中文摘要：

以河北省徐水县长期定位试验田为试验对象,利用末端限制性酶切片段多态性分析（T-RFLP）与构建氨单加氧酶基因（amo A）克隆文库的方法,探究了不同灌溉制度（CK：清水灌溉;CF：无机肥灌溉;T1、T2、T3、T4、T5、T6：不同浓度的牛场肥水灌溉）下,0～20 cm与20～40 cm两个土层中氨氧化细菌（Ammonia-oxidizing bacteria,AOB）的群落结构和多样性。根据AOB的末端限制性酶切片段多态性结果显示,在两个不同的土层中,T1处理（N 105 kg/hm^2,P2O539 kg/hm^2,清水∶沼液=2∶1）的Shannon-Wiener指数和Pielou指数均为最高,T4处理（N 420 kg/hm^2,P2O5156kg/hm^2,清水∶沼液=2∶1）的均为最低,且0～20 cm土层的多样性指数比20～40 cm土层的多样性指数高。表明牛场肥水的浓度同为2∶1时,多次灌溉会降低AOB的群落多样性,且表层土的AOB群落多样性要高于深层土的AOB群落多样性。基于amo A基因的系统发育树显示,0～20 cm土层中AOB主要属于亚硝化螺菌属（Nitrosospira）和亚硝化单胞菌属（Nitrosomanas）;20～40 cm土层中AOB则全部属于亚硝化螺菌属（Nitrosospira）,说明不同土层之间的氨氧化细菌群落结构存在差异。

英文摘要：

Ammonia-oxidizing bacteria （AOB） play an important role in the Biochemical cycle of N element. AOB is closely related to green- house gas emissions, soil quality. So, it＇s necessary to study the diversity and composition of soil AOB and get some soil quality monitoring. This study has designed eight fertilization treatments, including control without fertilizers （CK）, conventional fertilization （CF N 300 kg/ hm^2） and cattle fertilizer irrigation treatments in six fertilizer levels （T1 N 105 kg/hm^2, T2 210 N/kg/hm^2, T3 N 315 kg/hm^2, T4 N 420 kg/ hm^2 ,T5 N 317 kg/hm^2, T6 N 126 kg/hm^2）, through the way of terminal restriction fragment length polymorphism （T-RFLP） of amoA gene （ encoding ammonia monooxygenase）. The results of experiment show that： in two different soil layers, the soil under the T1 treatment of ammonia oxidizing bacteria Shannon Wiener index （H） and Pielou index （E） are the highest; T4 is the lowest treatment and the diversity index of 0-20 cm is higher than that of 20-40 cm layer; TI treatment is advantageous to the AOB community diversity and evenness, while T4 processing does not favor the AOB commonity diversity and richness; the phylogenetic tree based on AmoA gene shows that the AOB in 0 20 cm soil layer mainly belongs to Nitrosospira and Nitrosomanas, the AOB in 20-40 cm layer belongs to the Nitrosospira, which means that community relations between different layers are different.