Physiological nitrogen efficiency in rice: Nitrogen utilization, photosynthesis, and yield potential

Characteristics of rice (Oryza sativa) as a crop plant are briefly introduced, and the relationship between formation of yield potential and nitrogen (N) nutrition is described on the basis of studies using 15N as a tracer. In addition, the relationship between the leaf photosynthetic capacity and leaf N, and the factors limiting leaf photosynthesis under different growth conditions are reviewed. Finally, targets for improving rice yield potential are discussed with a focus on the role of increased photosynthesis efficiency in relation to leaf N status and the photosynthetic components in the leaves.