Energy use patterns and econometric models of major greenhouse vegetable productions in Iran M.D. Heidari, M. Omid * Department of Agricultural Mechanization Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran article info Article history: Received 6 July 2010 Received in revised form 7 October 2010 Accepted 25 October 2010 Available online xxx Keywords: Greenhouse crops Energy use patterns Energy inputeoutput analysis Energy forms Sensitivity analysis Benefitecost ratio abstract This paper examines the energy use patterns and energy inputeoutput analysis of major greenhouse vegetable productions in Iran. Data from 43 farmers were obtained using a face-to-face questionnaire method. The majority of farmers in the surveyed region were growing cucumber and tomato. Total input energy was found to be 141493.51 and 131634.19 MJ ha À1 for cucumber and tomato productions, respectively. Among input energy sources, diesel fuel and fertilizers contained highest energy with 54.17 e49.02% and 21.64e24.01%, respectively. The energy ratio was found to be 0.69 and 1.48 for cucumber and tomato productions, respectively. Econometric model evaluation showed the impact of human labor for cucumber and chemicals for tomato was significant at 1% levels. Sensitivity analysis indicated that the MPP value of energy inputs were between À5.87 and 7.74. RTS (returns to scale) values for cucumber and tomato yields were found to be 1.29 and 0.76; thus, there prevailed an IRS of cucumber for estimated model. The net return was found positive, as 22651.13 and 78125.08 $ ha À1 for cucumber and tomato, respectively. The benefitecost ratios from cucumber and tomato productions were calculated to be 1.68 and 3.28, respectively. Among the surveyed greenhouses, the result indicated tomato cultivation was more profitable. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Greenhouse production is one of the most intensive parts of the world agricultural production. It is intensive in the sense of yield and annual production, but also in sense of the energy consumption, investments and costs [1]. Greenhouses use large quantities of locally available non-commercial energies, such as manure, animate and seed energies and commercial energies directly and indirectly in the form of diesel, electricity, fertilizer, pesticides, irrigation water, machinery, etc. [2]. Efficient use of these energies helps to achieve increased productivity and contributes to the economy, profitability and competitiveness of agricultural sustainability of rural communities [3e7]. Agriculture has the potential to become an increasingly impor- tant source of renewable energy and provide significant economic opportunities for farmers and ranchers. Energy usage, forms of energies, and inputeoutput relationships in cropping systems vary with crops being grown in sequence, by type of soils, nature of tillage operations for seedbed preparation, nature and amount of chemical fertilizer, plant protection measures, harvesting and threshing operations and, finally, yield levels [2]. Some researchers have conducted generally on worldwide production of greenhouse crops. Onal et al. [5] analyzed the work efficiency and energy consumption of alternative production systems for producing tomatoes. As a result of these analyses, the most suitable system, which resulted in the highest yield with the lowest energy consumption, was determined. Although many experimental works have been conducted on energy use in agriculture, there are few studies on the energy use pattern of greenhouse crops production [4,6e9]. In [4], [6] and [9] energy use for greenhouse vegetables (tomato, cucumber, eggplant and pepper) production in Turkey were investigated, but the authors were not concerned with the functional relationship between energy inputs and yield. It is realized that crop yields and food supplies are directly linked to energy [10]. In the developed countries, an increase in the crop yield was mainly due to an increase in the commercial energy inputs in addition to improved crop varieties. Generally, land productivity is measured as the total measure of crop productivity. In a number of recent research papers, the yield that is the amount of crop produced per unit area (kg ha À1 ), has been considered as the total measure of productivity [11]. However, it is only a partial measure of agricultural productivity like other measures, such as * Corresponding author. Tel.: þ98 261 2801011; fax: þ98 261 2808138. E-mail address: omid@ut.ac.ir (M. Omid). Contents lists available at ScienceDirect Energy journal homepage: www.elsevier.com/locate/energy 0360-5442/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.energy.2010.10.048 Energy xxx (2010) 1e6 Please cite this article in press as: Heidari MD, Omid M, Energy use patterns and econometric models of major greenhouse vegetable productions in Iran, Energy (2010), doi:10.1016/j.energy.2010.10.048