Phenology, gas exchange, biomass accumulation, and irrigated rice yield under alternative irrigation managements

In Brazil, rice production is predominantly concentrated in the South region, employing a continuous flood irrigation system throughout the crop cycle. However, this irrigation management strategy in the tropical region contributes to low water-use efficiency owing to adverse climatic conditions. Furthermore, with climate change projections indicating reduced water availability, the study aims to investigate the impact of alternative irrigation management strategies on the phenological development, gas exchange, biomass accumulation, and productivity of tropical irrigated rice. Three alternative irrigation management approaches-intermittent flood irrigation with aeration (IFA), intermittent flood irrigation throughout the growth cycle (IFC), and intermittent flooding up to the flowering stage (IFF)-were compared with the traditional continuous flood irrigation throughout the growth cycle. Phenological data, gas exchange, growth, and productivity dynamics were subject to analysis, providing overarching insights into management practices. Notably, irrigation management exhibited no influence on the vegetative phase of the crop. The implementation of intermittent flood irrigation facilitated a reduction in water supply without compromising the physiological performance of tropical irrigated rice. Strategies promoting judicious water utilization, such as IFA and IFC, can be readily integrated into the cultivation of tropical irrigated rice without detriment to grain yield or harvest index. Intermittent flood irrigation does not compromise the physiology of tropical irrigated rice.Irrigation management does not affect the vegetative development of tropical irrigated rice.Strategies that rationalize water use do not compromise grain yield and harvest index.