The study compared the effects of regular fertilizer and a special slow-release urea on the growth of rice plants and nitrogen use. For early rice, the slow-release urea led to higher stem numbers, better nitrogen content, and higher yields compared to regular fertilizer. The slow-release urea also had the highest nitrogen use efficiency. For later rice, there was no significant difference between the two fertilizers, but the slow-release urea had higher grain yields. Overall, using the slow-release urea can increase profits for double cropping rice and improve nitrogen use efficiency, helping to save resources and protect the environment.