The study looked at how different amounts of nitrogen fertilizer affect corn growth and yield in a mountain area in northwest Guizhou. They found that the best nitrogen application rate for highest yield was around 563.76kg/hm2. Increasing nitrogen fertilizer within a certain range improved leaf area, chlorophyll levels, kernels per spike, dry matter accumulation, and yield. However, going beyond this range decreased yield. The study suggests that applying 637.23kg/hm2 of nitrogen fertilizer could result in a theoretical yield of 9,177.69-12,175.47 kg/hm2.