Optimizing water footprints and yield sustainability in Boro rice through alternate wetting and intense drying: A climate-resilient strategy for Bangladesh

ABSTRACT Climate change and water scarcity pose significant challenges to rice production in Bangladesh, necessitating water-efficient practices. This study, conducted during the 2024 Boro rice season in Mymensingh, Bangladesh, compared the impacts of alternate wetting and intense drying (AWID), with irrigation at a 20-cm water level drop, against continuous flooding (CF) and alternate wetting and moderate drying (AWMD), with a 15 cm drop. The AWID resulted in 46.12% water savings and a 43.1% increase in crop–water productivity, yielding 5.10 t/ha, while AWMD saved 38.64% water with a yield of 6.13 t/ha. Despite a 22.7% yield reduction compared to CF (6.60 t/ha), AWID's superior water efficiency underscores its potential as a sustainable option in water-scarce regions. Excluding the first 15-day crop establishment phase, the water footprint was lowest for AWMD (1003.83 L/kg) and AWID (1079.68 L/kg) compared to CF (1439.00 L/kg). Climate projections for the 2040 and 2070s indicate increased temperatures, decreased rainfall, and higher evapotranspiration, potentially raising irrigation demands by up to 30% under RCP 8.5 scenarios. These water-saving techniques offer promising strategies for sustaining rice production while conserving water resources. Further research is recommended to optimize these practices across diverse agro-ecological zones, enhancing climate resilience in rice cultivation.