Energy consumption and CO2 emissions analysis of potato production based on different farm size levels in Iran

The aim of this research was to examine the energy consumption and CO2 emission of potato production in three different farm size sin Esfahan province of Iran. For this purpose, data were collected from 300 farmers by a face to face questionnaire. The results revealed total energy consumption and GHG emission of 47 GJ ha(-1) and 992.88 kg CO2eq ha(-1), respectively. The most significant energy consumer was chemical fertilizers (49%), especially nitrogen (40%) and followed by seed with share of 24%. The energy use efficiency, specific energy and energy productivity were determined to be 1.71, 2.12 MJ kg(-1) and 0.47 kg MJ(-1). The different cultivated area levels analysis revealed that, large farms used the least amount of energy input significantly. It was found that the contribution of indirect energy was higher than that of direct energy and also the proportion of non-renewable energy was more than renewable resources. The results of econometric model estimation revealed that the impact of seed, water for irrigation, diesel fuel and chemical fertilizer energy inputs were significantly positive on potato yield. The sensitivity analysis illustrated that the marginal physical productivity (MPP) value of chemical fertilizer, diesel fuel and seed energy were -1.78 and -1.63 and 1.54, respectively. (C) 2012 Elsevier Ltd. All rights reserved.