Optimized nitrogen managements and polyaspartic acid urea improved dry matter production and yield of indica hybrid rice

Abstract Reasonable management of nitrogen (N) and the development of N fertilizers with higher use efficiency are the two main methods to increase rice yield. The effects of optimized nitrogen management (ONM) and polyaspartic acid urea treatment (PAU) on rice dry matter production and grain yield under different soil conditions in Sichuan, China, were studied in 2013. When the different N management regimes were applied there were differences in the rice tiller number, dry matter production, and yield observed. At Shehong, ONM3 (a 15% increase in the N rate over the farmer’s fertilizer practice) had the highest grain yield, and significantly ( P P P