Nitrogen treatments play a crucial role in boosting the yield of summer maize. By studying different nitrogen levels on three maize hybrids, researchers found that the optimal nitrogen application for maximum yield was around 450kg·ha-1. This level increased photosynthetic rate during the flowering stage and improved dry matter accumulation. Maize populations treated with 450kg·ha-1 nitrogen had higher dry matter production and better growth potential. To achieve super high-yield maize, it is important to enhance photosynthesis during the filling stage, delay the peak dry matter accumulation, and increase dry matter accumulation early on with nitrogen treatment.