Photosynthetic and yield responses of rice (Oryza sativa L.) to different water management strategies in subtropical China

Abstract

An experiment was performed to study gas exchange and chlorophyll fluorescence responses of rice (Oryza sativa L.) to various regimes, such as flooding–midseason drying–flooding (FDF), flooding–midseason drying–saturation (FDS), and flooding–rain-fed (FR) regimes. Compared to FDF, FR resulted in an obvious decrease in net photosynthetic rate (PN), due to the decrease in stomatal conductance and the increase in stomatal limitation. In contrast, FDS plants did not suffer stomatal limitation and had comparable PN with FDF plants. For diurnal light-saturated electron transport rate and saturation irradiance, FDF performed the best, which was followed by FDS and FR successively. FR and FDS plants tended to suffer from midday depression. FDS reduced irrigated water by 17.2% compared to FDF for comparable yields. The results suggested that FDS can be an effective irrigation regime to save water.