A COMPARATIVE WATER FOOTPRINT ANALYSIS OF ALTERNATE WETTING AND DRYING VS. CONVENTIONAL FLOODING IN RICE CULTIVATION

Water scarcity poses a major threat to rice production, limiting irrigation expansion. To address this, an experiment was conducted at the Hembeti-Dihombo irrigation scheme in Tanzania to compare alternate wetting and drying (AWD) with continuous flooding (CF) in reducing the water footprint (WF) while maximising yield. The study used the SARO Malolo rice variety over two growing seasons (July–September and September–November 2023), with a randomised complete block design and three replications for each treatment forming 6 experimental plots. Each plot measured 1 m² and was separated by a 1 m buffer zone for lateral water movement prevention. The plant spacing was set at 400 cm2, accommodating 25 plants per square meter. Several growth parameters (plant height, canopy cover, the numbers of tillers, productive tillers, panicles and grains) and water usage were monitored with data collected on a daily and weekly basis. Results showed that AWD had a significantly lower average consumptive WF (0.1887 m³/kg) than CF (0.3457 m³/kg), achieving a 65.8% water savings without compromising yield. Statistical analysis confirmed the significance (p < 0.05) of the difference. The findings suggest that AWD is a more efficient irrigation method and should be promoted through policy support to improve water use efficiency in rice farming.