Abstract:In order to find out the effects of different water and nitrogen coupling models on rice yield formation and nitrogen absorption and utilization in black soil area, three irrigation models, i.e., conventional flooded irrigation (F), shallow wet irrigation (W) and controlled irrigation (C), and four nitrogen application levels, i.e., 0kg/hm2, 85kg/hm2, 110kg/hm2 and 135kg/hm2(N0, N1, N2, N3), were set up in the experiment. The effects of different water and nitrogen coupling models on dry matter, yield, nitrogen uptake and transport, water and nitrogen use efficiency of rice were studied. The results showed that under conventional flooded irrigation and shallow wet irrigation, dry matter accumulation was increased with the increase of nitrogen application rate, while under controlled irrigation, dry matter accumulation was firstly increased and then decreased with the increase of nitrogen application rate. The nitrogen accumulation in different organs of rice shoot was increased with the increase of nitrogen application rate. With the same nitrogen application level, the nitrogen accumulation in leaves, stem sheaths, and panicle of the controlled irrigation mode was increased by 27.80%~43.42%, 18.32%~24.97% and 13.85%~24.25% compared with conventional flooded irrigation, which was increased by 0.96%~13.18%, 10.73%~12.86% and 10.53%~12.61% compared with shallow wet irrigation. Under the three irrigation modes, the dry matter and nitrogen accumulation rates of rice shoot were increased with the increase of nitrogen application rate, and the controlled irrigation mode was higher than shallow wet irrigation and conventional flooded irrigation mode, and the initial peak of dry matter and nitrogen accumulation was advanced with the increase of nitrogen application rate. The peak time of the average nitrogen accumulation rate was 11.39d earlier than that of the average dry matter accumulation rate. Compared with conventional flooded irrigation and shallow wet irrigation, controlled irrigation was more beneficial to increase rice yield, and CN2 treatment had the highest yield, which was 10272.57kg/hm2. The controlled irrigation model significantly improved the agronomic N use efficiency and partial factor productivity of N. Under the same irrigation mode, the nitrogen transport rate in leaves and stem sheaths and the contribution rate of nitrogen transport in panicle were decreased with the increase of nitrogen application rate. There were significant positive correlations between rice yield and irrigation water use efficiency (IWUE), water use efficiency (WUE), agronomic N use efficiency and 100kg grain nitrogen uptake(P<0.01), and it was negatively correlated with grain production efficiency of nitrogen (P<0.01). Appropriate water and nitrogen coupling mode can increase rice yield and nitrogen absorption and utilization. Comprehensive consideration of CN2 treatment was the best water and nitrogen coupling mode.