Abstract:In order to explore the effect of rice water consumption characteristics on WUE in cold black soil region, the experiment was carried out by lysimeter at the rice irrigation experiment station of Heilongjiang Province in 2017. The U7（76）experiment was conducted to analyze the variation regular of water consumption of rice stage water consumption, during daytime, nighttime and hourly at different growth stages, the effects of water consumption at different growth stages on WUEand biomass WUE were clarified. The results showed that water consumption and water consumption percentage were the highest at the jointing-booting stage, which were 77.25mm and 23.09%, respectively. The daytime and nighttime water consumption of rice showed a trend of “l(fā)ow-high-low”, The daytime and nighttime water consumption reached the maximum at the headingflowering stage, which were 6.32mm/d and 0.76mm/d,respectively. The water consumption characteristics of rice in the daytime showed an inverted “V” curve at the early and midtillering stage, the water consumption peak was at 12:00—13:00. It showed an “M” curve from the late tillering stage to the milky stage, the water consumption peak was at 11:00—12:00 and 13:00—14:00, respectively. The time of the maximum water consumption was at 10:00—11:00 during the milky stage. The direct effect of stage water consumption on WUEand the total contribution to R2 were consistent, and the order from large to small was ET5, ET2, ET4, ET3, ET6 and ET1. The water consumption at the late tillering and milky stage had a direct negative impact on WUE, the order of the determinant coefficient of water consumption in each stage on WUEwas ET5, ET4×ET5, ET2×ET5, ET2 and ET4. There were significant positive correlations between SWUE5 and rice yield and WUE, the effect order of water consumption on SWUE5 from the early tillering to heading-flowering stage was ET5, ET4, ET3, ET1 and ET2. The study would be helpful in understanding water consumption and water use efficiency of rice and formulating water-saving plan in black soil region.
