| Abstract | The aim of this study was to examine the energy consumption in organic and inorganic rice production systems in Suphanburi province, in the Central plain of Thailand. Raw data were collected from 50 rice farmers by field survey and personal interviews using questionnaire. Results indicated that the energy input of the organic rice production was 42.84 percent lower than the inorganic rice production. The organic rice production required a total energy of 4,275.40 MJ/ha whereas, the inorganic rice production required a total energy of 10,685.31 MJ/ha. In the inorganic rice production, energy consumption of the fertilizer application was 4,561.26 MJ/ha or 42.69 percent- which was accounted as the highest among other energy requirements in the production, followed by the energy consumption of the machinery (2,793.77 MJ/ha or 26.15 percent), seed distribution (2,569.10 MJ/ha or 24.04 percent), pesticide and herbicide application (677.37 MJ/ha or 6.34 percent) and human labor (83.81 MJ/ha or 0.78 percent). On the other hand, in the organic rice production, the energy required to distribute seeds was 2,336.82 MJ/ha or 54.66 percent which was accounted as the highest, followed by energy required by the machinery (1,769.90 MJ/ha 41.40 percent), human labor (101.64 MJ/ha 2.38 percent) and fertilizer application (67.04 MJ/ha or 1.57 percent). The highest average operational energy consumption occurred in planting, followed by tillage, harvesting, spraying and fertilizing in the organic rice production whereas, in the inorganic production, the highest energy consumption occurred in fertilizing, followed by planting, tillage, spraying and harvesting. The calculated energy ratio (output energy to input energy) and energy productivity (yield to input energy, denoted by kg/MJ) were 17.77 and 3.26 kg/MJ for the organic rice production and 7.98 and 1.67 kg/MJ for the inorganic production, respectively. Therefore, it can be stated that the organic rice production would be more efficient in terms of energy usage and energy ratio. Moreover, the cost of production remained lower on the organic rice production than the inorganic rice production. |