Effects of water management patterns and nitrogen fertilizer levels on nitrogen use efficiency of rice

A two-year pot-culture experiment of rice cultivar, II You 838, with alluvial soil from Hubei was conducted to investigate the effects of two water management patterns and four nitrogen fertilizer levels on the aerial part biomass, nitrogen (N) accumulation, N use efficiency. The results show that the aerial part biomass, N accumulation and N use efficiency of rice are obviously affected by the water management patterns, and the rice grain yield, nitrogen accumulation, nitrogen agronomic efficiency, nitrogen recovery efficiency, partial factor productivity and nitrogen physiological efficiency under the water-logging irrigation pattern are higher than those of the water-controlled irrigation pattern. The biomass and N accumulation of rice aerial parts are increased with the increase of nitrogen level, while the nitrogen agronomic efficiency, partial factor productivity of the applied N and N physiological efficiency are reduced. However, there are no significant differences between the 25% N saving from conventional nitrogen application rate (N2) and the conventional nitrogen application rate (N3). In general, the water-logging irrigation pattern combined with the 25% N saving from conventional nitrogen application rate is recommended as a better water and nitrogen application patterns due to its higher grain yield and nitrogen utilization.