【摘要】 研究了覆膜栽培条件下土壤微生物种群和生物活性．棕壤长期覆膜种植玉米，土壤表层微生物数量增多，细菌、放线菌和真菌分别增加２２．６％、２９．３％和１９．７％．苗期细菌增加最多，达２１４％，拔节期和成熟期放线菌增加最多，为２２４％和２４４％，生育期真菌增加幅度１２２～１４６％．细菌中兼厌气性种群优势有所增强，真菌优势种群无变化．肥力水平不同地块覆膜均加强土壤呼吸作用，高肥地块土壤脲酶活性升高，低肥地块无变化．更多还原

【Abstract】 Studies on the soil microbial population and biological activity in a brown earth continuously planted with corn and covered with plastic film show that after long term mulching, the numbers of bacteria, actinomyces and fungi in the topsoil increased 22.6%,29.3% and 19.7 %, respectively. At seedling stage, bacteria increased by 21.4%; at elongating and ripening stages, actinomyces increased by 22.4% and 24.4%, respectively; and within the whole growth period, fungi increased 12.2～14.6%. In addition, the dominant facultative anaerobial populations of bacteria tended to be increased, but those of fungi were not to be changed. Soil respiration rate was also enhanced by mulching in all sites with different fertility, but soil urease activity only increased obviously in the site with high fertility.更多还原