The study looked at how different timings and amounts of nitrogen fertilizer affect soil nitrogen levels, wheat growth, and grain quality. They found that applying more nitrogen later in the season can help wheat plants take up more nitrogen and improve grain quality, but too much at the booting stage can reduce grain yield. The best nitrogen application ratio for good wheat yield and quality was found to be 5:3:2 for basal application, topdressing at jointing stage, and topdressing at booting stage.