cropping years.[Method]A pot experiment was conducted to study the variation of soil microroganism at tobacco developmental stages under different continuous cropping years. [Result]With the increase of continuous cropping ,the average anmout of bacteria and phosphate-dissolving bacteria showed increased lower increased downward trend, while the fungi reversed to the above;the actinomycete and ammonifier presented the trend of first increase then decreased, while the potassium-dissolving bacteria reverersed to the above; the nitrobacteria increased with the increased of continuous cropping. In whole developing stage of tobacco, the average number of bacteria, fungi, actinomycet, ammonifier and phosphate-dissolving bacteria of different treatments showed the trend of decreased first and then increased;the nitrobacteria showed the trend of increased-decreased-increased.[Conclusion] Soil microbial activity is closely related to tobacco continuous cropping years and tobacco growth, and it is more meaningful to study the interaction effect of continuous cropping and tobacco growth on soil microbial activity.