The timing of nitrogen fertiliser application to spring barley doesn't significantly affect grain yield or protein concentration. Whether the nitrogen is applied at sowing or crop emergence, or if the application is split, the results are similar. Even delaying a portion of the nitrogen until after the tillering stage doesn't have a consistent impact on yield or protein concentration. In conclusion, the majority of nitrogen should be applied before the end of the tillering stage for the best results in spring barley production.