investigation of energy balance in castor bean cultivation in varamin county for biodiesel production

castor bean (ricinus communis l.( with a capability to withstand harsh conditions, low nutritional needs, 50 percent of oil content and high- quality, is one of the best crop used to produce biodiesel. the first step toward introduction and widespread cultivation of this crop is to investigate the energy balance for its cultivation. to do so, energy input (include renewable and nonrenewable) and output were calculated through an examination of all inputs during two consecutive years of cultivation (2012-2014) in varamin county in tehran province. energy indicators were also assessed. result showed indirect, non-renewable sources of energy with 59.68 and 80.86 percent of 11245.64 mj energy consumption, comprise the major part of the consumable energy in castor bean cultivation. moreover, among inputs fertilizers and pesticides with the share of 55.26 percent of the total consumable energy considered as the highest energy inputs. fuels with the share of 21.28 percent formed placed at the second rank of consumable energy. energy use efficiency in seed production was calculated to be 3.81, which is a considerable amount when compared with other crops used to produce biodiesel. therefore, in order to expand the cost efficient and mechanized system of castor production, breeding of the current local ecotypes is recommended.