Ammonia-oxidizing bacterial communities are affected by nitrogen fertilization and grass species in native C ₄ grassland soils

Abstract

<i>Nitrosospira</i> were dominant AOB in the C₄ grassland soil throughout the growing season. N fertilization rate had a stronger influence on AOB community composition than C₄ grass species. Elevated N fertilizer application increased the abundance, activity, and alpha-diversity of AOB communities as well as nitrification potential, nitrous oxide (N₂O) emission and soil acidity. The abundance and species richness of AOB were higher under switchgrass compared to big bluestem. Soil pH, nitrate, nitrification potential, and N₂O emission were significantly related to the variability in AOB community structures (<i>p</i> < 0.05).