Economic efficiency of rice farming under alternate wetting and drying irrigation in the Vietnamese Mekong Delta

Abstract This study assesses the economic efficiency (EE) of low-emission rice production under Alternate Wetting and Drying (AWD) irrigation in the Mekong Delta using survey data from 250 households. Descriptive statistics profile farm characteristics, practices, and costs; efficiency is estimated with non-parametric Data Envelopment Analysis (DEA), and determinants are examined via Ordinary Least Squares. Farmers adopting AWD achieved an average profit of 26.30 million VND per hectare per crop, with average costs of 21.80 million VND and an average yield of 7.14 tons/ha/crop. The cost structure is dominated by fuel and energy, fertilizer, and hired labor. Reported fertilizer use averaged 100.62 kg/ha of nitrogen, 47.84 kg/ha of phosphorus, and 53.37 kg/ha of potassium per crop—broadly consistent with prior Mekong Delta figures (e.g., N ≈ 99.6, P ≈ 46.69, K ≈ 51.8 kg/ha/crop), with phosphorus application marginally lower in some comparisons. The DEA results indicate an average EE of 48.45%, alongside technical and allocative efficiency of 69.94% and 70.44%, respectively. The regression shows that education and cultivated area are significant positive correlates of efficiency, whereas age, gender, household labor, and farming experience are not statistically significant. Overall, while AWD rice farming delivers measurable outcomes on yields and costs, average EE remains below optimal, highlighting the importance of scale and human capital for performance gains.