Energy optimization and greenhouse gas emissions mitigation for agricultural and horticultural systems in Northern Iran

Highlights: • Energy and GHG of agricultural and horticultural crops surveyed comprehensively. • On-Farm and Off-Farm emissions are considered in GHG analysis. • Total energy consumption is optimized by about 20% via DEA method. • GHG reduction related to energy optimization is computed to be about 20%. • Kiwifruit is determined as energy-environmental friendly crop by DEA optimization. -- Abstract: The objective of this study is to comprehensively optimize energy usage and determine mitigation of greenhouse gas (GHG) emissions in agricultural and horticultural crops of Guilan Province, Iran. For this purpose, required data are collected from eggplant, garlic, tea, hazelnut, kiwifruit and tangerine producers through questionnaires. In this study, GHG emissions are investigated under both On-Farm and Off-Farm sectors. Data envelopment analysis method is employed for the optimization of GHG emissions and energy flow. The highest and lowest energy consumption are related to tea and kiwifruit production, respectively. Results show that kiwifruit and eggplant have the highest scores in technical efficiency whilst tangerine and tea have the highest values in pure technical efficiency. The largest amount of energy is saved in kiwifruit orchards with 8316.29 MJ ha⁻¹. Nitrogen fertilizer and diesel fuel have the topmost energy saving potential in most crops. Kiwifruit orchards have the highest potential for mitigation of GHG gas emissions (520.79 kg CO_{2 eq}. ha⁻¹). Results show that an appropriate usage of nitrogen fertilizer and replacement by organic fertilizer will mitigate GHG emissions as well as energy consumption. It can be concluded that GHG emissions can be mitigated by energy optimization in all the studied crops.