Nitrogen accumulation and partitioning by the rice plant

or optimal management in rice (Oryza sativa L.) the producer must recognize differences in nitrogen (N) use relative to plant type, period of maximum recovery of N, and N losses by the plant. Field studies were conducted using standard-stature and semidwarf cultivars to evaluate dry matter and N accumulation and partitioning, to determine growth stage of maximum recovery of N under a dry-seeded culture system, and to estimate volatile N losses from rice foliage. Dry matter decrease after heading in vegetative tissues was higher with semidwarf 'Lemont' (27%) than with standard-stature 'Lebonnet' (20%). Both cultivars had similar patterns for total N (TN) partitioning at panicle differentiation; however, between heading and heading + 21 days (Hdg + 21D) Lemont showed a continuous N accumulation, but Lebonnet showed either a decline or a leveling. Fertilizer...