Comparison of comprehensive performance of kiwifruit production in China, Iran, and Italy based on emergy and carbon emissions

Abstract

Extensive kiwifruit farming patterns worldwide are generating increasing environmental stress and thus hindering their sustainability. Comprehensive performance, based on resource efficiency and resource structure, pollutant emissions’ impact and carbon emission, is still not clear for this planting system. Therefore, this study proposes a comprehensive evaluation of kiwifruit planting systems by combining emergy analysis with carbon emission accounting method. The proposed approach not only considers the resource efficiency and resource structure of this planting system, as well as its carbon emission intensity, but also describe tradeoffs among emergy sustainability, pollutant emissions’ impacts and carbon emission intensity using the proposed index - Co-benefit index (CBI). Finally, four kiwifruit planting systems from China (Kiwifruit planting system in Sichuan province (SCPS) and Kiwifruit planting system in Shaanxi (SXPS)), Italy (Kiwifruit planting system in Italy (ITPS)) and Iran (Kiwifruit planting system in Iran (IRPS)), as case studies, are investigated using the presented approach. The study results show that (1) carbon emission intensity (CO2-eq/kg product) embodies trends of SXPS (0.16) > ITPS (0.15) > SCPS (0.12) > IRPS (0.11); (2) pollutant emissions’ impact intensity follows the trends of SXPS (2.54E+14) > ITPS (1.58E+14) > SCPS (8.29E+13) > IRPS (2.56E+13) in units of sej/t product; (3) environmental sustainability reveals trends of IRPS > ITPS > SXPS > SCPS mainly due to different environmental load rates. Generally, the four systems are not sustainable in the long term due to their high dependence on nonrenewable resources (especially labor and services (L&S) and chemical fertilizers); (4) results of Co-benefit index reflect the trends of IRPS > SCPS > ITPS > SXPS accordingly. Some targeted measures are proposed for SCPS, SXPS and ITPS. Considering low sustainability level, it is urgent for the four kiwifruit planting systems to further improve their utilization rate of chemical fertilizer and resource structure in the future.