An Energy Analysis in Greenhouse Tomato Production in Bulgaria

Transcription

1 An Energy Analysis in Greenhouse Tomato Production in Bulgaria Miroslav MIHOV 1, Totka MITOVA 2, Stoyka MASHEVA 1, Vinelina YANKOVA 1 1 Maritsa Vegetable Crops Research Institute, Plovdiv, 3, Bulgaria 2 N. Pushkarov Institute of Soil Science, Sofia, 1, Bulgaria mihovm@gmail.com Abstract: Greenhouse tomato production in Bulgaria is extremely energy intensive. With heated production the energy balance parameters revealed that the tomato production consumed 12.44*1 3 GJ ha -1 and energy intensity is MJ kg -1. However, the majority of producers grow tomatoes in greenhouses without heating. Where the total energy input decreases to GJ with the energy intensity being 1.58 MJ kg -1. The aim of this research is to improve the energy effectiveness of the tomato production by using some Good Agricultural Practices in greenhouse production. Various trials were conducted with reduced energy inputs, the results of which show that it is possible to decrease the total consumption by 25.97% and improve the energy balance. By using a combined machine for soil preparation, a new method for soil disinfection, new plant protection products and new nutrition strategies the energy intensity can be decreased to.89 MJ kg -1 thus increasing the output-input ratio from.51 to.9. Key words: Tomato production, greenhouses, diesel oil, machinery, plant protection products, solarization, fertilizers, bioproducts, energy consumption, energy equivalent, energy ratio. Nomenclature: GAP good agricultural practices; GPPP good plant protection practices; a. i. active ingredient; PPP plant protection products; HPT human power of technicians; NNS new nutrition strategy INTRODUCTION Greenhouse tomato production in Bulgaria is extremely energy intensive. There are more than ha greenhouses with greenhouse vegetable production coming up to 9 t, which constitutes 7.6% of the total vegetable production in the country. Even though this indicator shows an increase [Ministry of agriculture and food, 27] greenhouse vegetable production faces a number of problems, some of the more important ones are high energy consumption, low yield and high cost of the production [Masheva and Simidchiev, 24]. Tomatoes are the main culture produced in greenhouses due to the fact that the climate, even in the winter months in the larger part of the country are mild and suitable for growing these plants. It is also due to the large demand and consumption of tomatoes all year round both in the country and for export. The economic environment and the energy crisis in the 197s enforced winter-spring and autumnwinter tomato production, or when there is a lack of fuel - production with emergency heating and production without heating. Preliminary research carried out by the authors show that the economic efficiency is higher in winter-spring production and production with energy heating [Masheva and Simidchiev, 24; Mihov and Mitova, 28]. The total energy consumption for the production of 1 ha of tomatoes in winter-spring production in greenhouses is 12.44*1 3 GJ, however the energy intensity is MJ kg -1, which makes it extremely high energy intensive production. The energy balance of the production can be slightly improved by using natural gas for heating, which reduces the total energy consumption to 19.64%. The total energy consumption for the production of 1 ha of tomatoes in production without heating is GJ and the energy intensity is 1.58 MJ kg -1. Greenhouse 446

2 production is based on non-renewable energy and when using heating in the winter it amounts to 99.5% of the total energy used in the production [Mihov and Mitova, 28]. In order to improve the energy effectiveness of the greenhouse tomato production, the above mentioned numbers of energy consumption can be influenced. This could be achieved by using contemporary machinery and improving the growing technology towards optimizing the quantity of plant protection products as well as the introduction of new strategies for maintaining the plant nutrition. The aim of this research is to improve the energy effectiveness of the tomato production by using Good Agricultural Practices in greenhouse production. MATERIAL and METHODS The research was carried out in Venlo type greenhouses with 3.2 m width of the spans and a scheme of growing cm. The energy inputs and outputs were converted from physical to energy unit measures by using their energy equivalents shown in table 1. They were used by Hatirli et al. (26) and Ozkan et al. (24) in the evaluation of the energy inputs and outputs for greenhouse tomato production in Turkey. The energy equivalent of the tomato seedlings and the Lumbrical (dry matter content) was determined by the authors by using a calorimeter. Energy consumption for water for irrigation (m 3 ), electricity (kwh), tomato seedlings (kg), polyethylene products (kg) etc. are shown under Consumption/Others. soil cultivation was used in order to reduce the inputs. The perspective machinery complex consists of a combined machine (figure 1) for plowing and milling spitmachine with a harrow with 1,5 m working width (Holland) and a soil shaping machine with 1,5 m working width (experimental prototype) aggregated with a small-sized tractor kw. The relative part of energy inputs for PPP comes to 1.8%, which includes 13 kg Bazamidе granulate for chemical soil disinfection, 18 kg a. i. fungicides and 9.4 kg a. i. insecticides. These are applied together in 14 treatments. GPPPs in greenhouse production (an integrated method for soil disinfection solarization (figure 2) followed by the application of a bioproducts with a fungicide effect and optimization the application of some pesticides) are used for achieving the aims of the research. Figure 2. Polyethylenes cover for solarization The relative part of energy inputs for fertilization comes to 21.24% for mineral fertilizers and 15.42% for manure. These include 396 kg a. i. nitrogen, 138 kg a. i. phosphorus, 732 kg a. i. potassium, 2 kg a. i. magnesium and t manure. In order to reduce the inputs for fertilization, the energy inputs are optimized by replacing the manure with a biofertilizer Lumbrical and by determining the need for chemical fertilizers through a soil analysis. Figure 1. The combined machine in action Production without energy is used for control. Data obtained through interviews and from specialized literature show that the relative part of energy inputs for diesel oil and machinery are 14.% of the total energy consumption. Perspective machine complex for RESEARCH RESULTS The trials for reducing the energy inputs for diesel oil and machinery show that fuel can be saved when using a combined machine that performs two operations together plowing and milling. With PPP, fertilizers and manure inputs being the same as the control ones, the quantity of fuel, as well as its energy equivalent reduces by 14.33%, the energy inputs for machinery reduce by 19.64% and the quantity of human power of technicians reduces by 8.67% (figure 447

3 3). As a result the output-input ratio increases by 2.37% and the total energy inputs for production increase by 2.34%. Control Combined machines 2 PPP Fertilizers Manure Diesel Machinery HPT Figure 3. Reducing the energy inputs by using a combined machine The application of new methods and plant protection products also has a positive effect on the total energy inputs for greenhouse tomato production. With the fertilizers, manure and diesel oil quantities being the same as the control ones, the energy inputs for soil disinfection and plant protection during vegetation reduce by.68% and the quantity of human power of technicians reduces by 27.9% (figure 4). As a result, with the energy output being the same as the control output, the output-input ratio increases by 6.51% and the total energy inputs for production increase by 6.21%. Control GPPP (figure 5). As a result the output-input increases considerably by 57.%. Another major reason for the good result is the 31.5% increase of the energy outputs with the yield. Table 1 presents the results from the application of the good agricultural practices in tomato greenhouse production without heating. The energy effective production is the result of the combination of perspective machine complex, new PPP and a new scheme of plant protection, the application of Lumbrical as well as the determination of the parameters of conventional fertilization based on soil analysis. 2 PPP Fertilizers Manure / Lumbrical Control NNS Diesel Machinery HPT Figure 5. Reducing the energy inputs by applying new nutrition strategy The total tomato production energy inputs are GJ ha -1. These inputs are 25.97% less than the control ones. The energy outputs obtained with tomato yield increase and come up to 15.2 GJ ha -1. These results have a positive impact on the energy intensity of the production, which reduces from 1.57 MJ kg -1 to.89 MJ kg -1 (56.7%) in the energy effective production. The output-input ratio increases by 77.62% and comes to.9. 2 PPP Fertilizers Manure Diesel HPT Figure 4. Reducing the energy inputs by applying Good plant protection practices The results from the application of new nutrition strategies in greenhouse tomato growing show that with PPP inputs being the same with the control ones the quantity of a. i. of the fertilizers decreases by 66.58%, the diesel oil inputs reduce by 12.87%, the inputs for machinery reduce by 1.19% and the inputs for human power of technician reduces by 6.54% DISCUSSION The perspective machine complex for soil preparation in greenhouse tomato production allows for optimization of the direct production costs and the costs of human power. The effect of its application, however, is not so great due to the fact that the energy inputs for soil preparation take up to 8.9% of the total production energy inputs for tomato growing i.e. the soil preparation have a small energy share and a considerable improvement of the energy balance cannot be expected. 448

4 Table 1. Structure of energy consumption Consuption Energy equivqlent, MJ unit -1 quantity, unit ha -1 Control total energy equivalent, MJ ha -1 % Energy effective production quantity, unit ha -1 total energy equivalent, MJ ha -1 % PPP (a.i.), kg fungicides insecticides Fertilizers (a.i.), kg nitrogen (N) phosphorus (P) potassium (K) magnesium (Mg) Manure, t Lumbrical, kg Diesel, kg Human power, h incl. technicians Machinery, h incl. soil preparation Others Total energy inputs, MJ Total energy outputs, MJ Energy intensity, MJ kg Energy output-input ratio.51.9 The integrated method for soil disinfection through solarization [Neshev and Mladenov, 2] makes use of the renewable energy of the sun and the use of 1 L biofungicide Thrihodermin every two years ( MJ per year). In comparison with the applied chemical fumigant Bazamidе granulate in the control (119 MJ per year), the needed quantity of energy inputs for soil disinfection reduces by 61.54%. The application of this bioproducts also has an environmental impact. The application of the PPP allows for the optimization of the plant protection scheme. The scheme includes products from various chemical groups, with the view of rotating application; products based on new active ingredients and on a combination of two such active ingredients that are more effective against a number of pathogens etc. The use of products with a wide action spectrum against two or more enemies that can often be found at the same time is another possibility for reducing the number of treatments. The discussion above allows the authors to optimize the plant protection scheme thus reducing the total quantity of active ingredients to 4.3 kg a. i. fungicides and 6.2 kg a. i. insecticides that are applied in combination in 7 treatments. The optimization of the plant protection scheme results in the reduction of the fungicides energy inputs by 76.11% and a reduction of the insecticides energy inputs by 55.32%. Due to the decrease in the treatments from 14 to 7 the total energy equivalent of human power of technicians decreases. The use of novel biofertilizers obtained on the basis of useful microorganisms or biofertilizers with high content of organic matter leads to a considerable 449

5 increase in the tomato yield. The increase in the early yield is 18.5% and the increase in the total yield is 31.5%. Biofertilizers also improve the economic quality of the production [Kute et al., 1997; Barkart et al., 1998 and Tringovska and Kanazirska, 28]. In order to optimize the energy input for plant nutrition, the manure ( MJ ha -1 ) is replaced by Lumbrical kg dry matter content (2.85 MJ ha -1 ). The needed quantity of fertilizers determined through an agrochemical analysis includes kg a. i. nitrogen; 69. kg a. i. phosphorus, 366 kg a. i. potassium and kg a. i. magnesium. The results from the application of these new strategies for plant nutrition in greenhouse tomato production show that the total quantity of the used chemical fertilizers can be reduced from kg to 65.5 kg (in active ingredients). The total energy equivalent of the fertilizers can thus be increased by 66.58%. The substitution of manure with biofertilizer Lumbrical does not have a considerable energy impact the energy saving comes to 4.98%. The application of considerable lower quantities of products for improving the soil fertility in greenhouses leads to a decrease in the energy inputs for diesel oil by MJ ha -1. The increase in the yield, its harvesting and transportation to processing centres also has an impact on the energy inputs for diesel oil, machinery and human power.the new distribution of the relative energy share of energy inputs (table 1) shows that the effective production energy inputs for diesel oil decrease by 46.82%, the energy inputs for chemical fertilizers decrease by 53.95% and the inputs for diesel oil and machinery decrease by 1.% and 14.49%. These results show that energy input for chemical products are reduced and the positive impact on consumer health as well as the environment is improved. CONCLUSIONS The research proved that using a combined machine for soil cultivation, solarization for soil disinfection, an optimized scheme for plant protection and a new nutrition strategy can result in a 25.97% decrease in the total energy input for greenhouse tomato production without heating and a 31.5% increase in the energy outputs. The energy outputs obtained with tomato yield increase and come up to 15.2 GJ ha -1, which results in decrease of the energy intensity of up to,89 MJ kg -1 and an increase in the output-input ratio from 5.1 to.9. The energy input for chemical pollutants are reduced by 46,82% and 53.95% for pesticides and synthetic fertilizers respectively and have a positive impact on consumer health as well as the environment is improved. REFERENCES Barkart M. A. S., S. M. Gabr, Effect of Different Biofertilizer Types and Nitrogen Fertilizer Levels on Tomato Plants. Alexandria Journal of Agricultural research. 43 (1): Hatirli S., B. Ozkan, C. Fert, 26. Energy Inputs and Crop Yield Relationship in Greenhouse Tomato Production. Renewable Energy, 31, Kute S., B. Patel, R. Maheshwari, P. Chaturvedi, Bio-fertilizers. The GSFC Approach. Bio-enegy for Rural Energisation Masheva S., H. Simidchiev, 24. Subject: Greenhouse Crop Development in Bulgaria. 21, First Coordinating Meeting of FAO Regional Working Group on Greenhouse Crop Production in the South East European Countries. Budapest, 2-22 October 24. Mihov, M., T. Mitova, 28. Analysis of the Energy Consumptson in Greenhouse Tomato Production of Different Directions of Production. Agricultural Engineering, Volume XLV, (1): 2-8. [Bulgarian with English summary] Mihov, M., T. Mitova, S. Masheva, 27. Greenhouse Vegetable Production in the New Energy Policy Conditions. Proceedings of II -nd International Symposium Ecological Approaches Towards the Production of Safety Food, Plovdiv, October 27, [Bulgarian with English summary] Ministry of Agriculture and Food, 27. Subject: Bulletin 14. /Agrostatistika/agrostatistika.htm Neshev, G., M. Mladenov, 2. Solarizatsiya na pochvata nov metod za unistozhavane na vreditelite v neya. (Solarization a new method to destroy the pests in it), Plant Protection, (7): [Bulgarian] Ozkan B., A. Kurklu, H. Akcaoz, 24. An Input-output Energy Analysis in Greenhouse Vegetable Production: a Case Study for Antaliya Region of Turkey. Biomass & Bioenergy, 26, Tringovska, I., V. Kanazirska, 28. Influence of Bioproducts and the Method of their Application on Greenhouse Tomato Production Productivity. Plant Science, Volume XLV, (2): 2-8. [Bulgarian with English summary] 45