不同水分灌溉下的水稻生态效应研究

On Physiological Effect on Paddy in Different Mode of Irrigation

以大田水分控制方法设置4个不同的灌溉水分处理,旨在探究不同水分条件对水稻光合作用、蒸腾作用以及冠层温度的影响.结果表明各处理光合作用的日变化规律表现为晴天天灌的“长峰距”特点,光合速率以淹灌最强,天灌最弱;光合“午睡”现象因日照条件而变化,晴天较阴天严重,但晴天和阴天有不同的特点,晴天天灌上午的峰值提前,下午推后,阴天不出现峰值的移动.蒸腾速率以淹灌的最大,天灌最小;晴天蒸腾速率日变化有“午睡”现象,阴天为单峰型.4处理中以天灌的冠层温度最高,淹灌最低,湿灌和配灌区别甚微;早晚时分温度趋同,中午时分温差拉大.

Some of the ecological effects under 4 different irrigated patterns [basin irrigation(BI),Normal irrigation(NI), controlled moist irrigation(CI), rain-fed paddy field(RI)] also studied in this paper.The experimental results showed that the effects of different irrigated patterns varied obviously.Water stress could affect the photosynthesis,transpiration,canopy temperature and so on.①Photosynthesis:BI possessed the highest conoly photosynthetic rate in the booting stage which could reflect the accumulative effect to water stress,and RI had the opposite result.The diurnal changes of photosynthetic rate fitted a double peak curve no matter whether it is sunny or cloudy.In sunny days the peaks deferred than that of cloudy days?in the condition of normal water.However,in sunny days RI which was subjected to the most seriously water stress reached the first peak earlier than that of the cloudy days and the second peak defers to that of the cloudy days.②Transpiration: Among the four treatments,BI carried through the strongest transpiration and RI did the lowest one,in sunny days RI subjected to midday depression and in cloudy days its transpiration rate fitted a single peak curve as the other treatments in sunny days.③Canopy temperature: BI抯 transpiration is strongest and RI is the weakest,as a result,BI catches the lowest canopy temperature and RI does the highest.The diversity between CI and NI is minor.The diurnal change of temperature discrepancy between each treatment is higher at noon than that of in the morning and afternoon.In the noon,canopy temperature of BI is 3 ℃ lower than that of RI.