中文摘要：

采集小麦根际土壤,加入不同量的土霉素药物,使药物浓度为0、10、30、50、70 mg·kg^-1。利用平板菌落计数法,对不同浓度土霉素作用于根际土壤后两大类微生物（细菌、放线菌）数量进行了研究,探讨土霉素对小麦根际土壤微生物数量及活性的影响。结果表明,土壤微生物数目较原始土样有了较大的变化,细菌数目随药物浓度的增大数目整体呈减少趋势,在10 mg·kg^-1、30 mg·kg^-1土霉素条件下有较明显的减少,50 mg·kg^-1时略有上升,后继续减少;放线菌数目整体呈上升趋势。在不同土霉素浓度的作用下,碱性磷酸酶活性明显降低,对脱氢酶略有影响,对脲酶影响不大,其中碱性土壤中碱性磷酸酶活性比酸性土壤高。但随着培养时间的增长,各种酶活又逐渐恢复。

英文摘要：

Wheat rhizospere soil was collected and added different amount of terramycin,making the concentration be 0,30,50,70 mg.kg^-1.The effect of different concentration of terramycin on the soil microbes（including bacteria and actinomycetes） was investigated,using colony-counting methods,in order to assess its influence upon the microbial number in rhizosphere soil.The results showed that the number of soil microbes were greatly changed.The number of bacteria reduced as the concentration increasing.It had more significant effect on the concentration of 10 mg·kg^-1,30 mg·kg^-1 and increased a little in the concentration of 50 mg·kg^-1,then continuously reduced.The number of actinomycetes was increased as the concentration increasing.In the effect of the different concentration of terramycin,the activities of alkaline phosphatase reduced obviously,it did slightly influence to the desaturase while nearly did no influence on urinary enzyme.The activities of alkaline phosphatase was much higher than that of acid phosphatase in alkali soils.But along with the time raise,the enzyme activities of each kind recovered gradually.