The study looked at different types of Indica rice to see how efficiently they use nitrogen. They tested both regular varieties and hybrid combinations in a pot experiment. Results showed that the efficiency of nitrogen use varied among the different types of rice. Regular varieties had higher nitrogen use efficiency than hybrid combinations. As the rice plants grew, their nitrogen use efficiency increased. Hybrid combinations had lower nitrogen use efficiency but higher grain production efficiency. The amount of nitrogen in the plants and grains was closely related to the final yield of rice.