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Energy use on organic farming: A comparative analysis on organic versus conventional apricot production on small holdings in Turkey
Energy Conversion and Management 47 (2006) 3351–3359 www.elsevier.com/locate/enconman
Energy use on organic farming: A comparative analysis on organic versus conventional apricot production on small holdings in Turkey Erdemir Gu¨ndog˘musß
*
Faculty of Agriculture, Department of Agricultural Economics, Ankara University, Ankara 06110, Turkey Received 18 July 2005; accepted 30 January 2006 Available online 13 March 2006
Abstract The aim of this study was to compare the energy use in apricot production on organic and conventional farms in Turkey in terms of energy ratio, benefit/cost ratio and amount of renewable energy use. The total energy requirement under organic apricot farming was 13,779.35 MJ ha 1, whereas 22,811.68 MJ ha 1 was consumed under conventional apricot farming, i.e. 38% higher energy input was used on conventional apricot farming than the use on organic farms. The energy ratios of 2.22 and 1.45 were achieved under the organic and conventional farming systems, respectively. 2006 Elsevier Ltd. All rights reserved. Keywords: Energy requirement; Energy ratio; Organic farming; Apricot; Economics; Turkey
1. Introduction Today’s agricultural production relies heavily on the consumption of non-renewable fossil fuels. Consumption of fossil energy results in direct negative environmental effects through release of CO2 and other combustion gases. Indirectly, there have been positive effects: increased yields and reduced risk. Yet, large amounts of cheap fossil energy have indirect negative impacts on the environment like less diversified nature through the intensification of agricultural practices. Thus, looking for agricultural production methods with higher energy productivity is as topical today as it was some 20 years ago [1]. For implementation in agriculture of the general concept of sustainability, agronomists have proposed several solutions such as integrated arable farming systems and low input or organic farming [2–4]. Crop management systems need to be designed to help farmers maintain economic profitability while conserving external energy resources and farming in an environmentally responsible manner [5]. Effective energy use in agriculture is one of the conditions for sustainable agricultural production, since it provides financial savings, fossil fuels preservation and air pollution reduction [4]. Energy analysis can be *
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divided into two parts as direct and indirect energy. Direct energy is directly used at the farm and on fields for crops, but indirect energy is not directly consumed at the farm [6]. However, both direct and indirect forms of energy are required for agricultural production in terms of its development and growth. On the other hand, despite its importance, energy use can be very costly. Many studies have been conducted on agricultural energy use [7–19]. In some of them, energy analysis is only one part of the assessment of environmental impact due to human activities. This is especially true for approaches at the planet level, where men and their use of energy are considered only as an element of the ecological system [4]. However, most of the studies focused on a strict energy analysis where the energy efficiency, the energy intensity or the energy yield were assessed. At the farm scale, these allow the comparison of different crops used for food or bio-diesel [20,21], different farming systems like crops or breeding [22], different ways of production as conventional, low input or biodynamic practices [23–26]. There is only one research on energy analysis of apricot production. However, only conventional apricot production was the focus of that research [18]. The authors have not found a thorough publication comparatively analyzing energy input and output on organic versus conventional apricot production systems. Therefore, there is an immediate need to conduct such an analysis to provide the basis for future steps to be taken for any improvements of organic apricot production. The objective of the present study was to compare the energy use of apricot production on organic and conventional farms in Turkey in terms of their energy output–input ratio, benefit/cost ratio and amount of renewable energy use. 2. Materials and methods 2.1. Selection of case study farms and data collection This study was conducted in the Malatya Province. The production of organic apricot, on average, is 12,800 tones in Turkey. About 91% of this production is obtained in the Malatya Province. The number of organic apricot producers is 171 [27]. Ten farm pairs, each of which consists of one organic and one conventional farm with less than 10 ha of apricot plantation, were selected in five districts of (Akc¸adag˘, Battalgazi, Darende, Hekimhan and Yazıhan) the Malatya Province with varying agro-ecological conditions. Each farm pair shared a similar biophysical and socioeconomic environment due to their proximity. Since there were fewer organic farms than conventional farms, organic farms were identified first, followed by selecting comparable nearby conventional counterparts. In order to be eligible for selection, organic farms had to: (a) have a history of at least three years under organic management (selected farms actually ranged from 5 to 9 years); (b) be subject to active management using organic principles; and (c) have the majority of apricot plantations in production. The last criterion was also applied to conventional farms. The conventional farms were selected primarily according to proximity to their respective organic counterparts and the similarity of altitude and area under apricot plants. On the farms studied, accounting records do not exist. Although the most crucial materials to be supplied for agricultural economics researches are sufficient and reliable data in farm records, data gathered by surveys are also suitable and are a dependable method in cases where these records do not exist [28]. In the study, the survey used in order to collect data from the producers was formed by discussing with experts on this subject. Pre-testong of the questionnaire forms prepared was done in some local areas. Therefore, the application of the survey forms facilitated providing sufficient information for the aims of the study. Data were collected for a three year period (2002–2004) via repeated semi-structured interviews with producers and corroborated with farm visits. In addition, the studies and statistics concerning the subject and research area of some organizations such as the Agricultural Directorate, Farmer’s Chamber, agricultural input suppliers, Union of Apricot Sales Cooperative (Kayısıbirlik), Industry and Trade Chamber of the Malatya Province and export firms were also utilized. 2.2. Energy equivalents used The energy equivalents of the inputs used in the apricot production are illustrated in Table 1. The data of energy use have been taken from a number of sources, as indicated in the table. The sources of mechanical
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Table 1 Energy equivalents of different input and output values used Equipment/input Human labor (h) Machinery (h) Chemical fertilizers (kg) Nitrogen Phosphorus Potassium Farm manure (kg) Pesticides (kg) Insecticides Fungicides Herbicides Diesel–oil (l) Electricity (kW h) Irrigation water (m3) Output (kg) Apricot fruit Apricot pits
Energy coefficients (MJ/unit) 1.96 62.70
References
199 92 238 56.31 11.93 0.63
[29] [29] [29] [29] [29] [29] [29] [29] [30] [30] [30] [29] [29] [31]
1.90 9.00
[29] [18]
60.60 11.10 6.70 0.30
energy used on the selected farms included tractor power and Diesel. The mechanical energy was computed on the basis of total fuel consumption (ha 1) in the different operations. The energy consumed was calculated using conversion factors (1 l Diesel = 56.31 MJ) and the same was expressed in MJ/ha. Based on the energy equivalents of the inputs and outputs, the metabolic energy was calculated. The energy ratio was found by dividing the total energy equivalents of the inputs into the total energy equivalent of the yield of apricot for each production system. 2.3. Productivity and profitability evaluation For analysis of apricot production for producer’s welfare, partial budget analysis was done [32]. Total production costs and unit cost of product were calculated by adding variable costs with fixed costs, such as depreciation, interest, management, maintenance etc. Productivity was calculated from interviews with farmers. The net income of apricot production activity was calculated as gross product value (GPV) minus production costs. The benefit/cost ratio was calculated by dividing GPV into total production costs. 3. Results The research results cover three main components; namely the energy requirements of organic and conventional farms of apricot production along with the energy input–output relationships, energetics of producing apricots and economic results of the production activity. 3.1. Energy requirements and input output relationships of apricot production Generally, 50 HP tractors were used for tillage and other cultural practices on both production systems. Soil cultivation activities are performed mainly between November and April (Table 2). In this study, the most commonly used operations and equipments were taken as the base for the research sample. The first tillage done by plough starts in November and continues until March–April. The number of average tillings is higher on conventional farms. The two production systems show differences in terms of fertilization period. The period between October and December is suitable for organic apricot production because of using farm manure only. Conventional farms generally use chemical fertilizers in the period of March–April. Insecticides and fungicides are commonly used on conventional farms. The average number of sprayings during the production season is much more in conventional production than organic apricot production.
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Table 2 Management practices for apricot production Production processes
Conventional farms
Organic farms
Common varieties Number of trees (ha) Soil cultivations (50 hp tractor used)
Hacıhalilog˘lu, Kabaasßı, Hasanbey, 260–350 First tilling is applied between November and December using plough, the second and third tilling is applied between March–April using disc-harrow 3.1 November–December March–April 2.8 February–June 5.6 November–April 1.4 June–September 4.5 July–August
Hacıhalilog˘lu, Kabaasßı, Hasanbey 275–350 First tilling is applied between November and December using plough, the second tilling is applied between March–April using disc-harrow
Average tilling number Pruning period Fertilization period Average number of fertilization Spraying period Average number of spraying Hoeing period Average number of hoeing Irrigation period Average number of irrigation Harvesting period
2.3 November–December October–December 1.2 February–June 4.8 November–April 1.9 June–September 4.1 July–August
Some sort of organic preparations and fungicides that are permitted in organic management are used for fungus control. The average number of hoeings on organic farms is relatively much more than the number on conventional farms. While the irrigation period is nearly the same on both production systems, the number of irrigations is much more on conventional farms. Apricots are harvested by hand in the period of July and August. The inputs used in organic apricot production and their energy equivalents, output energy equivalent and energy ratio are illustrated in Table 3. The results revealed that 645.9 h of human labor and 14.7 h of machinery (tractor) power per hectare were needed to produce organic apricot in the researched area. The 53.29% of the total human labor was spent on cultural practices (soil cultivation, pruning, fertilization, pest control, irrigation etc.), and the remainder was spent on harvesting. Cultural practices have the biggest proportional share (65.99%) of the total machinery power used on organic apricot production, followed by soil cultivation (26.53%) and transportation (7.48%). The total energy used in the various production processes for producing organic apricot was 13,779.35 MJ/ ha. Of all the production processes in apricot production, fossil fuel (Diesel) consumed the most energy (44.99%), followed by fungicides (25.57%), human labor (9.19%) and electricity (7.01%). The Diesel energy was mainly utilized for operating tractors to perform the various farm operations. The energy input of farm manure took a share of 5.23% in the total energy input use. In the researched area, the three year mean yields of apricot fruit and apricot pits were calculated as 12,404.0 kg ha 1and 776.4 kg ha 1, respectively. The total energy output per hectare was calculated as 30,555.20 MJ for organic apricot production. Therefore, the energy ratio of organic apricot production was calculated as 2.22. The input–output relationships and their energy equivalents of the conventional apricot production are presented in Table 4. The human labor use on conventional apricot production was estimated to be 594.6 h ha 1. Contrary to organic production, the human labor energy used for cultural practices had less share in the total labor energy input on conventional apricot production. The machinery power used on conventional apricot production is higher than that of organic production with 16.3 h ha 1. Chemical fertilization usage on conventional farms was found to be 183.6 kg/ha. The shares of nitrogenous and phosphorus in total chemical fertilizer use were 75.54% and 24.46%, respectively. The total energy input for conventional apricot production was 22,811.68 MJ/ha. Gezer et al. [18] found this value as 22,340.95 MJ/ha. However, they found the total energy output nearly 2.2 times more than our figure because of using a higher coefficient for apricot fruit (3.36 MJ/kg). The chemical fertilizer was the
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Table 3 Energy consumption and energy input–output relationship on organic apricot production Input Human labor (h) Cultural practices Harvesting Machinery (h) Soil cultivation Cultural practices Transportation Chemical fertilizers (kg) Nitrogen Phosphorus Potassium Farm manure (kg) Pesticides (kg) Insecticides Fungicides Herbicides Diesel–oil (l) Electricity (kW h) Irrigation water (m3) Total energy input (MJ) Total energy output (MJ) Yield (apricot fruit)(kg) Yield (apricot pits)(kg) Energy output/input ratio a
Quantity per unit area (ha) 645.9 344.2 301.7 14.7 3.9 9.7 1.1 – – – – 2402.0 38.3a – 38.3 – 110.1 81.0 288.0
12,404.0 776.4
Energy equivalent (MJ/unit) 1.96 1.96 1.96 62.70 62.70 62.70 62.70 60.60 11.10 6.70 0.30 199.00 92.00 238.00 56.31 11.93 0.63
1.90 9.00
Total energy equivalent (MJ) 1,265.96 674.63 591.33 921.69 244.53 608.19 68.97 – – – – 720.60 3523.60 – 3523.60 – 6199.73 966.33 181.44 13,779.35 30,555.20 23,567.60 6987.60 2.22
Percentage of total energy input (%) 9.19 4.90 4.29 6.69 1.78 4.41 0.50 – – – – 5.23 25.57 – 25.57 – 44.99 7.01 1.32 100.00
Fungicides that permitted on organic farming.
Table 4 Energy consumption and energy input–output relationship on conventional apricot production Input Human labor (h) Cultural practices Harvesting Machinery (h) Soil cultivation Cultural practices Transportation Chemical fertilizers (kg) Nitrogen Phosphorus Potassium Farm manure (kg) Pesticides Insecticides Fungicides Herbicides Diesel–oil (l) Electricity (kW h) Irrigation water (m3) Total energy input (MJ) Total energy output (MJ) Yield (apricot fruit)(kg) Yield (apricot pits)(kg) Energy output/input ratio
Quantity per unit area (ha) 594.6 279.1 315.5 16.3 4.1 10.7 1.5 183.6 138.7 44.9 – 741.9 34.4 0.9 33.5 – 132.3 49.4 314.0
13,592.0 815.7
Energy equivalent (MJ/unit)
Total energy equivalent (MJ)
1.96 1.96 1.96 62.70 62.70 62.70 62.70 60.60 11.10 6.70 0.30 199.00 92.00 238.00 56.31 11.93 0.63
1.90 9.00
1165.42 547.04 618.38 1022.01 257.07 670.89 94.05 8903.61 8405.22 498.39 – 222.57 3261.10 179.10 3082.00 – 7449.81 589.34 197.82 22,811.68 33,166.10 25,824.80 7341.30 1.45
Percentage of total energy input (%) 7.95 2.33 5.62 4.35 1.10 2.85 0.40 37.86 35.74 2.12 – 0.95 13.87 0.76 13.11 – 31.68 2.50 0.84 100.00
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highest in total energy input use with the value of 8903.61 MJ/ha, followed by Diesel (7449.81 MJ/ha) and pesticides (3261.10 MJ/ha). The contributions of, machinery, irrigation, farm manure and human labor inputs remained at relatively low levels. The three year mean yields of apricot fruit and apricot pits were calculated as 13,592 kg ha 1 and 815.7 kg ha 1, respectively. The total energy output on conventional apricot production was found as 33,166.10 MJ/ha. Therefore, the energy ratio of organic apricot production was calculated as 1.45. 3.2. Energetics of producing apricot The total mean energy input as direct and indirect, renewable and non-renewable forms is illustrated in Table 5. As can be seen, the maximum energy is required on conventional apricot production. The total energy input use on organic apricot production is 38% lower than that of conventional production. In other words, organic apricot production needs only 62.0% of the conventional apricot production total energy input use. Scialabba and Hattam [33] determined that the energy input use per hectare in the same production activity on organic farms was less than that on conventional farms. Namely, the organic farms use 90% of the total energy input applied on conventional farms in apple production, between 54% and 73% in potato production, between 35% and 59% in winter wheat production and between 31% and 77% in milk production [33]. The share of direct energy input is higher on organic apricot production. The share of renewable energy input use in the total energy input is 14.42% on organic apricot production and 6.08% on conventional production. 3.3. Net income and benefit/cost ratio of apricot production systems The production cost and gross product values of both production systems are given in Table 6. According to the research results, the production costs per hectare are nearly the same on both production systems. Also, the mean GPV and net incomes on conventional apricot production are calculated as 3% higher than those of organic production. In the research, the benefit–cost ratio of apricot production was calculated by dividing the gross product value into the total production cost to determine the economic efficiency. The benefit–cost ratios are nearly the same on both production systems.
Table 5 Total energy input in the form of direct and indirect renewable and non-renewable on apricot production Farming types
Organic Conventional Organic/con. · 100
Total energy input (MJ/ha)
Energy forms (MJ/ha) Direct energya
Indirect energyb
Renewable energyc
Non-renewable energyd
13,779.35 22,811.68 62
8432.02 (61.19) 9204.57 (40.35) 92
5165.89 (37.49) 13,409.29 (58.78) 39
1986.56 (14.42) 1387.99 (6.08) 143
11,611.35 (84.27) 21,225.87 (93.05) 55
Figures in parentheses indicate percentage of total energy input. a Includes human, animal, diesel and electricity energy sources. b Includes seeds, fertilizers, manure, chemicals and machinery energy sources. c Includes human, animal, seeds and manure. d Includes diesel, electricity, pesticides, fertilizers and machinery.
Table 6 Economic results of organic and conventional apricot production Farming types
Cost of production (US $ ha 1)
Gross product value (US $ ha 1)
Net income (US $ ha 1)
Benefit/cost ratio
Organic Conventional Organic/con. · 100
2225.3 2265.9 98
4742.1 4843.0 97
2516.8 2577.1 97
2.13 2.14 99
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4. Discussion 4.1. Energy requirements and input–output relationships of apricot production Total energy input use on conventional apricot production is about 9032.33 MJ/ha, which is more than that of organic production. The main factor resulting in excessive energy use on conventional production is chemical fertilizer use. On the other hand, energy use at different stages of production such as machinery, irrigation and Diesel is also higher than those of organic production. On organic production, the energy use of human labor, farm manure and electricity are relatively higher than those of conventional production. The three year mean apricot yield on the organic group is 8.74% lower than that on the conventional group. While the apricot yields are lower on organic farms, the energy output–input ratio is higher on the organic group with the value of 2.2, on average. The difference of organic agriculture appeared in terms of energy efficiency. 4.2. Energetics of producing apricot Of the total energy input use on organic apricot production, 1986.56 MJ/ha is renewable energy, which is 598.57 MJ/ha higher than that of conventional apricot production. On the other hand, while the share of renewable energy in the total energy input use on organic farms increases up to 14.42%, the ratio is only 6.8% on conventional farms. In other words, 45% less non-renewable energy is used on organic apricot production per hectare than on conventional apricot production. 4.3. Net income and benefit/cost ratio of apricot production systems It was determined that the cost of production per hectare on organic farms was 2% less than that on conventional farms, and the gross product value and net income were 3% less than on conventional farms. While 38% less energy input was spent on organic apricot production, the benefit–cost ratios are on the same level in both production systems. This condition is considerably the result of the sale prices of organic apricots being 8% higher than those of conventional farms. 5. Conclusion In this study, the energy requirements of inputs and output for organic and conventional apricot production were examined in the Malatya Province of Turkey. Data for the production of apricot were collected from 10 farm pairs on both production systems. The research results revealed that the energy input use on organic production was 38% lower than that on conventional production. The energy input of chemical fertilizer (37.86%) on conventional apricot production has the biggest share in the total energy inputs. On organic apricot production, the energy input of diesel (44.99%) has the most share in the total energy inputs. On average, the renewable energy form of energy input was 14.42% of the total energy input used on organic apricot production. The ratio was calculated as 6.08% on conventional apricot production. It is clear that the use of renewable energy on conventional farms is very low, indicating conventional apricot production depends mainly on fossil fuels. Furthermore, it implies that conventional apricot farming is very sensitive to possible changes in prices and supply availability of fossil fuels. Agriculture produces food and other raw materials as the basis for human life. However, rural areas in industrialized and in developing countries suffer from drifts to the cities, although they offer a wider range of renewable resources not being used yet. Urban lifestyle seems to promise more attractive opportunities, mostly based on extensive use of energy, but cities cannot survive without the countryside’s natural resources. Conventional agriculture has increased its fossil resources consumption enormously to achieve higher yields combined with a decrease of rural job opportunities. The utilization of fossil resources in agriculture threatens fertility of the soil and weakens the economic independence of farmers. Besides, fossil resources consumption in both urban and rural areas has lead to enormous ecological threats like climate change.
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The agricultural sector is a key sector, which has to be re-vitalized by new, integrated approaches, fully based on renewable resources, which can free farmers from depending on fossil resources. Combining renewable energies and organic agriculture offers tremendous synergies for sustainable development. Thus, the agricultural sector can regain its role as an economic core sector, offering attractive living conditions in rural areas. The use of inputs is still increasing, and energy related problems associated with agricultural production are still occurring. For this reason, it is necessary to promote development of new technologies and use of alternative energy sources. It is suggested that some specific policies be taken to reduce the negative effects of energy use such as pollution, global warming and nutrient loading. Within this framework, energy analysis is important to make improvements that will lead to more efficient and environmentally friendly production systems. Acknowledgements This work would have been impossible except for the participating producers, all of whom shared their time and knowledge generously, the staff of Malatya Provincial Directorate of MARA and Union of Apricot Sales Cooperative (Kayısıbirlik). I also thank the anonymous reviewers. References [1] Refsgaard K, Halberg N, Kristensen ES. Energy utilization in crop and dairy production in organic and conventional livestock production systems. Agric Syst 1998;57:599–630. [2] Vereijken P. A methodical way of prototyping integrated and ecological arable farming systems (I/EAFS) in interaction with pilot farms. Eur J Agronomy 1997;7:235–50. [3] Edwards CA. The concept of integrated systems in lower input/sustainable agriculture. Am J Alternative Agric 1987;2:148–52. [4] Pervanchon F, Bockstaller C, Girardin P. Assessment of energy use in arable farming systems by means of an agro-ecological indicator: the energy indicator. Agric Syst 2002;72:149–72. [5] Franzluebbers AJ, Francis CA. Energy output–input ratio of maize and sorghum management systems in Eastern Nebraska. Agric, Ecosyst Environ 1995(3):271–8. [6] Ozkan B, Akcaoz H, Karadeniz F. Energy requirement and economic analysis of citrus production in Turkey. Energ Convers Manage 2004;45(11–12):1821–30. [7] Ram RA, Raghuvanshi NK, Arya, SV. Study on energy cost requirements for wheat cultivation. Paper No: 80–105, Presented at ISAE. XVII Annual Convention, New Delhi, February 6–8, 1980. [8] Pathak B, Binning AS. Energy use pattern and potential for energy saving in rice–wheat cultivation. Agric Energ 1985;4:271–8. [9] Yadav RN, Singh RKP, Prasad S. An economic analysis of energy requirements in the production of potato crop in Bihar Sharif Block of Nalanda district (Bihar). Econ Affair, Kolkatta 1991;36:112–9. [10] Singh S, Singp G. Energy input crop yield relationship for four major crops of Northern India. Agric Mech Asia, Africa Latin America 1992;23(2):57–61. [11] Thakur CL, Mishra BL. Energy requirements and energy gaps for production of major crops in Madhya Pradesh. Agric Situation India 1993;48:665–89. [12] Baruah DC, Bhattacharya PC. Utilization pattern of human and fuel energy in tea plantation. J Agric Soil Sci 1995;8(2):189–92. [13] Singh S, Verma SR, Mittal JP. Energy requirements for production of major crops in India. Agric Mech Asia, Africa Latin America 1997;28(4):13–7. [14] Singh JM. On farm energy use pattern in different cropping systems in Haryana, India. MSc. Thesis. Germany: International Institute of Management, University of Flensburg, Sustainable Energy Systems and Management; 2000. [15] Chandra H, Dipanker D, Singh RS. Spatial variation in energy use pattern for paddy cultivation in India. In: Proc of national workshop on energy and environment management for sustainable development of agriculture and agro industrial sector. 2001;(July 8–9):48–51. [16] Ozkan B, Kurklu A, Akcaoz H. An output–input energy analysis in greenhouse vegetable production: a case study for Antalya region of Turkey. Biomass Bioenerg 2003;26:189–95. [17] Mandal KG, Saha KP, Ghosh PK, Hati KM, Mandyopadhyay KK. Bioenergy and economic analysis of soybean based crop production systems in central India. Biomass Bioenerg 2002;23(5):337–45. [18] Gezer I, Acaroglu M, Haciseferogullari H. Use of energy and labour in apricot agriculture in Turkey. Biomass Bioenerg 2003;24(3):215–9. [19] Jolliet O. Ecological assessment of thermal, mechanical and chemical procedures for drying potato slices. Revue Suisse Agricole 1994;2:83–90. [20] Batchelor SE, Booth EJ, Walker KC. Energy analysis of rape methyl ester (RME) production from winter oilseed. Ind Crops Prod 1995;4:193–202.
E. Gu¨ndog˘musß / Energy Conversion and Management 47 (2006) 3351–3359
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[21] Jossart JM, Vanhemelryck JL, Ledent JF. Environmental impact of three energy cultures and evaluation of energy. Ciers de l’Agriculture 1995;4:377–82. [22] Halberg N, Kristensen ES, Refsgaard K. Energy use in crop production on Danish mixed farms: systems modelling of data from farm studies. In: International symposium: systems-orientated research in agriculture and rural development. Montpellier, France: 1994. [23] Alfo¨di T, Niggli U, Spiess E, Besson JM. Input and output of energy for different crops in bio-dynamic, bio-organic and conventional production systems in a long term field trial in Switzerland. Bull SGPW/SSA 1995;4:38. [24] Pimentel D. Economics and energetics of organic and conventional farming. J Agric Environ Ethics 1993;6(1):53–9. [25] Pimentel D, Berardi G, Fast S. Energy efficiency of farming systems; organic and conventional agriculture. Agric, Ecosyst Environ 1983;9:359–72. [26] Corre´ WJ, Schro¨der JJ, Verhagen A. Energy use in conventional and organic farming systems. Proc 511. York UK: International Fertiliser Society; 2003. p. 23. [27] Ministry of Agriculture and Rural Affairs, Records of General Directorate of Research, Planning and Coordination, (1985–2002), Ankara, Turkey, unpublished. [28] Yang WF. Methods of study and research in agricultural management, Translator: Metin Talim, E.U.Ziraat Fakultesi Yayin No: 90, Ege Universitesi Matbaasi, 1986, Izmir, Turkey. [29] Singh H, Mishra D, Nahar NM. Energy use pattern in production agriculture of a typical village in arid zone India-Part I. Energy Convers Manage 2002. [30] Hessel ZR. Energy and alternatives for fertiliser and pesticide use. In: Flick RC, editor. Energy in world agriculture, 6. Elsevier Science Publishing; 1992. p. 177–210. [31] Yaldiz O, Oztu¨rk HH, Zeren Y, Bascentincelik A. Energy use in field crops of Turkey fifth international congress of agricultural machinery and energy, Kusadasi, Turkey, 1993 (in Turkish). [32] Lampkin N, Padel S. The economics of organic farming. an international perspective. Oxford: CAB International; 1994. [33] Scialabba N-H, Hattam C. Organic agriculture, environment and food security. Environ Nat Resour Ser, vol. 4. Rome: FAO; 2002.
Energy use on organic farming: A comparative analysis on organic versus conventional apricot production on small holdings in Turkey Erdemir Gu¨ndog˘musß
*
Faculty of Agriculture, Department of Agricultural Economics, Ankara University, Ankara 06110, Turkey Received 18 July 2005; accepted 30 January 2006 Available online 13 March 2006
Abstract The aim of this study was to compare the energy use in apricot production on organic and conventional farms in Turkey in terms of energy ratio, benefit/cost ratio and amount of renewable energy use. The total energy requirement under organic apricot farming was 13,779.35 MJ ha 1, whereas 22,811.68 MJ ha 1 was consumed under conventional apricot farming, i.e. 38% higher energy input was used on conventional apricot farming than the use on organic farms. The energy ratios of 2.22 and 1.45 were achieved under the organic and conventional farming systems, respectively. 2006 Elsevier Ltd. All rights reserved. Keywords: Energy requirement; Energy ratio; Organic farming; Apricot; Economics; Turkey
1. Introduction Today’s agricultural production relies heavily on the consumption of non-renewable fossil fuels. Consumption of fossil energy results in direct negative environmental effects through release of CO2 and other combustion gases. Indirectly, there have been positive effects: increased yields and reduced risk. Yet, large amounts of cheap fossil energy have indirect negative impacts on the environment like less diversified nature through the intensification of agricultural practices. Thus, looking for agricultural production methods with higher energy productivity is as topical today as it was some 20 years ago [1]. For implementation in agriculture of the general concept of sustainability, agronomists have proposed several solutions such as integrated arable farming systems and low input or organic farming [2–4]. Crop management systems need to be designed to help farmers maintain economic profitability while conserving external energy resources and farming in an environmentally responsible manner [5]. Effective energy use in agriculture is one of the conditions for sustainable agricultural production, since it provides financial savings, fossil fuels preservation and air pollution reduction [4]. Energy analysis can be *
Tel.: +90 312 596 17 33; fax: +90 312 318 53 60. E-mail address: [email protected]
0196-8904/$ - see front matter 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.enconman.2006.01.001
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divided into two parts as direct and indirect energy. Direct energy is directly used at the farm and on fields for crops, but indirect energy is not directly consumed at the farm [6]. However, both direct and indirect forms of energy are required for agricultural production in terms of its development and growth. On the other hand, despite its importance, energy use can be very costly. Many studies have been conducted on agricultural energy use [7–19]. In some of them, energy analysis is only one part of the assessment of environmental impact due to human activities. This is especially true for approaches at the planet level, where men and their use of energy are considered only as an element of the ecological system [4]. However, most of the studies focused on a strict energy analysis where the energy efficiency, the energy intensity or the energy yield were assessed. At the farm scale, these allow the comparison of different crops used for food or bio-diesel [20,21], different farming systems like crops or breeding [22], different ways of production as conventional, low input or biodynamic practices [23–26]. There is only one research on energy analysis of apricot production. However, only conventional apricot production was the focus of that research [18]. The authors have not found a thorough publication comparatively analyzing energy input and output on organic versus conventional apricot production systems. Therefore, there is an immediate need to conduct such an analysis to provide the basis for future steps to be taken for any improvements of organic apricot production. The objective of the present study was to compare the energy use of apricot production on organic and conventional farms in Turkey in terms of their energy output–input ratio, benefit/cost ratio and amount of renewable energy use. 2. Materials and methods 2.1. Selection of case study farms and data collection This study was conducted in the Malatya Province. The production of organic apricot, on average, is 12,800 tones in Turkey. About 91% of this production is obtained in the Malatya Province. The number of organic apricot producers is 171 [27]. Ten farm pairs, each of which consists of one organic and one conventional farm with less than 10 ha of apricot plantation, were selected in five districts of (Akc¸adag˘, Battalgazi, Darende, Hekimhan and Yazıhan) the Malatya Province with varying agro-ecological conditions. Each farm pair shared a similar biophysical and socioeconomic environment due to their proximity. Since there were fewer organic farms than conventional farms, organic farms were identified first, followed by selecting comparable nearby conventional counterparts. In order to be eligible for selection, organic farms had to: (a) have a history of at least three years under organic management (selected farms actually ranged from 5 to 9 years); (b) be subject to active management using organic principles; and (c) have the majority of apricot plantations in production. The last criterion was also applied to conventional farms. The conventional farms were selected primarily according to proximity to their respective organic counterparts and the similarity of altitude and area under apricot plants. On the farms studied, accounting records do not exist. Although the most crucial materials to be supplied for agricultural economics researches are sufficient and reliable data in farm records, data gathered by surveys are also suitable and are a dependable method in cases where these records do not exist [28]. In the study, the survey used in order to collect data from the producers was formed by discussing with experts on this subject. Pre-testong of the questionnaire forms prepared was done in some local areas. Therefore, the application of the survey forms facilitated providing sufficient information for the aims of the study. Data were collected for a three year period (2002–2004) via repeated semi-structured interviews with producers and corroborated with farm visits. In addition, the studies and statistics concerning the subject and research area of some organizations such as the Agricultural Directorate, Farmer’s Chamber, agricultural input suppliers, Union of Apricot Sales Cooperative (Kayısıbirlik), Industry and Trade Chamber of the Malatya Province and export firms were also utilized. 2.2. Energy equivalents used The energy equivalents of the inputs used in the apricot production are illustrated in Table 1. The data of energy use have been taken from a number of sources, as indicated in the table. The sources of mechanical
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Table 1 Energy equivalents of different input and output values used Equipment/input Human labor (h) Machinery (h) Chemical fertilizers (kg) Nitrogen Phosphorus Potassium Farm manure (kg) Pesticides (kg) Insecticides Fungicides Herbicides Diesel–oil (l) Electricity (kW h) Irrigation water (m3) Output (kg) Apricot fruit Apricot pits
Energy coefficients (MJ/unit) 1.96 62.70
References
199 92 238 56.31 11.93 0.63
[29] [29] [29] [29] [29] [29] [29] [29] [30] [30] [30] [29] [29] [31]
1.90 9.00
[29] [18]
60.60 11.10 6.70 0.30
energy used on the selected farms included tractor power and Diesel. The mechanical energy was computed on the basis of total fuel consumption (ha 1) in the different operations. The energy consumed was calculated using conversion factors (1 l Diesel = 56.31 MJ) and the same was expressed in MJ/ha. Based on the energy equivalents of the inputs and outputs, the metabolic energy was calculated. The energy ratio was found by dividing the total energy equivalents of the inputs into the total energy equivalent of the yield of apricot for each production system. 2.3. Productivity and profitability evaluation For analysis of apricot production for producer’s welfare, partial budget analysis was done [32]. Total production costs and unit cost of product were calculated by adding variable costs with fixed costs, such as depreciation, interest, management, maintenance etc. Productivity was calculated from interviews with farmers. The net income of apricot production activity was calculated as gross product value (GPV) minus production costs. The benefit/cost ratio was calculated by dividing GPV into total production costs. 3. Results The research results cover three main components; namely the energy requirements of organic and conventional farms of apricot production along with the energy input–output relationships, energetics of producing apricots and economic results of the production activity. 3.1. Energy requirements and input output relationships of apricot production Generally, 50 HP tractors were used for tillage and other cultural practices on both production systems. Soil cultivation activities are performed mainly between November and April (Table 2). In this study, the most commonly used operations and equipments were taken as the base for the research sample. The first tillage done by plough starts in November and continues until March–April. The number of average tillings is higher on conventional farms. The two production systems show differences in terms of fertilization period. The period between October and December is suitable for organic apricot production because of using farm manure only. Conventional farms generally use chemical fertilizers in the period of March–April. Insecticides and fungicides are commonly used on conventional farms. The average number of sprayings during the production season is much more in conventional production than organic apricot production.
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Table 2 Management practices for apricot production Production processes
Conventional farms
Organic farms
Common varieties Number of trees (ha) Soil cultivations (50 hp tractor used)
Hacıhalilog˘lu, Kabaasßı, Hasanbey, 260–350 First tilling is applied between November and December using plough, the second and third tilling is applied between March–April using disc-harrow 3.1 November–December March–April 2.8 February–June 5.6 November–April 1.4 June–September 4.5 July–August
Hacıhalilog˘lu, Kabaasßı, Hasanbey 275–350 First tilling is applied between November and December using plough, the second tilling is applied between March–April using disc-harrow
Average tilling number Pruning period Fertilization period Average number of fertilization Spraying period Average number of spraying Hoeing period Average number of hoeing Irrigation period Average number of irrigation Harvesting period
2.3 November–December October–December 1.2 February–June 4.8 November–April 1.9 June–September 4.1 July–August
Some sort of organic preparations and fungicides that are permitted in organic management are used for fungus control. The average number of hoeings on organic farms is relatively much more than the number on conventional farms. While the irrigation period is nearly the same on both production systems, the number of irrigations is much more on conventional farms. Apricots are harvested by hand in the period of July and August. The inputs used in organic apricot production and their energy equivalents, output energy equivalent and energy ratio are illustrated in Table 3. The results revealed that 645.9 h of human labor and 14.7 h of machinery (tractor) power per hectare were needed to produce organic apricot in the researched area. The 53.29% of the total human labor was spent on cultural practices (soil cultivation, pruning, fertilization, pest control, irrigation etc.), and the remainder was spent on harvesting. Cultural practices have the biggest proportional share (65.99%) of the total machinery power used on organic apricot production, followed by soil cultivation (26.53%) and transportation (7.48%). The total energy used in the various production processes for producing organic apricot was 13,779.35 MJ/ ha. Of all the production processes in apricot production, fossil fuel (Diesel) consumed the most energy (44.99%), followed by fungicides (25.57%), human labor (9.19%) and electricity (7.01%). The Diesel energy was mainly utilized for operating tractors to perform the various farm operations. The energy input of farm manure took a share of 5.23% in the total energy input use. In the researched area, the three year mean yields of apricot fruit and apricot pits were calculated as 12,404.0 kg ha 1and 776.4 kg ha 1, respectively. The total energy output per hectare was calculated as 30,555.20 MJ for organic apricot production. Therefore, the energy ratio of organic apricot production was calculated as 2.22. The input–output relationships and their energy equivalents of the conventional apricot production are presented in Table 4. The human labor use on conventional apricot production was estimated to be 594.6 h ha 1. Contrary to organic production, the human labor energy used for cultural practices had less share in the total labor energy input on conventional apricot production. The machinery power used on conventional apricot production is higher than that of organic production with 16.3 h ha 1. Chemical fertilization usage on conventional farms was found to be 183.6 kg/ha. The shares of nitrogenous and phosphorus in total chemical fertilizer use were 75.54% and 24.46%, respectively. The total energy input for conventional apricot production was 22,811.68 MJ/ha. Gezer et al. [18] found this value as 22,340.95 MJ/ha. However, they found the total energy output nearly 2.2 times more than our figure because of using a higher coefficient for apricot fruit (3.36 MJ/kg). The chemical fertilizer was the
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Table 3 Energy consumption and energy input–output relationship on organic apricot production Input Human labor (h) Cultural practices Harvesting Machinery (h) Soil cultivation Cultural practices Transportation Chemical fertilizers (kg) Nitrogen Phosphorus Potassium Farm manure (kg) Pesticides (kg) Insecticides Fungicides Herbicides Diesel–oil (l) Electricity (kW h) Irrigation water (m3) Total energy input (MJ) Total energy output (MJ) Yield (apricot fruit)(kg) Yield (apricot pits)(kg) Energy output/input ratio a
Quantity per unit area (ha) 645.9 344.2 301.7 14.7 3.9 9.7 1.1 – – – – 2402.0 38.3a – 38.3 – 110.1 81.0 288.0
12,404.0 776.4
Energy equivalent (MJ/unit) 1.96 1.96 1.96 62.70 62.70 62.70 62.70 60.60 11.10 6.70 0.30 199.00 92.00 238.00 56.31 11.93 0.63
1.90 9.00
Total energy equivalent (MJ) 1,265.96 674.63 591.33 921.69 244.53 608.19 68.97 – – – – 720.60 3523.60 – 3523.60 – 6199.73 966.33 181.44 13,779.35 30,555.20 23,567.60 6987.60 2.22
Percentage of total energy input (%) 9.19 4.90 4.29 6.69 1.78 4.41 0.50 – – – – 5.23 25.57 – 25.57 – 44.99 7.01 1.32 100.00
Fungicides that permitted on organic farming.
Table 4 Energy consumption and energy input–output relationship on conventional apricot production Input Human labor (h) Cultural practices Harvesting Machinery (h) Soil cultivation Cultural practices Transportation Chemical fertilizers (kg) Nitrogen Phosphorus Potassium Farm manure (kg) Pesticides Insecticides Fungicides Herbicides Diesel–oil (l) Electricity (kW h) Irrigation water (m3) Total energy input (MJ) Total energy output (MJ) Yield (apricot fruit)(kg) Yield (apricot pits)(kg) Energy output/input ratio
Quantity per unit area (ha) 594.6 279.1 315.5 16.3 4.1 10.7 1.5 183.6 138.7 44.9 – 741.9 34.4 0.9 33.5 – 132.3 49.4 314.0
13,592.0 815.7
Energy equivalent (MJ/unit)
Total energy equivalent (MJ)
1.96 1.96 1.96 62.70 62.70 62.70 62.70 60.60 11.10 6.70 0.30 199.00 92.00 238.00 56.31 11.93 0.63
1.90 9.00
1165.42 547.04 618.38 1022.01 257.07 670.89 94.05 8903.61 8405.22 498.39 – 222.57 3261.10 179.10 3082.00 – 7449.81 589.34 197.82 22,811.68 33,166.10 25,824.80 7341.30 1.45
Percentage of total energy input (%) 7.95 2.33 5.62 4.35 1.10 2.85 0.40 37.86 35.74 2.12 – 0.95 13.87 0.76 13.11 – 31.68 2.50 0.84 100.00
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highest in total energy input use with the value of 8903.61 MJ/ha, followed by Diesel (7449.81 MJ/ha) and pesticides (3261.10 MJ/ha). The contributions of, machinery, irrigation, farm manure and human labor inputs remained at relatively low levels. The three year mean yields of apricot fruit and apricot pits were calculated as 13,592 kg ha 1 and 815.7 kg ha 1, respectively. The total energy output on conventional apricot production was found as 33,166.10 MJ/ha. Therefore, the energy ratio of organic apricot production was calculated as 1.45. 3.2. Energetics of producing apricot The total mean energy input as direct and indirect, renewable and non-renewable forms is illustrated in Table 5. As can be seen, the maximum energy is required on conventional apricot production. The total energy input use on organic apricot production is 38% lower than that of conventional production. In other words, organic apricot production needs only 62.0% of the conventional apricot production total energy input use. Scialabba and Hattam [33] determined that the energy input use per hectare in the same production activity on organic farms was less than that on conventional farms. Namely, the organic farms use 90% of the total energy input applied on conventional farms in apple production, between 54% and 73% in potato production, between 35% and 59% in winter wheat production and between 31% and 77% in milk production [33]. The share of direct energy input is higher on organic apricot production. The share of renewable energy input use in the total energy input is 14.42% on organic apricot production and 6.08% on conventional production. 3.3. Net income and benefit/cost ratio of apricot production systems The production cost and gross product values of both production systems are given in Table 6. According to the research results, the production costs per hectare are nearly the same on both production systems. Also, the mean GPV and net incomes on conventional apricot production are calculated as 3% higher than those of organic production. In the research, the benefit–cost ratio of apricot production was calculated by dividing the gross product value into the total production cost to determine the economic efficiency. The benefit–cost ratios are nearly the same on both production systems.
Table 5 Total energy input in the form of direct and indirect renewable and non-renewable on apricot production Farming types
Organic Conventional Organic/con. · 100
Total energy input (MJ/ha)
Energy forms (MJ/ha) Direct energya
Indirect energyb
Renewable energyc
Non-renewable energyd
13,779.35 22,811.68 62
8432.02 (61.19) 9204.57 (40.35) 92
5165.89 (37.49) 13,409.29 (58.78) 39
1986.56 (14.42) 1387.99 (6.08) 143
11,611.35 (84.27) 21,225.87 (93.05) 55
Figures in parentheses indicate percentage of total energy input. a Includes human, animal, diesel and electricity energy sources. b Includes seeds, fertilizers, manure, chemicals and machinery energy sources. c Includes human, animal, seeds and manure. d Includes diesel, electricity, pesticides, fertilizers and machinery.
Table 6 Economic results of organic and conventional apricot production Farming types
Cost of production (US $ ha 1)
Gross product value (US $ ha 1)
Net income (US $ ha 1)
Benefit/cost ratio
Organic Conventional Organic/con. · 100
2225.3 2265.9 98
4742.1 4843.0 97
2516.8 2577.1 97
2.13 2.14 99
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4. Discussion 4.1. Energy requirements and input–output relationships of apricot production Total energy input use on conventional apricot production is about 9032.33 MJ/ha, which is more than that of organic production. The main factor resulting in excessive energy use on conventional production is chemical fertilizer use. On the other hand, energy use at different stages of production such as machinery, irrigation and Diesel is also higher than those of organic production. On organic production, the energy use of human labor, farm manure and electricity are relatively higher than those of conventional production. The three year mean apricot yield on the organic group is 8.74% lower than that on the conventional group. While the apricot yields are lower on organic farms, the energy output–input ratio is higher on the organic group with the value of 2.2, on average. The difference of organic agriculture appeared in terms of energy efficiency. 4.2. Energetics of producing apricot Of the total energy input use on organic apricot production, 1986.56 MJ/ha is renewable energy, which is 598.57 MJ/ha higher than that of conventional apricot production. On the other hand, while the share of renewable energy in the total energy input use on organic farms increases up to 14.42%, the ratio is only 6.8% on conventional farms. In other words, 45% less non-renewable energy is used on organic apricot production per hectare than on conventional apricot production. 4.3. Net income and benefit/cost ratio of apricot production systems It was determined that the cost of production per hectare on organic farms was 2% less than that on conventional farms, and the gross product value and net income were 3% less than on conventional farms. While 38% less energy input was spent on organic apricot production, the benefit–cost ratios are on the same level in both production systems. This condition is considerably the result of the sale prices of organic apricots being 8% higher than those of conventional farms. 5. Conclusion In this study, the energy requirements of inputs and output for organic and conventional apricot production were examined in the Malatya Province of Turkey. Data for the production of apricot were collected from 10 farm pairs on both production systems. The research results revealed that the energy input use on organic production was 38% lower than that on conventional production. The energy input of chemical fertilizer (37.86%) on conventional apricot production has the biggest share in the total energy inputs. On organic apricot production, the energy input of diesel (44.99%) has the most share in the total energy inputs. On average, the renewable energy form of energy input was 14.42% of the total energy input used on organic apricot production. The ratio was calculated as 6.08% on conventional apricot production. It is clear that the use of renewable energy on conventional farms is very low, indicating conventional apricot production depends mainly on fossil fuels. Furthermore, it implies that conventional apricot farming is very sensitive to possible changes in prices and supply availability of fossil fuels. Agriculture produces food and other raw materials as the basis for human life. However, rural areas in industrialized and in developing countries suffer from drifts to the cities, although they offer a wider range of renewable resources not being used yet. Urban lifestyle seems to promise more attractive opportunities, mostly based on extensive use of energy, but cities cannot survive without the countryside’s natural resources. Conventional agriculture has increased its fossil resources consumption enormously to achieve higher yields combined with a decrease of rural job opportunities. The utilization of fossil resources in agriculture threatens fertility of the soil and weakens the economic independence of farmers. Besides, fossil resources consumption in both urban and rural areas has lead to enormous ecological threats like climate change.
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The agricultural sector is a key sector, which has to be re-vitalized by new, integrated approaches, fully based on renewable resources, which can free farmers from depending on fossil resources. Combining renewable energies and organic agriculture offers tremendous synergies for sustainable development. Thus, the agricultural sector can regain its role as an economic core sector, offering attractive living conditions in rural areas. The use of inputs is still increasing, and energy related problems associated with agricultural production are still occurring. For this reason, it is necessary to promote development of new technologies and use of alternative energy sources. It is suggested that some specific policies be taken to reduce the negative effects of energy use such as pollution, global warming and nutrient loading. Within this framework, energy analysis is important to make improvements that will lead to more efficient and environmentally friendly production systems. Acknowledgements This work would have been impossible except for the participating producers, all of whom shared their time and knowledge generously, the staff of Malatya Provincial Directorate of MARA and Union of Apricot Sales Cooperative (Kayısıbirlik). I also thank the anonymous reviewers. References [1] Refsgaard K, Halberg N, Kristensen ES. Energy utilization in crop and dairy production in organic and conventional livestock production systems. Agric Syst 1998;57:599–630. [2] Vereijken P. A methodical way of prototyping integrated and ecological arable farming systems (I/EAFS) in interaction with pilot farms. Eur J Agronomy 1997;7:235–50. [3] Edwards CA. The concept of integrated systems in lower input/sustainable agriculture. Am J Alternative Agric 1987;2:148–52. [4] Pervanchon F, Bockstaller C, Girardin P. Assessment of energy use in arable farming systems by means of an agro-ecological indicator: the energy indicator. Agric Syst 2002;72:149–72. [5] Franzluebbers AJ, Francis CA. Energy output–input ratio of maize and sorghum management systems in Eastern Nebraska. Agric, Ecosyst Environ 1995(3):271–8. [6] Ozkan B, Akcaoz H, Karadeniz F. Energy requirement and economic analysis of citrus production in Turkey. Energ Convers Manage 2004;45(11–12):1821–30. [7] Ram RA, Raghuvanshi NK, Arya, SV. Study on energy cost requirements for wheat cultivation. Paper No: 80–105, Presented at ISAE. XVII Annual Convention, New Delhi, February 6–8, 1980. [8] Pathak B, Binning AS. Energy use pattern and potential for energy saving in rice–wheat cultivation. Agric Energ 1985;4:271–8. [9] Yadav RN, Singh RKP, Prasad S. An economic analysis of energy requirements in the production of potato crop in Bihar Sharif Block of Nalanda district (Bihar). Econ Affair, Kolkatta 1991;36:112–9. [10] Singh S, Singp G. Energy input crop yield relationship for four major crops of Northern India. Agric Mech Asia, Africa Latin America 1992;23(2):57–61. [11] Thakur CL, Mishra BL. Energy requirements and energy gaps for production of major crops in Madhya Pradesh. Agric Situation India 1993;48:665–89. [12] Baruah DC, Bhattacharya PC. Utilization pattern of human and fuel energy in tea plantation. J Agric Soil Sci 1995;8(2):189–92. [13] Singh S, Verma SR, Mittal JP. Energy requirements for production of major crops in India. Agric Mech Asia, Africa Latin America 1997;28(4):13–7. [14] Singh JM. On farm energy use pattern in different cropping systems in Haryana, India. MSc. Thesis. Germany: International Institute of Management, University of Flensburg, Sustainable Energy Systems and Management; 2000. [15] Chandra H, Dipanker D, Singh RS. Spatial variation in energy use pattern for paddy cultivation in India. In: Proc of national workshop on energy and environment management for sustainable development of agriculture and agro industrial sector. 2001;(July 8–9):48–51. [16] Ozkan B, Kurklu A, Akcaoz H. An output–input energy analysis in greenhouse vegetable production: a case study for Antalya region of Turkey. Biomass Bioenerg 2003;26:189–95. [17] Mandal KG, Saha KP, Ghosh PK, Hati KM, Mandyopadhyay KK. Bioenergy and economic analysis of soybean based crop production systems in central India. Biomass Bioenerg 2002;23(5):337–45. [18] Gezer I, Acaroglu M, Haciseferogullari H. Use of energy and labour in apricot agriculture in Turkey. Biomass Bioenerg 2003;24(3):215–9. [19] Jolliet O. Ecological assessment of thermal, mechanical and chemical procedures for drying potato slices. Revue Suisse Agricole 1994;2:83–90. [20] Batchelor SE, Booth EJ, Walker KC. Energy analysis of rape methyl ester (RME) production from winter oilseed. Ind Crops Prod 1995;4:193–202.
E. Gu¨ndog˘musß / Energy Conversion and Management 47 (2006) 3351–3359
3359
[21] Jossart JM, Vanhemelryck JL, Ledent JF. Environmental impact of three energy cultures and evaluation of energy. Ciers de l’Agriculture 1995;4:377–82. [22] Halberg N, Kristensen ES, Refsgaard K. Energy use in crop production on Danish mixed farms: systems modelling of data from farm studies. In: International symposium: systems-orientated research in agriculture and rural development. Montpellier, France: 1994. [23] Alfo¨di T, Niggli U, Spiess E, Besson JM. Input and output of energy for different crops in bio-dynamic, bio-organic and conventional production systems in a long term field trial in Switzerland. Bull SGPW/SSA 1995;4:38. [24] Pimentel D. Economics and energetics of organic and conventional farming. J Agric Environ Ethics 1993;6(1):53–9. [25] Pimentel D, Berardi G, Fast S. Energy efficiency of farming systems; organic and conventional agriculture. Agric, Ecosyst Environ 1983;9:359–72. [26] Corre´ WJ, Schro¨der JJ, Verhagen A. Energy use in conventional and organic farming systems. Proc 511. York UK: International Fertiliser Society; 2003. p. 23. [27] Ministry of Agriculture and Rural Affairs, Records of General Directorate of Research, Planning and Coordination, (1985–2002), Ankara, Turkey, unpublished. [28] Yang WF. Methods of study and research in agricultural management, Translator: Metin Talim, E.U.Ziraat Fakultesi Yayin No: 90, Ege Universitesi Matbaasi, 1986, Izmir, Turkey. [29] Singh H, Mishra D, Nahar NM. Energy use pattern in production agriculture of a typical village in arid zone India-Part I. Energy Convers Manage 2002. [30] Hessel ZR. Energy and alternatives for fertiliser and pesticide use. In: Flick RC, editor. Energy in world agriculture, 6. Elsevier Science Publishing; 1992. p. 177–210. [31] Yaldiz O, Oztu¨rk HH, Zeren Y, Bascentincelik A. Energy use in field crops of Turkey fifth international congress of agricultural machinery and energy, Kusadasi, Turkey, 1993 (in Turkish). [32] Lampkin N, Padel S. The economics of organic farming. an international perspective. Oxford: CAB International; 1994. [33] Scialabba N-H, Hattam C. Organic agriculture, environment and food security. Environ Nat Resour Ser, vol. 4. Rome: FAO; 2002.