The researchers studied how applying nitrogen to superhigh-yield winter wheat affects the photosynthesis of its leaves during the flowering stage. They measured various parameters like photosystem efficiency and leaf photosynthesis using a portable device. The results showed that the fluorescence and photosynthesis of the leaves were influenced by nitrogen levels. With the right amount of nitrogen, the leaves were better able to adapt to changing conditions and protect themselves. The highest grain yield was seen with an application of 300 kg/ha of nitrogen.