A comparative study on energy use and cost analysis of potato production under different farming technologies in Hamadan province of Iran

The aim of this study was to determine the amount of input–output energy used in potato production and to make an economic analysis of potato production in Hamadan province, Iran. Data for the production of potatoes were collected from 100 producers by using a face to face questionnaire method. The population investigated was divided into two groups. Group I was consisted of 68 farmers (owner of machinery and high level of farming technology) and Group II of 32 farmers (non-owner of machinery and low level of farming technology). The results revealed that 153071.40 MJ ha⁻¹ energy consumed by Group I and 157151.12 MJ ha⁻¹ energy consumed by Group II. The energy ratio, energy productivity, specific energy, net energy gain and energy intensiveness were calculated. The net energy of potato production in Group I and Group II was 4110.95 MJ ha⁻¹ and −21744.67 MJ ha⁻¹, respectively. Cost analysis showed that total cost of potato production in Groups I and II were 4784.68 and 4172.64 $ ha⁻¹, respectively. The corresponding, benefit to cost ratio from potato production in the surveyed groups were 1.09 and 0.96, respectively. It was concluded that extension activities are needed to improve the efficiency of energy consumption in potato production.     

Study on energy efficiency in corn production of Iran

The aims of this study are determining the energy use, qualitative analyzing of energy flow and also investigating energy efficiency by Data Envelopment Analysis (DEA) in corn production of Iran during a seven years period. Results indicated that the average of total energy input increased from 40.98 GJ ha⁻¹ in 2001 to 63.64 GJ ha⁻¹ in the year of 2007. Similarly, the average of total output energy rose from 89.03 to 107.54 GJ ha⁻¹ in the same years, respectively. Also the results showed that average energy use efficiency, energy productivity, specific energy and net energy gain in the studied period was 2.59, 0.17 kg MJ⁻¹, 7.24 MJ kg⁻¹ and 51.34 GJ ha⁻¹, respectively. DEA considered the yield (kg ha⁻¹) as output and three major energy inputs; fertilizers, diesel fuel and machinery as input of 10 provinces in each year. Findings revealed that average energy efficiency score was 90.26%. There is impermanent trend in growth of energy efficiency in corn production of Iran, which needed to further analysis in future studies to realize relevant fluctuations in corn farming.     

Optimization of energy consumption for soybean production using Data Envelopment Analysis (DEA) approach

In this study a non-parametric method of Data Envelopment Analysis (DEA) is used to estimate the energy efficiencies of soybean producers based on eight energy inputs including human labor, diesel fuel, machinery, fertilizers, chemicals, water for irrigation, electricity and seed energy and single output of grain yield. The study also helps to rank efficient and inefficient farmers and to identify optimal energy requirement and wasteful uses of energy. Data were collected using face-to-face surveys from 94 farms in Golestan province which is the most important center of soybean production in Iran. Based on the results, average yield and energy consumption for soybean production were 3233.15 kg ha⁻¹ and 35372.23 MJ ha⁻¹, respectively. Also, the results of DEA application showed that, the technical, pure technical and scale efficiencies of farmers were 0.853, 0.919 and 0.926, respectively. Moreover, energy saving target ratio for soybean production was calculated as 20.12%, indicating that by following the recommendations resulted from this study, about 7116.84 MJ ha⁻¹ of total input energy could be saved while holding the constant level of soybean yield. Also, electrical energy had the highest share (78.08%) from total saving energy, followed by fertilizers (10.46%) and diesel fuel (6.18%) energy inputs.     

Energy use patterns and econometric models of major greenhouse vegetable productions in Iran

This paper examines the energy use patterns and energy input-output 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⁻¹ for cucumber and tomato productions, respectively. Among input energy sources, diesel fuel and fertilizers contained highest energy with 54.17-49.02% and 21.64-24.01%, 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 −5.87 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⁻¹ for cucumber and tomato, respectively. The benefit-cost 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.     

Modeling and sensitivity analysis of energy inputs for apple production in Iran

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 42819.25 MJ ha⁻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, 0.49 kg MJ⁻¹, 2.06 MJ kg⁻¹ and 7038.18 MJ ha⁻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.     

Optimization of energy consumption and input costs for apple production in Iran using data envelopment analysis

In this study a non-parametric method of data envelopment analysis (DEA) was applied to analyze the efficiency of farmers, discriminate efficient farmers from inefficient ones and to identify wasteful uses of energy in order to optimize the energy inputs for apple production in Tehran province, Iran. From this study the following results were obtained: from the total of 56 farmers, considered for the analysis, 34% and 54% were found to be technically and pure technically efficient, respectively. The technical, pure technical and scale efficiency scores of farmers were 0.7857, 0.8982 and 0.8666, respectively. Optimum energy requirement was found to be 37993.15 MJ ha⁻¹; indicating that 11.29% of total energy input could be saved if the recommendations of this study are followed. From total energy saving, the contribution of electrical energy was the highest; it followed by chemicals energy inputs; implying that there was a great scope for saving energy inputs by improving the use pattern of these inputs. The results of economical analysis showed that the total costs of production could decreased from 8227.70 to 7570.01 $ ha⁻¹; also the benefit to cost ratio and productivity improved from 1.24 to 1.34 and 2.52 to 2.74, respectively.     

Energy inputs – yield relationship and cost analysis of kiwifruit production in Iran

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 30285.62 MJ ha^?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 (4.05 kg $^?1) was obtained by dividing kiwifruit yield by total production cost.     

Nutrient and alkalinity removal by corn grain, stover and cob harvest in Upper Midwest USA

In the USA, most corn stover currently remains in fields as crop residue that provides soil erosion control and maintains soil organic carbon levels. This stover is a potential biofuel feedstock for direct combustion, pyrolysis, and ethanol fermentation. At a research site in south central Wisconsin, the northern edge of the US Corn Belt, corn grain harvest averaged 9.8 Mg ha⁻¹ DM over a 6-year period, 1997 to 2002. Removal of all stover could recover an additional 7.2 Mg ha⁻¹ y⁻¹ DM and, in the process, remove an additional 47, 6, 81 and 197 kg ha⁻¹ y⁻¹ of N, P, K and calcium carbonate equivalent, respectively. The fertilizer replacement cost for stover removal is 32 $ Mg⁻¹ DM, which is 95% of the fertilizer value of the grain. However, most of the N, P, K and alkalinity of the stover is found in the leaves, stalk, and husks, not in the cob. At our study site, complete stover removal would export 235 $ ha⁻¹ y⁻¹ of fertilizer and limestone, mainly as K, while cob export would be worth 20 $ ha⁻¹ y⁻¹ in nutrient equivalents. Based on this research, removal of cobs only is equivalent to 16.6% of total stover removal but with a greatly reduced fertilizer replacement cost of 17 $ Mg⁻¹ DM and the same energy density.     

Energy use pattern and sensitivity analysis of energy inputs and input costs for pear production in Iran

The purposes of this study were to determine energy use pattern and investigate the relationships between energy inputs and yield, cost inputs and income for pear production in the Tehran province of Iran. In this study, data were collected by administering a questionnaire in face-to-face interviews in the production year of 2009/2010. This article presents a comprehensive picture of the current status of energy consumption and some energy indices like energy ratio, energy productivity, specific energy, net energy and energy intensiveness. Results showed that the total energy input of 172,608.43 MJ ha⁻¹ was required for pear production. Among input energy sources, electricity energy with share of 78% of total input energy had the highest share. The energy use efficiency and energy productivity were found as 0.51 and 0.27 kg MJ⁻¹, respectively. To investigate the relationships between energy inputs and yield, cost inputs and income, Cobb–Douglas production function was selected as the best function. Sensitivity analysis of energy and cost inputs was carried out using the marginal physical productivity (MPP) technique. Economic analysis of pear production was carried out and total cost of pear production was obtained as 11,936.97 $ h⁻¹. Also the benefit to cost ratio was calculated as 3.11.     

Economical analysis and relation between energy inputs and yield of greenhouse cucumber production in Iran

This paper studies the energy balance between the input and the output per unit area for greenhouse cucumber production. For this purpose, the data on 43 cucumber production greenhouses in the Tehran province, Iran, were collected and analyzed. The results indicated that a total energy input of 148836.76 MJ ha⁻¹ was consumed for cucumber production. Diesel fuel (with 41.94%) and chemical fertilizers (with 19.69%) were amongst the highest energy inputs for cucumber production. The energy productivity was estimated as 0.80 kg MJ⁻¹. The ratio of energy output to energy input was approximately 0.64. Results indicate 10.93% and 89.07% of total energy input was in renewable and non-renewable forms, respectively. The regression results revealed that the contribution of energy inputs on crop yield (except for fertilizers and seeds energies) was significant. The human labour energy had the highest impact (0.35) among the other inputs in greenhouse cucumber production. Econometric analysis indicated that the total cost of production for one hectare of cucumber production was around 33425.70 $. Accordingly, the benefit–cost ratio was estimated as 2.58.     

Biomass and energy yield of industrial hemp grown for biogas and solid fuel

This study examined the energy yield of hemp (Cannabis sativa L.) cultivated for energy purposes under cold climate conditions in Northern Europe. Split-plot field trials were carried out over three consecutive years to investigate different nitrogen fertilisation regimes. Dry matter yield per hectare, moisture content, hydrogen content and heating value were determined at roughly monthly intervals from July until the following spring every season. The energy yield was calculated and adjusted for a fair comparison with those of other energy crops commonly grown in the study region.Two harvest periods for optimal energy yield have been determined; harvest in September to October, when the hemp is used for biogas production, yielded 14.4 Mg ha⁻¹ and 296 GJ ha⁻¹; harvest in February to April, when the hemp is used as a solid fuel, yielded 9.9 Mg ha⁻¹ and 246 GJ ha⁻¹. For biogas production, the adjusted biomass energy yield of hemp was similar to that of maize and sugar beet and 24 and 14% greater than that of lucerne and clover-grass ley, respectively. As a solid fuel, the adjusted biomass energy yield of hemp was 120% higher than that of wheat straw and similar to that of reed canary grass. Annual variations in dry matter yield depending on weather conditions and sowing dates exceeded variations due to nitrogen fertilisation.Hemp is suitable as an energy crop in cold climate regions of Northern Europe, as it has similar or often higher energy yields than other common energy crops grown in these regions.     

On-farm energetics of mango production in Nigeria

The aims of this study were to determine direct input energy, indirect energy and other energy use indices in mango production in a group of mango plantation of a research farm in Nigeria. The study also estimated the economic indices of mango production in the study area and energy potentials of mango by-products. The average energy consumption of the plantations investigated in this study is 15,015.16 MJ ha⁻¹. Out of the total energy, 93% was direct and 7% was indirect. Renewable energy accounted for 21% and energy usage efficiency was found to be 1.3. The total energy input into the production of 1 kg of mango was estimated to be 0.70 MJ. The dominant contribution to input was energy in the form of diesel used in tractor operation and captive power generation (56%), followed by human labor used for land preparation, cultural practices and harvesting (33%), machinery (5%) and chemicals, mainly herbicides (4%). The use of energetically available residues of mango could give an average value addition of 57,067 MJ/ha. The cost of mango production per hectare was found to be 2246 $ ha⁻¹. As a result of benefit-cost ratio value (1.24), energy use efficiency and the energy value addition from mango residues, mango production was found to be economically efficient in the study area.     

An investigation on energy consumption and sensitivity analysis of soybean production farms

The aims of this study were to determine the energy consumption and evaluation of inputs sensitivity for soybean production in Kordkuy county of Iran. The data used in this study were obtained from 32 farmers using a face-to-face questionnaire base of random sampling method. The sensitivity of energy inputs was estimated using the marginal physical productivity (MPP) method and partial regression coefficients on soybean yield. The results indicated that the total input and output energy use was to be 18,026.50 and 71,228.86 MJ ha⁻¹ respectively. With 66.67%, the diesel fuel was the highest within the energy equivalents and followed by chemical fertilizers and water for irrigation with 14.32% and 6.18% respectively. The input-output ratio was found as 4.62 (used efficiency). The share of direct, indirect, renewable and non-renewable was 74%, 26%, 14% and 86% respectively. The econometric model estimation emphasized that the seed was significantly positive on yield. The sensitivity analysis indicated the MPP value of 2.42 for seed, indicates that with an additional use of 1 MJ of seed energy would lead to an increase in yield by 2.42. The impact of direct, indirect and non-renewable energies on yield was significant.     

Comparison of energy inputs in glasshouse double crop (fall and summer crops) tomato production

The study examines energy use patterns and the relationship between energy inputs and yield for double crop (fall and summer) glasshouse tomato production in Antalya province, where is one of the most important greenhouse centres in Turkey. The data of the study was retrieved from 37 fall and 25 summer glasshouse tomato producers via face to face survey in 2007. The research findings revealed energy use values for inputs such as manure, electricity, chemical fertilizer and fuel. While the average yield per hectare is 25025.4 kg for enterprises involved in tomato production in fall, it is 22392.9 kg for summer production. The overall energy consumption is higher in fall production with 81362.2 MJ ha^?1 in comparison to summer production 63023.2 MJ ha^?1. In addition, the specific energy requirement is 3521.2 MJ t^?1 and 2814.4 MJ t^?1 for fall and summer production in order and the energy efficiency was found out to be 0.31 kg MJ^?1 and 0.36 kg MJ^?1 respectively. Finally, the energy relationship was tested using the production relationship. The findings indicated that direct energy sources are effective in tomato yield for both of the two seasons. More clearly, the most significant energy input was electrical energy for summer production and a combination of electrical energy, human power and machinery for fall production. Yet, excess and unconscious use of chemical ingredients in glasshouse tomato production was confirmed as energy derived from chemical drugs leaded a declination in the yield for fall season. Therefore, the paper revealed energy relationship for double crop glasshouse tomato production in Antalya, being a reference for similar production methodologies.     

Impact of miscanthus yield on harvesting cost and fuel consumption

Miscanthus is emerging as a potential bioenergy crop because of its high yield and ability to reduce greenhouse gas emissions. However, there is a lack of data on harvesting machinery performance for the USA conditions, and influence of yield on harvesting cost and fuel consumption. This study quantified performance of a mower-conditioner and a large square baler for Illinois conditions, and investigated influence of yield on fuel consumption and harvesting costs. To calculate performance parameters, a field area was segmented from which a bale was formed. Then in the segmented field area, yield and machine performance parameters were determined. The mower-conditioner's field capacity was 1.8 ha h⁻¹, and diesel consumption was 19.2 L ha⁻¹. The baler's field capacity was 1.4 ha h⁻¹, and diesel consumption was 19.7 L ha⁻¹. The mowing cost was 4.8 $ Mg⁻¹, and baling cost was 6.8 $ Mg⁻¹. An inverse correlation (R² = 0.62) was found between miscanthus yield and harvesting cost ($ Mg⁻¹), and a direct correlation (R² = 0.67) was found between miscanthus yield and fuel consumption (L ha⁻¹). It is expected that this study would help in more accurate assessment of environmental impact and economic feasibility of miscanthus, and may lead to further studies for quantifying crop yield and machine performance interactions.     

Techno-economic comparisons of hydrogen and synthetic fuel production using forest residue feedstock

Mobile distributed pyrolysis facilities have been proposed for delivery of a forest residue resource to bio-fuel facilities. This study examines the costs of producing hydrogen or synthetic petrol (gasoline) and diesel from feedstock produced by mobile facilities (bio-oil, bio-slurry, torrefied wood). Results show that using these feedstock can provide fuels at costs competitive to conventional bio-fuel production methods using gasification of a woodchip feedstock. Using a bio-oil feedstock in combination with bio-oil steam reforming or bio-oil upgrading can produce hydrogen or petrol and diesel at costs of 3.25 $ kg⁻¹ or 0.86 $ litre⁻¹, respectively, for optimally sized bio-fuel facilities. When compared on an energy basis ($ GJ⁻¹), hydrogen production costs tend to be lower than those for synthetic petrol or diesel production across a variety of bio-fuel production pathways.     

Fuel cells for automotive powertrains—A techno-economic assessment

With the objective of identifying the hurdles currently preventing a widespread application of fuel cell technology in passenger cars an assessment of technical and economic parameters is carried out. Patent and publication analysis is used to assess current status of fuel cell technology regarding its position on technology life cycle. S-curve methodology leads to the conclusion that further scientific activity is to be expected but for today's low-temperature PEM fuel cell technology might level by 2015. Technical analysis identifies power density and platinum loading as parameters for which further improvements are necessary in order to satisfy future customer needs. A detailed cost evaluation suggests that in future for high production volumes (approx. 1 million vehicles cumulative) significantly lower costs for fuel cell stacks (12–40$ kW⁻¹) and systems (35–83$ kW⁻¹) will be viable. Reducing costs to such a level will have to be the main focus for upcoming research activities in order to make fuel cell driven road vehicles a competitive alternative.     

Harvesting productivity and costs when utilizing energywood from pine plantations of the southern Coastal Plain USA

For woody biomass to make a significant contribution to the United States' energy portfolio, harvesting contractors must economically harvest and transport energywood to conversion/processing facilities. We conducted a designed operational study in the Coastal Plain of North Carolina, USA with three replications of three treatments to measure harvesting productivity and costs when utilizing woody biomass. The treatments were: a conventional roundwood only harvest (control), an integrated harvest in which merchantable roundwood was delivered to mills and residuals were chipped for energy, and a chip harvest in which all stems were chipped for energy use. The harvesting contractor in this study typically delivers 2200–2700 t of green roundwood per week and is capable of wet-site harvesting. Results indicate that onboard truck green roundwood costs increased from 9.35 $ t⁻¹ in the conventional treatment to 10.98 $ t⁻¹ in the integrated treatment as a result of reduced felling and skidding productivity. Green energy chips were produced for 19.19 $ t⁻¹ onboard truck in the integrated treatment and 17.93 $ t⁻¹ in the chip treatment. Low skidding productivity contributed to high chip costs in the integrated treatment. Residual green biomass was reduced from 18 t ha⁻¹ in the conventional treatment to 4 and 3 t ha⁻¹ in the integrated and chip treatments, respectively. This study suggests that until energywood prices appreciate substantially, loggers are unlikely to sacrifice roundwood production to increase energywood production. This research provides unique information from a designed experiment documenting how producing energywood affects each function of a harvesting system.     

An analysis of energy use and relation between energy inputs and yield,costs and income of garlic production in Iran

This paper studies the energy balance between the input and the output per unit area for garlic in Hamedan province of Iran. In this study, data were collected by administering a questionnaire in face-to-face interviews. Results showed that the highest share of energy consumption belongs to chemical fertilizers (41.7%) followed by diesel (13.94%). The results indicated that a total energy input of 40307.89 MJ ha^?1 was consumed for garlic production. The energy productivity and net energy value were estimated as 0.416 kg MJ^?1 and ?13477.82 MJ ha^?1, respectively. The ratio of energy outputs to energy inputs was approximately 0.66. Results indicated that direct, indirect, renewable and non-renewable energies were (28.14%), (71.85%), (36.73%) and (63.26%), respectively. Highest shares of expenses were found to be 45% and 19% for human labor and hired machineries, respectively. Cost analysis revealed that total cost of production for 1 ha garlic production was around 6969.11$. Accordingly, the benefit-cost ratio was estimated as 1.36. Using Cobb-Douglas model, energy function was estimated with the coefficient of determination, R² of (80%), and expenses function was estimated with coefficient of determination, R² of (83%).