Rice farming is a dominant rural economic as well as culturally important activity in southern Thailand. Rice production in this region is constrained by bio-physical and economic factors especially high costs of production and high application rates of chemical fertilizers. In addition, the actual outputs from rice production process are not only paddy rice but also the potential negative environmental effects. The flooded condition generates methane gas emission, while the excessive use of N-fertilizers causes the emission of nitrogen gases and the leaching of nitrate. In this study, therefore, the efficiency of use of all combination inputs and efficiency of use of chemical N-fertilizers as its excessive use causes the negative externalities are focused. The objectives of this study are to investigate the existing rice production systems and to assess the technical efficiency, economic efficiency, and environmental efficiency of rice production systems, then to investigate factors affecting the technical, economic and environmental efficiency of rice production systems in southern Thailand. Two-stage DEA methodology of efficiency analysis was focused. The two-stage DEA procedure began with calculating efficiency scores from input-oriented DEA model. Then these efficiency scores were used as dependent variables in the second stage by using the Tobit regression technique.
The total of 247 rice farm household samples was randomly selected from the main rice farming area, the Songkhla Lake Basin. The empirical results showed that 17, 2, and 2 percent of the sample farms were on the technical, economic, and environmental efficiency frontiers, respectively and the average technical, economic, and environmental inefficiency were 14, 32, and 46 percent, respectively. Moreover, the common significant variables affecting the efficiency were soil type and rice variety. To improve the efficiency of rice farms, therefore, soil quality testing which help to improve soil quality and efficiency use of chemical fertilizers is urgent needed to implement while the research on new technologies: new suitable rice variety and new fertilizer products are considered as long-term policy implementation.
