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This study examines energy use patterns and the relationship between energy inputs and yield for soybean production in the Golestan province of Iran. Data used in this study were obtained from randomly selected soybean farms using a face-to-face survey. The results revealed that total energy of 35372.23 MJ ha-1 was required for soybean production and electricity, chemical fertilizers, and diesel fuel were the main energy consuming inputs. Energy use efficiency, energy productivity, and specific energy were 2.29, 0.09 kg MJ-1, and 10.94 MJ kg-1, respectively. Moreover, in specifying a functional relationship the Cobb-Douglas production function was selected as the best function. The results showed that fertilizer, water for irrigation, diesel fuel, machinery, human labor, and electricity energies significantly contributed to yield; while, the use of chemicals and seed energies was inconsistent with output. Also, the marginal physical productivity (MPP) technique was applied to analyze the effect of energy use on soybean production. It was found that, soybean production had more sensitivity on machinery, human labor, and water for irrigation energies; so that, an additional use of 1 MJ from each of the machinery, human labor, and water for irrigation energies would lead to increase in output by 0.57, 0.44, and 0.23 kg, respectively. [ABSTRACT FROM AUTHOR]

Abstract: This study examines energy consumption of inputs and output used in kiwifruit production, and to find relationship between energy inputs and yield in Mazandaran, Iran. For this purpose, the data were collected from 86 kiwifruit orchards which were selected based on random sampling method. The results indicated that total energy inputs were 30285.62MJha−1. About 47% of this was generated by total fertilizer including farmyard manure, 28% from diesel fuel and machinery. About 70% of the total energy inputs used in kiwifruit production was indirect while only about 30% was direct. Econometric estimation results revealed that energy inputs of human labour, water for irrigation, total fertilizer and machinery contributed significantly to the yield. The impact of human labour energy (0.17) was found the highest among the other inputs in kiwifruit production. The results also showed that direct, indirect and renewable and non-renewable, energy forms had a positive impact on output level. Cost analysis showed that total cost of kiwifruit production was obtained as 6063.81$ha−1. The productivity (4.05kg$−1) was obtained by dividing kiwifruit yield by total production cost. [Copyright &y& Elsevier]

Abstract: The objective of this study was to determine energy use efficiency in greenhouse cucumber production using a non-parametric production function. The method used to quantify energy use efficiency or, more specifically, excess input energy used, is data envelopment analysis (DEA). DEA creates a ‘‘best practice’’ production frontier based on the growers that produce their level of cucumber yield with the least amount of input energy. These greenhouses then serve as benchmarks against which the energy use inefficiency of all other growers can be measured. The data used in this study was obtained through a face-to-face questionnaire method in the surveyed region – Yazd province of Iran. The total energy input and energy output were calculated to be 1168023 and 124663MJha−1, respectively. According to this information, the energy productivity was 0.14kgMJ−1, and net energy value was estimated to be –1043360MJha−1 indicating energy has been lost in greenhouse cucumber production. Basic DEA models (CCR and BCC) were used to measure the technical efficiency of the growers based on seven energy inputs human labor, diesel fuel, FYM, fertilizers, chemicals, water for irrigation and electricity, and a single output included yield of cucumber (kgha−1). The CCR and BCC models indicated 10 and 25growers were efficient, respectively. The average values of overall technical efficiency, pure technical efficiency and scale efficiency of growers were found to be 0.8235, 0.9273 and 0.8880, respectively. The results also revealed that about 21% of the total input resources could be saved if the growers follow the input package recommended by the DEA. The maximum contribution to the total energy savings is 53% from diesel fuel, followed by electricity (27%). [Copyright &y& Elsevier]

Abstract: This study was conducted to determine the energy balance between the energy inputs and yield for apple production in Tehran, Iran. For this purpose the data were collected from 56 apple orchards. The following results were obtained from this study: The total energy input of 42819.25MJha−1 was required for apple production. The share of diesel fuel by 21.88% of the total energy inputs was the highest energy input. This was followed by farmyard manure (17.66%) and electricity (13.09%), respectively. The energy use efficiency, energy productivity, Specific energy, and net energy were found as 1.16, 0.49kgMJ−1, 2.06MJkg−1 and 7038.18MJha−1, respectively. According to the research results, the contribution of direct energy was higher than that of indirect energy; also the share of non-renewable energy was more than that of renewable energy. The results of econometric model estimation revealed that the impact of farmyard manure, water for irrigation, electricity, chemical fertilizer and human labour energy inputs were significantly positive on yield. The results of sensitivity analysis of the energy inputs showed that the MPP value of water for irrigation was the highest, followed by human labour and chemicals energy inputs, respectively. [Copyright &y& Elsevier]

Abstract: In this study energy use pattern for canola production in Golestan province of Iran was studied and the degrees of technical and scale efficiency of producers were analyzed using a non-parametric data envelopment analysis technique. The study also helped to identify the wasteful uses of energy by inefficient farmers and to suggest reasonable savings in energy uses from different inputs. Further, the effect of optimization of energy on energy ratio and energy productivity was investigated. Data used in this study were obtained from 130 randomly selected canola farms from Golestan, the most important center of canola production in Iran. The inputs were human labor, diesel, machinery, fertilizers, chemicals, water for irrigation, seeds and electrical energies; while the yield value of canola was considered as output. The results revealed that, the total energy of 17,786MJha−1 was consumed for canola production; about 15% of farmers were found to be technically efficient and the mean efficiency of farmers was found to be 0.74 and 0.88 under constant and variable returns to scale assumptions, respectively. The results also suggested that, on average, a potential 9.5% (1696MJha−1) reduction in total energy input could be achieved provided that all farmers operated efficiently. [Copyright &y& Elsevier]