To investigate the effects of sources and timing of N application on wheat production and yield components, the experiment was conducted at the Agricultural Research Institute, Tarnab, Peshawar, during 2021–2022. Ammonium (NH4) and nitrate (NO3) were used as nitrogen sources, and they were supplied at a rate of 100 kg ha-1 at three separate phases, including the sowing (S1), tillering (S2), and boot stage (S3). Although it had no effect on the overall grain yield, ammonium N enhanced the yield component. Split N treatment enhanced the number of productive tillers per square metre and the weight of a thousand grains, whereas split N application at the tillering and boot phases boosted grain production. Regardless of when N was applied, nitrogen fertilisation enhanced grain production by 20% in comparison to control.

Keywords: Ammonium, fertilizer types, nitrate, wheat