The researchers studied how different amounts of nitrogen fertilizer and three soybean varieties affected the growth and yield of spring soybeans in Chongqing. They found that when Tedou No.5 soybeans were grown with 90 kg of nitrogen per hectare, they had higher seed nitrogen content, nitrogen utilization efficiency, and yield compared to other treatments. This combination resulted in a yield of 2,240 kg per hectare. Tedou No.5 had the highest nitrogen utilization efficiency, while Zhechun No.3 was more sensitive to nitrogen levels. The best yield was achieved when Tedou No.5 was grown with 90 kg of nitrogen per hectare.