Effects of Nitrogen Application Rates on the Physicochemical Properties of Modern Rice Cultivars: A Comprehensive Study

ABSTRACT Background and Objectives Limited research exists on investigating the comprehensive effects of nitrogen application on modern rice quality and, specifically, on instant rice. This study examines the impact of varying nitrogen application rates (NARs) (0, 90, 120, 150, 180 kg/ha) on nutrient composition and processing qualities in three modern rice cultivars. Key parameters, including amylose, protein, and lipid content, glass transition temperature ( T g ), chalkiness, kernel dimensions, color, pasting properties, head rice yield, and instant rice quality, were analyzed. Findings Results showed that increasing NAR increased protein and decreased amylose, with cultivar‐specific lipid variations. Higher nitrogen reduced whiteness and length‐to‐width ratios, enhanced starch stability, and increased pasting temperatures. The optimal head rice yield was observed at 120 kg/ha, while instant rice quality, including whiteness, texture, and rehydration, peaked at 90 kg/ha. Conclusions These findings indicate that moderate nitrogen levels enhance the quality of modern rice cultivars. Significance and Novelty The study provides practical guidance for nitrogen management in rice production which can be instrumental in preventing the overuse of nitrogen fertilizers while improving the overall rice quality.