Evaluating the Performance of Alternate Wetting and Drying Irrigation Technology: An On-farm Rice Case Study in An Giang Province, the Mekong Delta of Vietnam

Abstract

Alternate wetting and drying irrigation (AWD) is a promising technique that has been tried across Southeast Asia to reduce water consumption and methane emissions in irrigated rice cultivation. The study conducted in the upper Vietnamese Mekong Delta compared the effectiveness of plant growth, yield components, and yield under three different water application regimes: the treatments of community AWD (AWD_C), household individually (AWD_H), and continuous flooding (CF) with the expectation to explore the ability to use water effectively in rice cultivation. The results showed no significant difference in water use between the three treatments. However, there was a considerable difference in coefficient of variation value (CV); the CV value of the water column in the AWD_C (1.32%) was a significant difference from that of AWD_H (0.87%) and CF (0.89%). The mean chlorophyll content, the yield, and the weight of 1,000 grains of the AWD_H treatment were significantly higher than that of the other two treatments. In another aspect, the water productivity of the AWD_H treatment was the highest (0.66 kg/m3), a statistically significant difference compared to the AWD_C and CF (0.37; 0.33 kg/m3). In conclusion, the AWD_H shows efficiency in leaf chlorophyll content, 1,000-grain weight, yield, and water productivity. The AWD_C is inferior to the AWD_H due to the large variation of field elevation. It is noted that field elevation is critical to the technique’s success in being applied on a large scale.