Energy and economic assessment of prune production in Tehran province of Iran Seyed Mohammad Hossein Tabatabaie * , Shahin Rafiee, Alireza Keyhani, Amirhossein Ebrahimi Department of Agricultural Machinery Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran article info Article history: Received 21 April 2012 Received in revised form 25 July 2012 Accepted 27 July 2012 Available online 13 August 2012 Keywords: CobbeDouglas Economic analysis Energy efficiency Prune Sensitivity analysis abstract This study examines energy use patterns and the relationship between energy inputs and yield for prune production in the Tehran province of Iran. In this study, data were collected by administering a ques- tionnaire in face-to-face interviews. This article presents a comprehensive picture of the current status of energy consumption and some energy indices such as energy ratio, energy productivity, specific energy, net energy and energy intensiveness. Also the distribution of total energy input as direct, indirect, renewable and non-renewable forms was analyzed. The CobbeDouglas production function was used to estimate an econometric model for energy inputs, and the marginal physical productivity technique was applied to analyze the sensitivity of energy inputs. Economic analysis of prune production was carried out, and some economic indicators such as total cost of production, total production value, gross return, net return, benefit-to-cost ratio and productivity were computed. This study suggests some ways to improve energy efficiency such as changing irrigation method, applying conservation agriculture and optimization of energy use. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Since prunes (Prunus salicina) are rich in fiber and antioxidants, they can contribute to human nutrition (Crisosto and Day, 2012). In 2009 the world production of plums and sloes was about 10.7 Mt from 2.5 Mha (FAO, 2011). China produces the most plums and sloes, and Spain, China, USA and Netherlands are important plum and sloe exporting countries. In 2008, Iran produced almost 191,000 t of plums and sloes (FAO, 2011). Considering the energy balance of crop production was much debated in the early 1970s when the world energy crisis made people aware that the supply of fossil energy is limited (Pimentel et al., 1973). Some factors such as population increase, limited supply of arable land and desire for an increasing standard of living have caused energy use to increase. Accordingly, to maximize yields and minimize labor, energy inputs have increased (Karimi et al., 2008). To evaluate the sustainability of agriculture per se, its energy efficiency must be considered, and major sources of energy waste must be identified and assessed (Pervanchona et al., 2002). The energy inputeoutput analyses are usually performed to measure the energy efficiency and environmental aspects (Rafiee et al., 2010). A pillar for sustainable development is integrating technology into environmentally-friendly production systems. Studies have shown the agro-food sector to be one of the largest contributors to environmental impacts, via resource depletion, land degradation, gaseous emissions and waste generation (Cellura et al., 2012). To manage a rising energy-consumption rate, deple- tion of natural resources and environmental degradation, energy efficiency should be improved (Dovì et al., 2009). Several experiments have been conducted on energy use of agricultural crops such as kiwifruit in Iran (Mohammadi et al., 2010), oranges in Italy (La Rosa et al., 2008), cherries in Turkey (Kizilaslan, 2009), greenhouse vegetables in Turkey (Canakci and Akinci, 2006), canola in Iran (Mousavi-Avval et al., 2011) and sunflower in Chile (Iriarte et al., 2010). Studies of the energy inputeyield relationship and cost analysis for orchard products are limited, and no energy or cost analyses of prunes were found in the literature review. Thus, the aims of this study were to analyze the energy consumption and costs of fresh prune production. Also, this study aimed to develop a model of the energy inputeyield relationship in prune production in Iran. 2. Materiaxls and methods Economic and energy input data were obtained from 120 farmers using face-to-face questionnaires in Tehran province (35  42 0 N, 51  19 0 E) of Iran. In 2009, Tehran province produced the most prunes in Iran (Anonymous, 2009). The mean orchard size was 0.7 ha in the studied area (range ¼ 0.25e4 ha). Data were collected in the 2009e2010 production year. Orchards were selected using * Corresponding author. Tel.: þ98 261 2801011; fax: þ98 261 2808138. E-mail address: smh.tabatabaie@ut.ac.ir (S.M.H. Tabatabaie). Contents lists available at SciVerse ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro 0959-6526/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jclepro.2012.07.052 Journal of Cleaner Production 39 (2013) 280e284