Unveiling nitrogen preferences in indica rice: a classification study of cultivars in South China

These results demonstrate distinct responses of rice cultivars to different nitrogen treatments. Through correlation, principal component, and cluster analyses, the rice cultivars were categorized into three types: ammonium-preferring type (APT), ammonium- and nitrate-preferring type (ANPT), and nitrate-preferring type (NPT). The APT, ANPT, and NPT showed the highest biomass in the 100:0, 75:25, and 0:100 treatments, respectively, with the biomass in the ANPT significantly exceeding that of the APT (<i>p</i> < 0.01). These insights provide a foundation for breeding high-yield <i>indica</i> rice, optimizing nitrogen fertilizer strategies, and improving nitrogen use efficiency in sustainable agriculture.