Improving Water Use Efficiency in Paddy Fields through Controlled Deficit Irrigation

Abstract

Water scarcity poses a critical challenge to sustainable rice production, particularly in regions reliant on irrigation. This study evaluated the effects of controlled deficit irrigation strategies on the growth, yield, and water use efficiency (WUE) of rice under field conditions. Four irrigation regimes—Continuous Flooding (CF), Alternate Wetting and Drying (AWD), Saturated Soil Culture (SSC), and Regulated Deficit Irrigation (RDI)—were compared using the Super Basmati cultivar. AWD consistently outperformed other treatments by producing the tallest plants (108.7 cm), highest number of tillers per hill (12.5), maximum panicles per m² (340), and superior yield attributes such as grains per panicle (150) and 1000-grain weight (23.5 g). It also achieved the highest grain yield (6.2 t ha⁻¹), biological yield (13.8 t ha⁻¹), and WUE (0.62 kg m⁻³). In contrast, SSC resulted in the poorest performance across most parameters due to reduced oxygen availability and suboptimal root functioning. These findings indicate that AWD is a promising water-saving technique that improves rice productivity without compromising yield, making it a viable strategy for enhancing irrigation efficiency in water-limited environments.