新疆连作棉田土壤微生物数量动态变化

以新疆连作陆地棉吐絮期土壤为对象，采用稀释平板法测定土壤微生物数量变化趋势。结果表明：棉田土壤中微生物种群以细菌为主，其次为放线菌，真菌数量最少。不同连作年限，细菌数量随着连作年限的增加而逐渐减少，但连作10年后增加；真菌和放线菌数量总体呈增加的趋势；棉花枯萎病和黄萎病病原菌数量总体也呈增加的趋势；相同连作年限，土壤微生物种群结构变化不大。

Study on the Population Structure of Microorganisms and Their Dynamics in the Continuous Cropping Cotton Soil

Using continuously cotton - cropped soil as the test material, carrying out the dilution - plate method, the soil microorganisms were quantitated in this paper. The result indicated that bacteria accounts for the largest proportion in the cotton - cropped soil microorganisms, actinomyces the second and fungi the smallest proportion. In line with the time span of continuously cropping year, the amount of bacteria showed a trend of significant decrease whinlO years and a trend of increase in varying degrees with a time span of over 10 years ; the amount of fungi and actinomyces increased in varying degrees ; the amount of pathogenic bacteria fusarium and Vertieillium of cotton showed a trend of slight increase ; In line with the time span of the same cropping year, population structure of soil microorganism didnt vary conspicuously.