Document Type : Research Paper
Authors
1
Ph.D. candidate, Department of Mechanical Biosystems, Faculty of Agriculture, Urmia University, Urmia, Iran
2
Professor, Department of Mechanical Biosystems, Faculty of Agriculture, Urmia University, Urmia, Iran
3
Assistant Professor, Department of Mechanical Biosystems, Faculty of Agriculture, Urmia University, Urmia, Iran
Abstract
Introduction:
Sustainable agricultural production depends on the efficient management of energy inputs and the mitigation of environmental impacts through all stages of the production cycle. Evaluating energy and environmental indicators has become a fundamental method for assessing the sustainability of agricultural systems by identifying inefficiencies and potential areas for improvement. West Azerbaijan Province, located in northwestern Iran, is one of the country’s major apple-producing regions, with extensive orchard areas and a long history of horticultural cultivation. Despite its economic importance, there has been no comprehensive study addressing the energy consumption patterns and environmental emissions associated with both apple production and post-harvest storage. Apple represents a cornerstone of the local agricultural economy, providing income and employment for thousands of farmers. However, the sector’s growing dependence on fossil fuels and the intensive use of synthetic fertilizers and pesticides have raised serious environmental problems. These practices contribute to soil degradation, water contamination, and greenhouse gas emissions, ultimately threatening the long-term sustainability of apple farming. Therefore, understanding the energy flow, identifying hotspots of environmental impact, and quantifying emissions across the production and storage stages are needed. Such concepts can guide policymakers and producers toward implementing energy-efficient technologies, renewable energy integration, and eco-friendly management strategies to enhance sustainability in the apple production sector.
Material and Methods:
The research was conducted in the apple orchards of West Azerbaijan Province, located at an elevation of 1,332 meters above sea level. Data were collected from a sample of literate farmers and cold storage operators through 50 questionnaires and field observations. The collected data included information related to fuel, fertilizers, pesticides, irrigation water, machinery, labour, and storage operations. The total energy inputs were calculated using standard energy coefficients. Environmental emissions associated with fertilizer and pesticide use were quantified using accepted emission factors. The life cycle assessment (LCA) was performed using the CML methodology in SimaPro 9.5, with the Ecoinvent v3.5 database. The system boundary encompassed the processes from apple cultivation in the orchard to storage. The study focused on environmental impact categories, including global warming potential, acidification, eutrophication, human toxicity, freshwater and marine aquatic eco-toxicity, terrestrial eco-toxicity, and photochemical oxidation. Energy indices such as energy use efficiency, energy productivity, and net energy were evaluated.
Results:
The findings revealed that the total average input energy for apple orchards was 116,505 MJ per hectare, with an average yield of 34,951 kilograms per hectare. In post-harvest operations, the total average input energy was 15,727 MJ per ton of stored apples. Among the inputs, fuel accounted for the largest share of total energy consumption (39%), followed by NPK fertilizers (22%) and pesticides (14%). The energy analysis showed an energy ratio of 0.72 kg MJ⁻¹, energy efficiency of 0.32 kg MJ⁻¹, specific energy of 3.33 MJ kg⁻¹, and a negative net energy value of −32,621 MJ ha⁻¹, indicating significant energy loss in the system. These results emphasize that fuel and fertilizer consumption are dominant factors influencing the overall energy balance in apple production. In terms of environmental impacts, the study showed that eutrophication potential and freshwater aquatic toxicity had the highest values, at 473 × 10⁻⁹ and 137 × 10⁻⁹, respectively. In the post-harvest stage, marine aquatic toxicity (0.0802 × 10⁻⁹) and acidification potential (0.0121 × 10⁻⁹) were the most critical categories. The high eutrophication potential shows the excessive leaching of nitrates and phosphates from fertilizers into surface and ground water, leading to oxygen depletion and threats to aquatic life. Similarly, pesticide use contributed to the categories of marine and terrestrial ecotoxicity due to its adverse effects on soil and water ecosystems. The findings indicated that fuel consumption and fertilizer use were the main contributors to global warming potential and acidification. High diesel consumption by farm tractors was a major source of carbon dioxide emissions, thus exacerbating the greenhouse effect and increasing the overall environmental footprint of apple production in the region. The energy and environmental analyses suggest that apple production in West Azerbaijan is characterized by high input intensity and relatively low energy efficiency. The excessive use of chemical fertilizers and pesticides not only increases production costs but also deteriorates soil quality and ecosystem health. In contrast, efficient management of these inputs could improve both economic and environmental performance. Implementing precision agriculture techniques, optimizing machinery operations, and adopting renewable energy systems such as solar panels for cold storage facilities can play a role in reducing non-renewable energy dependency. Furthermore, integrating organic fertilizers, compost, and biological pest control methods can help mitigate pollution while maintaining productivity. The adoption of these practices could transform apple production into a more sustainable and environmentally friendly system.
Conclusions:
The study concludes that direct emissions resulting from fuel, fertilizer, and pesticide consumption represent the main sources of environmental impact in apple production. Unbalanced fertilizer application not only fails to improve yields but also causes irreversible damage to soil structure and water quality. The categories of eutrophication and aquatic toxicity highlight the importance of nutrient management, while the contribution of fuel consumption to global warming underlines the need for energy optimization. The results show that energy use efficiency in the studied orchards is low, and the negative net energy value indicates that the current system is not sustainable. Therefore, strategies aimed at improving fuel efficiency, reducing chemical input dependence, and using renewable energy sources are essential. Installing rooftop solar panels on cold storage buildings, using high-efficiency machinery, and combining agricultural operations are practical measures to decrease overall energy consumption. Moreover, timely pruning, diversification of orchard crops, and the use of bio-based pesticides can enhance sustainability.
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