Nitrogen (N) is a necessary element of soil fertility and a limiting nutrient in tallgrass prairie but grazers like bison and cattle can also recycle N. Bison and cattle impact the nitrogen (N) cycle by digesting forage that is consumed, and recycled back to the soil in a more available forms stimulating soil microbial N cycling activities. Yet we do not know how both grazers comparatively affect N cycling in tallgrass prairie. Thus, we investigated if bison and cattle had similar impacts on N cycling in annually burned tallgrass prairie relative to ungrazed conditions over a 3-year period (2020–2022) at the Konza Prairie Biological Station. We examined: soil pH, soil water content, mineralized N, nitrification potential, denitrification potential and extracellular enzyme assays. Interannual variability in precipitation controlled soil water and N cycling microbial activities but grazing effects had a stronger influence on N cycling. We found significant differences and increased soil pH, nitrification and denitrification potential and less N limitation in bison vs cattle grazed soils where bison grazed soils exhibited faster N cycling. Differences between the grazers may be attributed to the different management of bison and cattle as both can impact N cycling. Overall, these data provide some evidence that bison and cattle affect N cycling differently at this study site, and improve the ecological understanding of grazer impacts on N cycling dynamics within the tallgrass prairie ecosystem.

氮 (N) 是土壤肥力的必要元素，也是高草草原的限制性养分，但野牛和牛等食草动物也可以循环利用氮。野牛和牛通过消化消耗的草料并循环回到氮 (N) 循环，从而影响氮 (N) 循环。土壤以更有效的形式刺激土壤微生物氮循环活动。然而我们不知道这两种食草动物如何相对影响高草草原的氮循环。因此，我们在孔扎草原生物站调查了三年期间（2020-2022），相对于未放牧的条件，野牛和牛对每年被烧毁的高草草原的氮循环是否有类似的影响。我们检查了：土壤 pH 值、土壤含水量、矿化氮、硝化电位、反硝化电位和细胞外酶测定。降水的年际变化控制着土壤水和氮循环微生物活动，但放牧效应对氮循环的影响更大。我们发现，与牛放牧的土壤相比，野牛放牧的土壤存在显着差异，土壤 pH 值、硝化和反硝化潜力增加，氮限制更少，其中野牛放牧的土壤表现出更快的氮循环。食草动物之间的差异可能归因于野牛和牛的不同管理，因为两者都会影响氮循环。总体而言，这些数据提供了一些证据，表明野牛和牛在该研究地点对氮循环的影响不同，并提高了对高草草原生态系统内放牧动物对氮循环动态影响的生态理解。