An Investigation of the Environmental Impacts and Energy-Economic Analysis for Sugar Beet and Sugarcane Production Systems

This study evaluates energy indicators, productivity, economic justification and environmental emissions of sugar beet and sugarcane cultivation in Khuzestan province, Iran. The results showed that the total energy consumption in sugar beet and sugarcane production was 58,487.80 MJ ha−1 and 61,220.62 MJ ha−1, respectively. The highest energy costs are spent on chemical fertilizers (35.47% for sugarcane), electricity (23.62% for sugar beet) and water (22.45% for sugar beet), respectively. Of the total energy consumption, 77.39% and 83.69% were non-renewable energy for sugar beet and sugarcane, respectively. Of this amount, 59.42% was consumed directly for sugar beet and 58.94% for sugarcane. Benefit-to-cost ratio was calculated in sugarcane (2.77) and in sugar beet (1.05) fields, and production productivity was calculated in sugarcane (25.22 kg $−1) and in sugar beet (9.15 kg $−1) fields. Life cycle assessment (LCA) approach was used based on the ISO 14040 standard. CML-IA baseline method was applied for impact assessment. The results of environmental impacts show that sugarcane has more On-Farm emissions than sugar beet. Carbon dioxide (CO2) released by human labor in the cultivation of sugarcane in the air causes the release of 3.7 times more than sugar beet fields. The total emissions from diesel fuel to the air for sugar beet and sugarcane cultivation are 745.79 kg ha−1 and 849.99 kg ha−1, respectively. According to the results, sugarcane cultivation is more economical than sugar beet cultivation in all respects, but it has a higher water consumption, which can be controlled by proper irrigation management practices. It is suggested that reduction of energy, environmental consequences and improve the economic performance of sugarcane and sugar beet life cycle can be reduced by optimization of chemicals uses such as chemical fertilizers and pesticides in the farm, using renewable energy such as photovoltaic cells or wind turbines instead of fossil fuels for water pumping.