Application of life cycle analysis to assess environmental sustainability of wheat cultivation in the west of Iran

Abstract Today, intensive use of energy sources leads to environmental damages such as global warming and resources depletion. Hence, this study provided energy, environmental and economic overview of wheat cultivation in Hamedan province, Iran. The initial data were collected from 75 wheat farms applying face-to-face interview technique. The prepared data related to the 2017–2018 production cycle. The energy analysis results demonstrated that the total energy consumption and output energy in wheat cultivation were 43054.63 MJ ha−1 and 117407.13 MJ ha−1, respectively. Energy productivity, energy use efficiency and net energy gain were computed as 0.12 kg MJ−1, 2.73 and 74352.50 MJ ha−1, respectively. Economic analysis showed that total value and cost of wheat production were 854.86 $ ha−1 and 366.57 $ ha−1, respectively. Net return was 488.29 $ ha−1 and benefit to cost ratio computed as 2.33 in the investigated region. Wheat environmental impacts were evaluated by applying life cycle assessment methodology. Results of environmental impacts showed the largest emissions were related to marine aquatic ecotoxicity (319757.6377 kg 1,4-DB eq.), abiotic depletion (fossil fuels) (6673.1319 MJ) and global warming potential (624.2944 kg CO2 eq.). Electricity was a hotspot in abiotic depletion (fossil fuels), global warming potential, freshwater aquatic ecotoxicity, ozone layer depletion and photochemical oxidation impact categories. Cumulative exergy demand results indicated that the rates of non-renewable fossil (7088.05 MJ ha−1) for wheat farms mainly resulted from electricity and nitrogen fertilizer.