Farmland is one of the most important sources of greenhouse gas emissions, and as global warming becomes more and more serious, greenhouse gas emissions from farmland are of increasing concern. The vast majority of the land in the North China Plain is dryland, and the main greenhouse gas emitted from dryland is N₂O. It is mainly driven by ammonia oxidizers. Ammonia oxidizers convert ammonium (NH₄⁺) in the soil to nitrite (NO₂^-), which is eventually converted to other forms of nitrogen, including N₂O. As a result, ammonia oxidizers have received more and more attention from researchers in recent years. Based on a field localization experiment, we investigated the community composition and diversity of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) of winter wheat in rhizosphere and bulk soils in five crop rotations: summer adzuki bean-winter wheat, summer mungbean-winter wheat, summer peanut-winter wheat, summer soybean-winter wheat, and summer maize-winter wheat (as the control group). Results showed that the legume-based rotations increased soil organic carbon and nitrate contents in rhizosphere soils and increased total nitrogen and ammonium contents in bulk soils compared with winter wheat-summer maize, respectively. The legume-based rotations universally reduced Abundance-based Coverage Estimator (ACE) and Chao1 indexes of AOA communities in bulk soils. They significantly reduced ACE and Chao1 indexes of AOB communities in rhizosphere soils (P<0.05). Moreover, the legume-based rotations significantly increased the relative abundance of Crenarchaeota and Proteobacteria for AOA and AOB communities, respectively. Specifically, the relative abundance of OTU58 (Crenarchaeota) in the AOA community and the summer adzuki bean-winter wheat and summer mungbean-winter wheat patterns significantly increased the relative abundance of OTU76, OTU95, and OTU3 (Proteobacteria) in the AOB community, respectively (P<0.05). The AOA community structures were significantly separated between the legume-based rotations and winter wheat-summer maize in rhizosphere soils. In contrast, the AOB communities were separated between the legume-based rotations and winter wheat-summer maize in bulk soils (P<0.05). Increased soil pH and organic carbon content in rhizosphere soils were important environmental drivers for the separation of AOA community structures. In contrast, changes in total nitrogen and ammonium nitrogen content in bulk soils were the main environmental drivers for the separation of AOB community structures. Our findings indicated that the structure and diversity of AOA and AOB communities were altered by legume-based rotations, and soil pH and available nitrogen content were the driving factors. Additionally, there was an ecological niche separating AOA and AOB in rhizosphere and bulk soils.