Effect of water and nitrogen coupling on root morphology and physiology, yield and nutrition utilization for rice

The purposes of this study were to investigate the effects of water and N coupling on root morphology and physiology, grain yield and N fertilizer use efficiency. A mid-season japonica rice cultivar of Xudao 3 was planted. Three treatments of different N levels, i.e. no N fertilizer application, normal N (MN, 240 kg/km super(2)) and high N (HN, 360 kg/hm super(2)) and 3 irrigation regimes, i.e. submerged irrigation (0 kPa), alternate wetting and moderate drying (-20 kPa) and alternate wetting and severe drying (-40 kPa) were conducted. The results showed that there was a significant interaction between irrigation regimes and N applications, while not significant between the years for the main indices.