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An input–output energy analysis in greenhouse vegetable production: a case study for Antalya region of Turkey
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Biomass and Bioenergy 26 (2004) 89 – 95
An input–output energy analysis in greenhouse vegetable production: a case study for Antalya region of Turkey Burhan Ozkana;∗ , Ahmet Kurklub , Handan Akcaoza a Department
b Department
of Agricultural Economics, Faculty of Agriculture, University of Akdeniz, Antalya 07058, Turkey of Agricultural Machinery, Faculty of Agriculture, University of Akdeniz, Antalya 07059, Turkey
Received 5 January 2003; received in revised form 10 February 2003; accepted 24 April 2003
Abstract The aim of this research was to examine the energy equivalents of inputs and output in greenhouse vegetable production in the Antalya province of Turkey. For this purpose, the data for the production of four greenhouse crops (tomato, cucumber, eggplant and pepper) were collected in eighty-eight greenhouse farms by questionnaire. The results revealed that cucumber production was the most energy intensive of among the four crops investigated. Cucumber production consumed a total of 134:77 GJha−1 followed by tomato with 127:32 GJha−1 . The consumption of energy by eggplants and pepper were 98.68 and 80:25 GJha−1 , respectively. The output–input energy ratio for greenhouse tomato, pepper, cucumber and eggplant were estimated to be 1.26, 0.99, 0.76 and 0.61, respectively. This indicated an intensive use of inputs in greenhouse vegetable production not accompanied by increase in the 7nal product. This can lead to problems associated with these inputs such as global warming, nutrient loading and pesticide pollution. Therefore, there is a need to pursue a new policy to force producers to undertake energy e8cient practices to increase the yield without diminishing natural resources. ? 2003 Elsevier Ltd. All rights reserved. Keywords: Energy equivalent; Energy Use; Input–output; Greenhouses; Vegetables; Antalya
Nomenclature
1. Introduction
n is the required sample size, N the number of holdings in target population, Nh the number of the population in h the strati7ed, Sh2 the variance of h the strati7ed, d the precision where (x − X ), z the reliability coe8cient (01.96 which represent the 95% reliability) and D2 the d2 =z 2 .
1.1. General situation
∗ Corresponding author. Tel.: +90-242-310-2475; fax: +90242-227-4564. E-mail address: [email protected] (B. Ozkan).
Agriculture is an important economic sector in Turkey despite its diminish share over time. It contributed 14% of gross domestic product (GDP) in 2000 and 10.6% of total exports. More than 40% of the total population of the country is engaged in agriculture, and operate 4 million farm holdings. Horticultural production is an important part of the agricultural sector in Turkey and an area for potential export growth. Total vegetable production
0961-9534/04/$ - see front matter ? 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0961-9534(03)00080-1
90
B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
was estimated at over 20 million tonnes produced on 785 000 ha. About 2.7% of total vegetable production was exported fresh, 2.3% was sold to processors, and the rest was consumed fresh. Vegetables are produced both on open 7elds and under cover. Turkish greenhouse production continues to show very rapid expansion as in all Mediterranean countries. In 1999 total greenhouse area was 18 994 ha of which 5264 ha was under glass and 13 730 ha was under plastic. As of 1999, the total undercover area of Turkey was 42 314 ha, i.e. about 10% of the total greenhouse area of Mediterranean countries is about 400 000 ha [1], where about 60 –70% of the European greenhouses are concentrated [2]. Greenhouse production in Turkey began in 1940s in glasshouses built in Antalya province [3], which is still the centre of such production due to the very favourable climatic conditions for protected cultivation. According to 1999 statistics, 81.8% of the glasshouses and 48.5% of the plastic houses of the country were located in Antalya (Table 1). Greenhouse production provides not only income to owners but also many employment opportunities. The vegetables produced most extensively are tomato, cucumber, eggplant and pepper. Vegetable production is mostly carried out as a family business and the technological and productivity levels are very low compared to developed countries. The average size of the greenhouses is around 0.3–0:5 ha. Tomato, cucumber, pepper and eggplant are dominant in greenhouse production, with the share of 90.2% in the total protected area. Among the four crops, tomato production takes the biggest share, of 50.1%. The shares of cucumber, pepper and eggplants
in the total production area are 22.3%, 10.4% and 7.4%, respectively [4]. 1.2. Energy analysis Direct and indirect forms of energy are required for agricultural production. Energy input–output analysis is usually used to evaluate the e8ciency and environmental impacts of the production systems. Some research has been conducted for 7eld-grown plants [5–15]. However, the authors have not come across publication analysing energy input and output in greenhouse vegetable production which is a very energy-intensive sector of the industry. Therefore, there was an immediate need to carry out such an analysis for future steps to be taken for any improvement in greenhouse production systems regarding the energy values of the inputs and the output. On this basis, this study is aimed at preparing an energy audit for greenhouse vegetable production.
2. Material and methods Data were collected from growers in Antalya province producing greenhouse vegetables, by using a face-to-face questionnaire in the production year 2001. The survey was carried out in 128 villages where important undercover production exists. A total of 88 growers was randomly selected from the villages using the strati7ed random sampling method. The greenhouse farms in the sample were strati7ed into two greenhouse size groups, by using the
Table 1 Distribution of protected area of Turkey and Antalya (ha) [4] Protected cultivation
Turkey
Antalya %
The share of Antalya in Turkey (%)
Area
%
Area
Glasshouse (a) Plastic house (b) Greenhouse (a + b) High plastic tunnels Low plastic tunnels
5264 13 730 18 994 4309 19 012
12.4 32.5 44.9 10.2 44.9
4306 6657 10 963 0822 1552
32.3 49.9 82.2 6.2 11.6
81.8 48.5 57.7 19.1 8.2
Total protected area
42 314
100.0
13 337
100.0
31.5
B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
91
Neyman method [16]: ( N h Sh ) n= 2 2 ; N D + Nh Sh2
the inputs to the total energy equivalent of the yield, for each vegetable.
where n is the required sample size, N the number of holdings in target population, Nh the number of the population in h the strati7ed, Sh2 the variance of h the strati7ed, d the precision where (x − X ), z the reliability coe8cient (01.96 which represent the 95% reliability) and D2 the d2 =z 2 . The permissible error in sample population was de7ned to be 5%, and the sample size was calculated to be 88 for 95% reliability. Socio-economic characteristics of the farms were also determined to support the present analysis. The energy equivalents of inputs used in the crop production are illustrated in Table 2. The data on energy use have been taken from a number of sources, as indicated in the table. The sources of mechanical energy used on the selected farms included tractors and diesel oil. The mechanical energy was computed on the basis of total fuel consumption (l ha−1 ) in diKerent operations. The energy consumed was calculated using conversion factors (1 l diesel=56:31 MJ) and expressed in MJha−1 . Energy use in the production of the vegetables investigated was calculated on a m−2 basis. Basic information on energy inputs and crop yields were used to calculate the metabolizable energy. The energy ratio was found by dividing the total energy equivalent of
3. Results
Table 2 Energy equivalents of inputs and outputs in agricultural production Input (Unit)
Energy equivalent, (MJ unit −1 )
Reference
Chemicals (kg) Human power (h) Machinery (h) Nitrogen fertilizer (kg) Phosphorus (kg) Potassium (kg) Manure (tonnes) Seeds (kg) Diesel- oil (l) Electricity (kW h) Water for irrigation (m3 ) Tomato, cucumber, eggplant, pepper
101.2 2.3 64.8 66.14 12.44 11.15 303.1 1.0 56.31 3.6 0.63
Yaldiz [10] Yaldiz [10] Singh [14] Shrestha [20] Shrestha [20] Shrestha [20] Yaldiz [10] Singh [14] Singh [14]
0.80
Yaldiz [10]
3.1. Socioeconomic characteristics of the greenhouse farms The average age of the growers was 53.9 years and the average size of farm family in survey households was 4.94 people, lower than the average (5.4 people) in the rural regions of Turkey [17]. In the research area, average farm size was determined as 4:8 ha which 7.81% of the farm area are used for the production of vegetable crops. 89%, 8.5% and 2.4% of the farm land was owned, rented and shared, respectively. The average number of tractors was 0.82. 3.2. Energy use in greenhouse tomato production The inputs used in tomato production and their energy equivalents, output energy equivalent and energy ratio are illustrated in Table 3. About 98:7 kg pest and disease control chemicals and 976 kg chemical fertilizer were used in greenhouse tomato production on a hectare basis. The shares of nitrogen fertilizer, phosphorus and potassium were 32.8%, 37.2% and 30.0%, respectively, in the total chemical fertilizer used. The use of human power and machinery were 3 248:2 and 46:3 h ha−1 . The total energy equivalent of inputs was calculated as 127:32 GJ ha−1 . Diesel-oil had the highest share, of 32.17%, followed by nitrogen fertilizer (16.62%), manure (16.24%) and electricity (12.44%), respectively. The energy inputs of seeds and water for irrigation were found to be quite low compared to the other inputs used in production. The average yield of tomatoes was found 200 tonnes ha−1 and its energy equivalent was calculated to be 160 GJha−1 . Based on these values, output–input energy ratio for greenhouse tomatoes was 1.26. 3.3. Energy use in greenhouse cucumber production The inputs, used in the cucumber production and their energy equivalents, together with the energy equivalent of the yield were illustrated in Table 4.
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B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
Table 3 Energy inputs, outputs and the ratio in greenhouse tomato production Inputs (unit) Chemicals (kg) Human power (h) Machinery (h) Nitrogen fertilizer (kg) Phosphorus (kg) Potassium (kg) Manure (tonnes) Seeds (kg) Diesel-oil (l) Electricity (kW h) Water for irrigation (m3 ) Total energy input (MJ ) Yield (kg ha−1 ) Energy Output–Input Ratio
Quantity per unit area (ha) 98.7 3 248.2 46.3 320.0 363.0 293.0 68.2 0.1 727.5 4 400.0 700.0 200 000:0
Total energy equivalent (MJ)
%
9 988.4 7 470.9 3 000.2 21 164.8 4 515.7 3 266.9 20 671.4 0.1 40 965.5 15 840.0 441.0 127 324:9 160 000:0 1:26
7.84 5.87 2.36 16.62 3.55 2.57 16.24 0.00 32.17 12.44 0.35 100:00
Total energy equivalent (MJ)
%
13 419.1 7 570.5 4 250.9 19 379.0 4 640.1 4 259.3 13 639.5 0.1 57 464.4 9 720.0 428.4 134 771:3 102 304:0 0:76
9.96 5.62 3.15 14.38 3.44 3.16 10.12 0.00 42.64 7.21 0.32 100:0
Table 4 Energy inputs, outputs and the ratio in greenhouse cucumber production Inputs (unit) Chemicals (kg) Human power (h) Machinery (h) Nitrogen fertilizer (kg) Phosphorus (kg) Potassium (kg) Manure (tonnes) Seeds (kg) Diesel-oil (l) Electricity (kW h) Water for irrigation (m3 ) Total energy input (MJ ) Yield (kg ha−1 ) Energy output–input Ratio
Quantity per unit area (ha) 132.6 3 291.5 65.6 293.0 373.0 382.0 45.0 0.1 1 020.5 2 700.0 680.0 127 880:0
As indicated in the table about 132:6 kg chemicals, 1048 kg chemical fertilizer and 45 t manure were used in greenhouse cucumber production on a hectare basis. The use of human power and machinery were 3 291:5 and 65:6 h ha−1 , respectively. Average cucumber yield was 127 880 kg ha−1 . The total energy input was calculated 134:77 GJ ha−1 . Diesel-oil was the energy input in the total with a share of 42.64%. This was followed by nitrogen
fertilizer (14.38%), manure (10.12%) and chemicals (9.96%). Based on these values output–input energy ratio for greenhouse cucumber was 0.76. 3.4. Energy use in greenhouse eggplant production Table 5 shows the inputs, their energy equivalents, energy equivalent of the yield and the ratio. The research has shown that about 131:0 kg chemicals,
B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
93
Table 5 Energy inputs, outputs and the ratio in greenhouse eggplant production Inputs (unit) Chemicals (kg) Human power (h) Machinery (h) Nitrogen fertilizer (kg) Phosphorus (kg) Potassium (kg) Manure (tonnes) Seeds (kg) Diesel-oil (l) Electricity (kW h) Water for irrigation (m3 ) Total Energy Input (MJ ) Yield (kg ha−1 ) Energy output–input Ratio
Quantity per unit area (ha) 131.0 1 009.5 35.6 284.0 450.0 365.0 22.0 0.1 548.5 4 000.0 620.0 75 040:0
1099 kg chemical fertilizer and 22 t manure were used in greenhouse eggplant production per hectare. The shares of nitrogen fertilizer, phosphorus and potassium were 25.8%, 40.9% and 33.0% respectively, in the total chemical fertilizer used. Electricity and irrigation water used in the eggplant production were 4000 kWh and 620 m3 , respectively. The average eggplant yield was 75 040 kg ha−1 . Energy equivalent of this yield was 60 032 ha−1 . Total energy equivalent of the inputs of the eggplant production was calculated 98:68 GJ per hectare. Diesel accounts for one out of three of the total input energy used in the production. This was followed by nitrogen fertilizer (19.03%), electricity (14.59%) and chemicals (13.43%). Output–input energy ratio for greenhouse eggplant production was 0.61. 3.5. Energy use in greenhouse pepper production Table 6 represents the values for pepper production in greenhouses. As this table show about 164:0 kg chemicals, 357 kg nitrogen, 360 kg phosphorus and 310 kg potassium were used in pepper production per hectare. The use of human power and machinery power were 1409.1 and 21:8 h ha−1 , respectively. The average pepper yield was 100 tha−1 . Energy equivalent of this yield was calculated as 80 GJ per unit area. The results showed that total energy
Total energy equivalent (MJ)
%
13 257.2 2 321.9 2 306.9 18 783.8 5 598.0 4 069.8 6 668.2 0.1 30 886.0 14 400.0 390.6 98 682:5 60 032:0 0:61
13.43 2.35 2.34 19.03 5.67 4.12 6.76 0.00 31.30 14.59 0.40 100:00
equivalents of the inputs used in the pepper production were 80:25 GJ ha−1 . Nitrogen fertilizer had the biggest share with 24.42% of total energy input used in the production. This was followed by agro-chemicals (20.68%), diesel-oil (20.39%) and electricity (11.21%). Output–input energy ratio for greenhouse pepper production was 0.99. 4. Discussion Among the crops investigated, tomato had the highest energy output–input ratio. The lowest ratio was for eggplant production. Pepper production had almost equal energy output–input ratio. The higher energy output–input ratio for tomato production indicated a higher yield per m2 from the other crops. Eggplant and pepper production were ine8cient in terms of input utilization and yield. These energy ratios are quite low in general when compared to the values obtained for open-7eld agriculture (Table 7). Despite more intensive use of inputs in greenhouse production in comparison with the open-7eld crop production, such intense use of inputs was not accompanied with the satisfying yield increase. This indicated that inputs used were far beyond the requirements of plants in terms of application time and the amount used. This may also imply that seeds or
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B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
Table 6 Energy inputs, outputs and the ratio in greenhouse pepper production Inputs (unit)
Quantity per unit area (ha)
Chemicals (kg) Human labour (h) Machinery (h) Nitrogen (kg) Phosphate (kg) Potassium (kg) Manure (tonnes) Seed (kg) Diesel-oil (l) Electricity (kW h) Water for irrigation (m3 ) Total input energy (MJ ) Yield (kg ha−1 ) Energy output–input Ratio
164.0 1 409.1 21.8 357.0 360.0 310.0 5.5 0.1 290.6 2 500.0 670.0 100 000:0
Table 7 Summary of some other studies conducted for open-7eld agriculture
Yaldiz [10]
Singh [14]
MAFF [19]
Crops
Energy ratio (MJ)
Sugarbeet Maize Chickpea Soybean SunOower Barkley Wheat Cotton Beans Potatoes
5.04 3.66 3.33 2.12 2.91 2.41 2.59 6.45 1.85 2.74
Mustard Crop
1.75
Wheat Wheat
2.51 1.38
Organic vegetable Leeks Calabrese Onions Potatoes Cabbage Carrots
5.31 3.11 0.81 2.41 2.15 3.21 4.80
Remarks
Turkey
Gurgoan District/India Jhajjar/ India Karnal/ India
UK
Total energy equivalent (MJ)
% in total
16 596.8 3 240.9 1 416.0 23 611.9 4 478.4 3 456.5 1 667.1 0.1 16 363.6 9 000.0 422.1 80 253:4 80 000:0 0:99
20.68 4.04 1.76 29.42 5.58 4.31 2.08 0.00 20.39 11.21 0.53 100:00
seedlings used and the cultural practices in the production stages were not of high quality. Diesel-oil had the highest share among the inputs, due to the fact that the greenhouse soil was usually tilled by ploughs, and the tractor power used was well over the necessary level in such small areas. Therefore, diesel-oil consumption is purely almost for soil tillage. This suggests that less energy consuming machinery in soil tillaging, such as chisel, and much smaller tractors, should be used to decrease fuel consumption in greenhouses. In Turkey greenhouses are heated only for frost prevention. The second most important input was nitrogen. Again, the excessive or ine8cient use of nitrogen has implications, in comparison with the optimum requirements of the plants, as indicated by the 7nal yield per hectare. This excessive use suggests that the nitrogen not consumed by the plants pollutes the underground water and the environment as suggested by Kaplan et al. [18]. Agrochemical use for pest and disease control in greenhouses is at signi7ciant levels in Turkey, due to the mainly very high relative humidity of air and poor ventilation in greenhouses. The timing of chemical applications is a subject that need to be addressed in Turkish greenhouses. Some form of biological control has to be used to reduce the energy inputs from the
B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
chemicals and to protect human and environmental health. A typical greenhouse in Europe yields more than three times the same size greenhouse in Turkey. This is mainly due to more e8cient use of inputs, the use of more productive varieties, and better environmental control. Finally, in the research area, greenhouse operators are still increasing the amount of inputs used in vegetable production. However, the timing of any applications of the inputs is not a signi7cant issue for the Turkish greenhouse producer. This inevitably leads to problems associated with energy use such as global warming, nutrient loading and pesticide pollution, as indicated above. Therefore, there is a need to develop a new policy to be pursued to force producers to use all inputs on time undertake more energy-e8cient practices. There is also a requirement to use high-productivity varieties of crops to increase energy output–input ratios.
[8]
[9] [10]
[11]
[12] [13]
[14]
References [1] Baudoin WO. Protected cultivation in the Mediterranean region. Acta Horticulture 1999;486:23–30. [2] Mugnoza GZ. Greenhouse functional and structural aspects: a European network project. Paper Presented at the World Conference on Horticultural Research, Rome, Italy, 17–20 June 1998. [3] Sevgican A. Protected cultivation in Turkey. Acta Horticulture 1999;486:31–4. [4] Ministry of Agriculture and Rural AKairs. Report of Antalya Province, 2000 (in Turkish). [5] Ram RA, Raghuvanshi NK, Arya SV. Study on energy cost requirements for wheat cultivation. ISAE. XVII. Annual Convention. Paper No: 80-105, New Delhi, 1980. [6] Pathak B, Binning AS. Energy use pattern and potential for energy saving in rice–wheat cultivation. Agric. Energy 1985;4:271–8. [7] Yadav RN, Singh RKP, Prasad S. An economic analysis of energy requirements in the production of potato crop in Bihar
[15]
[16] [17] [18] [19] [20]
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Sharif Block of Nalanda District (Bihar). Economic AKairs 1991;36:112–9. Singh S, Singh G. Energy input crop yield relationship for four major crops of Northern India. Agricultural Mechanization in Asia, Africa and Latin America 1992;23(2):57–61. Thakur CL, Mishra BL. Energy requirements and energy gaps for production of major crops in Madhya Pradesh. Agricultural Situation of India 1993;48:665–89. Yaldiz O, Ozturk HH, Zeren Y, Bascetincelik A. Energy use in 7eld crops of Turkey. 5. International Congress of Agricultural Machinery and Energy, Kusadasi, Turkey, 1993, (in Turkish). Shapouri H, Du8eld JA, Graboski MS. Estimating the net energy balance of corn ethanol. Agricultural Economic Report No 721. US, Department of Agriculture, Economic Research Service, O8ce of Energy, 1995. Baruah DC, Bhattacharya PC. Utilization pattern of human and fuel energy in tea plantation. Journal of Agriculture and Soil Science 1995;8(2):189–92. Singh S, Verma SR, Mittal JP. Energy requirements for production of major crops in India. Agricultural Mechanization in Asia, Africa and Latin America 1997;28(4):13–7. Singh JM. On farm energy use pattern in diKerent cropping systems in Haryana, India. Master of Science, International Institute of Management University of Flensburg, Germany, 2002. Chandra H, De Dipanker, Singh, RS. Spatial variation in energy use pattern for paddy cultivation in India. Proceedings of National Workshop on Energy and Environment Management for Sustainable Development of Agriculture and Agro Industrial Sector, 8–9 July, India, 2001, p. 48–51. Yamane T. Elementary sampling theory. Englewood CliKs, NJ, USA: Prentice-Hall, 1967. DPT. A research on Turkish family structure. General Directorate of Social Planning. Ankara: DPT Publications, 1993 (in Turkish). Kaplan M, Sonmez S, Tokmak S. The nitrate content of well waters in the Kumluca region-Antalya. Turkish Journal of Agriculture & Forestry 1999;23:309–14. MAFF. Energy use in organic farming systems. Ministry of Agriculture, Fisheries and Food, Research and Development Final Project Report 2000. Shrestha DS. Energy use e8ciency indicator for agriculture, 1998. http://www.usaskca/agriculture/caedac/PDF/ mcrae.PDF,10/10/2002.
Biomass and Bioenergy 26 (2004) 89 – 95
An input–output energy analysis in greenhouse vegetable production: a case study for Antalya region of Turkey Burhan Ozkana;∗ , Ahmet Kurklub , Handan Akcaoza a Department
b Department
of Agricultural Economics, Faculty of Agriculture, University of Akdeniz, Antalya 07058, Turkey of Agricultural Machinery, Faculty of Agriculture, University of Akdeniz, Antalya 07059, Turkey
Received 5 January 2003; received in revised form 10 February 2003; accepted 24 April 2003
Abstract The aim of this research was to examine the energy equivalents of inputs and output in greenhouse vegetable production in the Antalya province of Turkey. For this purpose, the data for the production of four greenhouse crops (tomato, cucumber, eggplant and pepper) were collected in eighty-eight greenhouse farms by questionnaire. The results revealed that cucumber production was the most energy intensive of among the four crops investigated. Cucumber production consumed a total of 134:77 GJha−1 followed by tomato with 127:32 GJha−1 . The consumption of energy by eggplants and pepper were 98.68 and 80:25 GJha−1 , respectively. The output–input energy ratio for greenhouse tomato, pepper, cucumber and eggplant were estimated to be 1.26, 0.99, 0.76 and 0.61, respectively. This indicated an intensive use of inputs in greenhouse vegetable production not accompanied by increase in the 7nal product. This can lead to problems associated with these inputs such as global warming, nutrient loading and pesticide pollution. Therefore, there is a need to pursue a new policy to force producers to undertake energy e8cient practices to increase the yield without diminishing natural resources. ? 2003 Elsevier Ltd. All rights reserved. Keywords: Energy equivalent; Energy Use; Input–output; Greenhouses; Vegetables; Antalya
Nomenclature
1. Introduction
n is the required sample size, N the number of holdings in target population, Nh the number of the population in h the strati7ed, Sh2 the variance of h the strati7ed, d the precision where (x − X ), z the reliability coe8cient (01.96 which represent the 95% reliability) and D2 the d2 =z 2 .
1.1. General situation
∗ Corresponding author. Tel.: +90-242-310-2475; fax: +90242-227-4564. E-mail address: [email protected] (B. Ozkan).
Agriculture is an important economic sector in Turkey despite its diminish share over time. It contributed 14% of gross domestic product (GDP) in 2000 and 10.6% of total exports. More than 40% of the total population of the country is engaged in agriculture, and operate 4 million farm holdings. Horticultural production is an important part of the agricultural sector in Turkey and an area for potential export growth. Total vegetable production
0961-9534/04/$ - see front matter ? 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0961-9534(03)00080-1
90
B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
was estimated at over 20 million tonnes produced on 785 000 ha. About 2.7% of total vegetable production was exported fresh, 2.3% was sold to processors, and the rest was consumed fresh. Vegetables are produced both on open 7elds and under cover. Turkish greenhouse production continues to show very rapid expansion as in all Mediterranean countries. In 1999 total greenhouse area was 18 994 ha of which 5264 ha was under glass and 13 730 ha was under plastic. As of 1999, the total undercover area of Turkey was 42 314 ha, i.e. about 10% of the total greenhouse area of Mediterranean countries is about 400 000 ha [1], where about 60 –70% of the European greenhouses are concentrated [2]. Greenhouse production in Turkey began in 1940s in glasshouses built in Antalya province [3], which is still the centre of such production due to the very favourable climatic conditions for protected cultivation. According to 1999 statistics, 81.8% of the glasshouses and 48.5% of the plastic houses of the country were located in Antalya (Table 1). Greenhouse production provides not only income to owners but also many employment opportunities. The vegetables produced most extensively are tomato, cucumber, eggplant and pepper. Vegetable production is mostly carried out as a family business and the technological and productivity levels are very low compared to developed countries. The average size of the greenhouses is around 0.3–0:5 ha. Tomato, cucumber, pepper and eggplant are dominant in greenhouse production, with the share of 90.2% in the total protected area. Among the four crops, tomato production takes the biggest share, of 50.1%. The shares of cucumber, pepper and eggplants
in the total production area are 22.3%, 10.4% and 7.4%, respectively [4]. 1.2. Energy analysis Direct and indirect forms of energy are required for agricultural production. Energy input–output analysis is usually used to evaluate the e8ciency and environmental impacts of the production systems. Some research has been conducted for 7eld-grown plants [5–15]. However, the authors have not come across publication analysing energy input and output in greenhouse vegetable production which is a very energy-intensive sector of the industry. Therefore, there was an immediate need to carry out such an analysis for future steps to be taken for any improvement in greenhouse production systems regarding the energy values of the inputs and the output. On this basis, this study is aimed at preparing an energy audit for greenhouse vegetable production.
2. Material and methods Data were collected from growers in Antalya province producing greenhouse vegetables, by using a face-to-face questionnaire in the production year 2001. The survey was carried out in 128 villages where important undercover production exists. A total of 88 growers was randomly selected from the villages using the strati7ed random sampling method. The greenhouse farms in the sample were strati7ed into two greenhouse size groups, by using the
Table 1 Distribution of protected area of Turkey and Antalya (ha) [4] Protected cultivation
Turkey
Antalya %
The share of Antalya in Turkey (%)
Area
%
Area
Glasshouse (a) Plastic house (b) Greenhouse (a + b) High plastic tunnels Low plastic tunnels
5264 13 730 18 994 4309 19 012
12.4 32.5 44.9 10.2 44.9
4306 6657 10 963 0822 1552
32.3 49.9 82.2 6.2 11.6
81.8 48.5 57.7 19.1 8.2
Total protected area
42 314
100.0
13 337
100.0
31.5
B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
91
Neyman method [16]: ( N h Sh ) n= 2 2 ; N D + Nh Sh2
the inputs to the total energy equivalent of the yield, for each vegetable.
where n is the required sample size, N the number of holdings in target population, Nh the number of the population in h the strati7ed, Sh2 the variance of h the strati7ed, d the precision where (x − X ), z the reliability coe8cient (01.96 which represent the 95% reliability) and D2 the d2 =z 2 . The permissible error in sample population was de7ned to be 5%, and the sample size was calculated to be 88 for 95% reliability. Socio-economic characteristics of the farms were also determined to support the present analysis. The energy equivalents of inputs used in the crop production are illustrated in Table 2. The data on energy use have been taken from a number of sources, as indicated in the table. The sources of mechanical energy used on the selected farms included tractors and diesel oil. The mechanical energy was computed on the basis of total fuel consumption (l ha−1 ) in diKerent operations. The energy consumed was calculated using conversion factors (1 l diesel=56:31 MJ) and expressed in MJha−1 . Energy use in the production of the vegetables investigated was calculated on a m−2 basis. Basic information on energy inputs and crop yields were used to calculate the metabolizable energy. The energy ratio was found by dividing the total energy equivalent of
3. Results
Table 2 Energy equivalents of inputs and outputs in agricultural production Input (Unit)
Energy equivalent, (MJ unit −1 )
Reference
Chemicals (kg) Human power (h) Machinery (h) Nitrogen fertilizer (kg) Phosphorus (kg) Potassium (kg) Manure (tonnes) Seeds (kg) Diesel- oil (l) Electricity (kW h) Water for irrigation (m3 ) Tomato, cucumber, eggplant, pepper
101.2 2.3 64.8 66.14 12.44 11.15 303.1 1.0 56.31 3.6 0.63
Yaldiz [10] Yaldiz [10] Singh [14] Shrestha [20] Shrestha [20] Shrestha [20] Yaldiz [10] Singh [14] Singh [14]
0.80
Yaldiz [10]
3.1. Socioeconomic characteristics of the greenhouse farms The average age of the growers was 53.9 years and the average size of farm family in survey households was 4.94 people, lower than the average (5.4 people) in the rural regions of Turkey [17]. In the research area, average farm size was determined as 4:8 ha which 7.81% of the farm area are used for the production of vegetable crops. 89%, 8.5% and 2.4% of the farm land was owned, rented and shared, respectively. The average number of tractors was 0.82. 3.2. Energy use in greenhouse tomato production The inputs used in tomato production and their energy equivalents, output energy equivalent and energy ratio are illustrated in Table 3. About 98:7 kg pest and disease control chemicals and 976 kg chemical fertilizer were used in greenhouse tomato production on a hectare basis. The shares of nitrogen fertilizer, phosphorus and potassium were 32.8%, 37.2% and 30.0%, respectively, in the total chemical fertilizer used. The use of human power and machinery were 3 248:2 and 46:3 h ha−1 . The total energy equivalent of inputs was calculated as 127:32 GJ ha−1 . Diesel-oil had the highest share, of 32.17%, followed by nitrogen fertilizer (16.62%), manure (16.24%) and electricity (12.44%), respectively. The energy inputs of seeds and water for irrigation were found to be quite low compared to the other inputs used in production. The average yield of tomatoes was found 200 tonnes ha−1 and its energy equivalent was calculated to be 160 GJha−1 . Based on these values, output–input energy ratio for greenhouse tomatoes was 1.26. 3.3. Energy use in greenhouse cucumber production The inputs, used in the cucumber production and their energy equivalents, together with the energy equivalent of the yield were illustrated in Table 4.
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B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
Table 3 Energy inputs, outputs and the ratio in greenhouse tomato production Inputs (unit) Chemicals (kg) Human power (h) Machinery (h) Nitrogen fertilizer (kg) Phosphorus (kg) Potassium (kg) Manure (tonnes) Seeds (kg) Diesel-oil (l) Electricity (kW h) Water for irrigation (m3 ) Total energy input (MJ ) Yield (kg ha−1 ) Energy Output–Input Ratio
Quantity per unit area (ha) 98.7 3 248.2 46.3 320.0 363.0 293.0 68.2 0.1 727.5 4 400.0 700.0 200 000:0
Total energy equivalent (MJ)
%
9 988.4 7 470.9 3 000.2 21 164.8 4 515.7 3 266.9 20 671.4 0.1 40 965.5 15 840.0 441.0 127 324:9 160 000:0 1:26
7.84 5.87 2.36 16.62 3.55 2.57 16.24 0.00 32.17 12.44 0.35 100:00
Total energy equivalent (MJ)
%
13 419.1 7 570.5 4 250.9 19 379.0 4 640.1 4 259.3 13 639.5 0.1 57 464.4 9 720.0 428.4 134 771:3 102 304:0 0:76
9.96 5.62 3.15 14.38 3.44 3.16 10.12 0.00 42.64 7.21 0.32 100:0
Table 4 Energy inputs, outputs and the ratio in greenhouse cucumber production Inputs (unit) Chemicals (kg) Human power (h) Machinery (h) Nitrogen fertilizer (kg) Phosphorus (kg) Potassium (kg) Manure (tonnes) Seeds (kg) Diesel-oil (l) Electricity (kW h) Water for irrigation (m3 ) Total energy input (MJ ) Yield (kg ha−1 ) Energy output–input Ratio
Quantity per unit area (ha) 132.6 3 291.5 65.6 293.0 373.0 382.0 45.0 0.1 1 020.5 2 700.0 680.0 127 880:0
As indicated in the table about 132:6 kg chemicals, 1048 kg chemical fertilizer and 45 t manure were used in greenhouse cucumber production on a hectare basis. The use of human power and machinery were 3 291:5 and 65:6 h ha−1 , respectively. Average cucumber yield was 127 880 kg ha−1 . The total energy input was calculated 134:77 GJ ha−1 . Diesel-oil was the energy input in the total with a share of 42.64%. This was followed by nitrogen
fertilizer (14.38%), manure (10.12%) and chemicals (9.96%). Based on these values output–input energy ratio for greenhouse cucumber was 0.76. 3.4. Energy use in greenhouse eggplant production Table 5 shows the inputs, their energy equivalents, energy equivalent of the yield and the ratio. The research has shown that about 131:0 kg chemicals,
B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
93
Table 5 Energy inputs, outputs and the ratio in greenhouse eggplant production Inputs (unit) Chemicals (kg) Human power (h) Machinery (h) Nitrogen fertilizer (kg) Phosphorus (kg) Potassium (kg) Manure (tonnes) Seeds (kg) Diesel-oil (l) Electricity (kW h) Water for irrigation (m3 ) Total Energy Input (MJ ) Yield (kg ha−1 ) Energy output–input Ratio
Quantity per unit area (ha) 131.0 1 009.5 35.6 284.0 450.0 365.0 22.0 0.1 548.5 4 000.0 620.0 75 040:0
1099 kg chemical fertilizer and 22 t manure were used in greenhouse eggplant production per hectare. The shares of nitrogen fertilizer, phosphorus and potassium were 25.8%, 40.9% and 33.0% respectively, in the total chemical fertilizer used. Electricity and irrigation water used in the eggplant production were 4000 kWh and 620 m3 , respectively. The average eggplant yield was 75 040 kg ha−1 . Energy equivalent of this yield was 60 032 ha−1 . Total energy equivalent of the inputs of the eggplant production was calculated 98:68 GJ per hectare. Diesel accounts for one out of three of the total input energy used in the production. This was followed by nitrogen fertilizer (19.03%), electricity (14.59%) and chemicals (13.43%). Output–input energy ratio for greenhouse eggplant production was 0.61. 3.5. Energy use in greenhouse pepper production Table 6 represents the values for pepper production in greenhouses. As this table show about 164:0 kg chemicals, 357 kg nitrogen, 360 kg phosphorus and 310 kg potassium were used in pepper production per hectare. The use of human power and machinery power were 1409.1 and 21:8 h ha−1 , respectively. The average pepper yield was 100 tha−1 . Energy equivalent of this yield was calculated as 80 GJ per unit area. The results showed that total energy
Total energy equivalent (MJ)
%
13 257.2 2 321.9 2 306.9 18 783.8 5 598.0 4 069.8 6 668.2 0.1 30 886.0 14 400.0 390.6 98 682:5 60 032:0 0:61
13.43 2.35 2.34 19.03 5.67 4.12 6.76 0.00 31.30 14.59 0.40 100:00
equivalents of the inputs used in the pepper production were 80:25 GJ ha−1 . Nitrogen fertilizer had the biggest share with 24.42% of total energy input used in the production. This was followed by agro-chemicals (20.68%), diesel-oil (20.39%) and electricity (11.21%). Output–input energy ratio for greenhouse pepper production was 0.99. 4. Discussion Among the crops investigated, tomato had the highest energy output–input ratio. The lowest ratio was for eggplant production. Pepper production had almost equal energy output–input ratio. The higher energy output–input ratio for tomato production indicated a higher yield per m2 from the other crops. Eggplant and pepper production were ine8cient in terms of input utilization and yield. These energy ratios are quite low in general when compared to the values obtained for open-7eld agriculture (Table 7). Despite more intensive use of inputs in greenhouse production in comparison with the open-7eld crop production, such intense use of inputs was not accompanied with the satisfying yield increase. This indicated that inputs used were far beyond the requirements of plants in terms of application time and the amount used. This may also imply that seeds or
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B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
Table 6 Energy inputs, outputs and the ratio in greenhouse pepper production Inputs (unit)
Quantity per unit area (ha)
Chemicals (kg) Human labour (h) Machinery (h) Nitrogen (kg) Phosphate (kg) Potassium (kg) Manure (tonnes) Seed (kg) Diesel-oil (l) Electricity (kW h) Water for irrigation (m3 ) Total input energy (MJ ) Yield (kg ha−1 ) Energy output–input Ratio
164.0 1 409.1 21.8 357.0 360.0 310.0 5.5 0.1 290.6 2 500.0 670.0 100 000:0
Table 7 Summary of some other studies conducted for open-7eld agriculture
Yaldiz [10]
Singh [14]
MAFF [19]
Crops
Energy ratio (MJ)
Sugarbeet Maize Chickpea Soybean SunOower Barkley Wheat Cotton Beans Potatoes
5.04 3.66 3.33 2.12 2.91 2.41 2.59 6.45 1.85 2.74
Mustard Crop
1.75
Wheat Wheat
2.51 1.38
Organic vegetable Leeks Calabrese Onions Potatoes Cabbage Carrots
5.31 3.11 0.81 2.41 2.15 3.21 4.80
Remarks
Turkey
Gurgoan District/India Jhajjar/ India Karnal/ India
UK
Total energy equivalent (MJ)
% in total
16 596.8 3 240.9 1 416.0 23 611.9 4 478.4 3 456.5 1 667.1 0.1 16 363.6 9 000.0 422.1 80 253:4 80 000:0 0:99
20.68 4.04 1.76 29.42 5.58 4.31 2.08 0.00 20.39 11.21 0.53 100:00
seedlings used and the cultural practices in the production stages were not of high quality. Diesel-oil had the highest share among the inputs, due to the fact that the greenhouse soil was usually tilled by ploughs, and the tractor power used was well over the necessary level in such small areas. Therefore, diesel-oil consumption is purely almost for soil tillage. This suggests that less energy consuming machinery in soil tillaging, such as chisel, and much smaller tractors, should be used to decrease fuel consumption in greenhouses. In Turkey greenhouses are heated only for frost prevention. The second most important input was nitrogen. Again, the excessive or ine8cient use of nitrogen has implications, in comparison with the optimum requirements of the plants, as indicated by the 7nal yield per hectare. This excessive use suggests that the nitrogen not consumed by the plants pollutes the underground water and the environment as suggested by Kaplan et al. [18]. Agrochemical use for pest and disease control in greenhouses is at signi7ciant levels in Turkey, due to the mainly very high relative humidity of air and poor ventilation in greenhouses. The timing of chemical applications is a subject that need to be addressed in Turkish greenhouses. Some form of biological control has to be used to reduce the energy inputs from the
B. Ozkan et al. / Biomass and Bioenergy 26 (2004) 89 – 95
chemicals and to protect human and environmental health. A typical greenhouse in Europe yields more than three times the same size greenhouse in Turkey. This is mainly due to more e8cient use of inputs, the use of more productive varieties, and better environmental control. Finally, in the research area, greenhouse operators are still increasing the amount of inputs used in vegetable production. However, the timing of any applications of the inputs is not a signi7cant issue for the Turkish greenhouse producer. This inevitably leads to problems associated with energy use such as global warming, nutrient loading and pesticide pollution, as indicated above. Therefore, there is a need to develop a new policy to be pursued to force producers to use all inputs on time undertake more energy-e8cient practices. There is also a requirement to use high-productivity varieties of crops to increase energy output–input ratios.
[8]
[9] [10]
[11]
[12] [13]
[14]
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