Background: Increased atmospheric nitrogen (N) deposition and altered precipitation regimes could change soil element availability and uptake by grassland plants. Identifying taxonomic or plant functional group-specific responses may provide a new perspective to explore the effects of N and water addition on community composition. Methods: Nitrogen addition and irrigation experiment was conducted using a split-plot design. We added 10 g N m− 2 yr− 1 twice per year and/or 15 mm of water once per week and cumulatively 180 mm during the growing season. We determined foliar concentrations of seven mineral nutrients (Ca, K, Mg, Cu, Zn, Mn, Fe) and one beneficial element (Na) in grassland plants. Results: Nitrogen addition as urea significantly decreased soil exchangeable Ca and Mg concentrations, but increased soil available Fe, Mn, and Zn concentrations, because of acidification. Under N addition, foliar Mn, Na concentrations increased, but foliar Fe concentrations decreased. Dicotyledons and sedges showed a stronger increase of foliar Mn and corresponding decrease of Fe concentrations than monocotyledons (without sedges) under N addition. Furthermore, Ca and K concentrations in monocotyledons and sedges increased, while that in dicotyledons remained unchanged under N addition. Conclusion: Our results suggest that the variations in foliar and soil element concentrations are mainly attributable to N-induced acidification. Meanwhile, irrigation increased the concentrations of base cations, weakening the impacts of N by alleviating soil acidification. The response of the nutrient concentrations in leaves to N addition varied among plant families and functional groups possibly contributing to changes in changes in plant community composition. [ABSTRACT FROM AUTHOR]