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Energy Potential of Greenhouse Plant Residue: The Cases of Turkey and Poland
The search for waste management opportunities is crucial for achieving environmentally friendly waste practices and ensuring the country’s energy security. This research aimed to valorize biomass and waste generated in greenhouses and to analyze the potential for electricity production from this waste. The analyses compared the situations in Turkey and Poland, where greenhouse production of vegetables is developing and constitutes an important link in agricultural activities, despite differences in climatic conditions. The cultivation of vegetables and flowers under cover is rapidly expanding in both countries and, with changing climatic conditions, is expected to shape the future of agriculture. In addition to estimating the energy that can be obtained, the study also evaluated the economic benefits of such a solution and the volume of avoided CO2 emissions from fossil fuels. The issue of utilizing these wastes is significant because current methods of their management do not lead to energy production, so their considerable energy potential is wasted, as highlighted in this study. Moreover, there is a lack of similar studies in the literature. The plant species chosen as materials in this study were tomatoes, peppers, eggplant, watermelon, and melon in the case of Turkey. For Poland, the analysis was conducted for tomatoes and greenhouse cucumbers. These crops represent the largest cultivated areas under cover in the respective countries. Results indicated that the average yearly amount of vegetable residue is approximately 463 thousand Mg in Turkey, and 77 thousand Mg in Poland. The estimated annual electricity potential is 430 GWh in Turkey and 80 GWh in Poland. Considering the efficiency of power generation in a typical power plant, the real amount of electricity to be obtained is 0.46 MWh per Mg of waste in Turkey and 0.52 MWh in Poland.
The Benefits of Green Roofs and Possibilities for Their Application in Antalya, Turkey
Rapid population growth, urbanization, and industrialization have many negative environmental effects. These adverse effects are felt more in urban areas than in rural areas. Considering the high rate of urban development, the idea that green roof structures can be used on rooftops is important in reducing the current negative effects. In addition, water retention on these roof areas can be helpful in the face of drought periods. In this study, the amount of water that can be retained on a 100 m2 roof area in Antalya Province, Turkey was calculated. As a result, it was determined that August is the month when the least water can be retained due to rainfall. It was calculated that between 0.168 m3 and 0.363 m3 of water can be retained in August. Furthermore, the month in which the most water can be retained due to rainfall is December, and the amounts of water that can be retained are between 5.762 m3 and 21.640 m3. These calculated values are anticipated to be important in understanding how much water can be retained in the planned green roofs. In addition, it has been determined that the energy savings that can be made for heating purposes in a 100 m2 green roof area can be between 3900 kWh and 11,250 kWh.
The Effect of Drip Irrigation and Nitrogen Levels on the Oil and Fatty Acid Composition of Sesame and Its Economic Analysis
One of the oldest oilseed crops is sesame, which is mainly cultivated due to its valuable oleic/linolenic fatty acid ratio. The application of precise irrigation and fertilisation is crucial to ensure the continuity and productivity of sesame production, especially in arid and semi-arid regions. This study aimed to determine the effect of drip irrigation and nitrogen levels on sesame’s oil and fatty acid composition. For this purpose, four nitrogen doses (N0: 0 kg ha−1, N30: 30 kg ha−1, N60: 60 kg ha−1 and N90: 90 kg ha−1) and three different irrigation water levels (I50, I75 and I100, which correspond to 50, 75 and 100% evaporation levels from the evaporation of the Class A pan) were applied. The highest oleic acid content (43.06%) was obtained for the I75N90 treatment. In the case of linoleic fatty acid, the greatest value (43.66%) was for I50N0 treatment. The effects of irrigation and nitrogen doses on oleic acid and linoleic acid content were inverse of each other. An increase in applied irrigation water increased the linoleic acid content. However, it caused a decrease in oleic acid content. Increasing the nitrogen dose increased the oleic acid content and caused a decrease in linoleic acid content. Furthermore, this study showed that the I50N60 treatment (50% Epan and a rate of 60 kg N ha−1) is the most effective for achieving high grain and oil yields in sesame cultivation. The results obtained provide practical guidance for farmers in sesame cultivation.
Assessment of the Crop Water Stress Index for Green Pepper Cultivation Under Different Irrigation Levels
The objective of this study was to evaluate the effects of different water levels on yield, morphological, and quality parameters, as well as the crop water stress index (CWSI), for pepper plants under a high tunnel greenhouse in a semi-arid region. For this purpose, the irrigation schedule used in this study includes 120%, 100%, 80%, and 60% (I120, I100, I80, and I60) of evaporation monitored gravimetrically. In this study, increasing irrigation levels (I100 and I120) resulted in increased stem diameter, plant height, fruit number, leaf number, and leaf area values. However, these values decreased as the water level dropped (I60 and I80). At the same time, increased irrigation resulted in improvements in fruit width, length, and weight, as well as a decrease in TSS values. While total yield and marketable yield values increased at the I120 water level, TWUE and MWUE were the highest at the I100 water level. I80 and I120 water levels were statistically in the same group. It was found that the application of I100 water level in the high tunnel greenhouse is the appropriate irrigation level in terms of morphology and quality parameters. However, in places with water scarcity, a moderate water deficit (I80) can be adopted instead of full (I100) or excessive irrigation (I120) in pepper cultivation in terms of water conservation. The experimental results reveal significant correlations between the parameters of green pepper yield and the CWSI. Therefore, a mean CWSI of 0.16 is recommended for irrigation level I100 for higher-quality yields. A mean CWSI of 0.22 is recommended for irrigation level I80 in areas where water is scarce. While increasing the CWSI values decreased the values of crop water consumption, leaf area index, total yield, marketable yield, total water use efficiency, and marketable water use efficiency, decreasing the CWSI increased these values. This study concluded that the CWSI can be effectively utilised in irrigation time planning under semi-arid climate conditions. With the advancement of technology, determining the CWSI using remote sensing-based methods and integrating it into greenhouse automation systems will become increasingly important in determining irrigation times.
Determination of Performance of Different Pad Materials and Energy Consumption Values of Direct Evaporative Cooler
The purpose of this study is to determine the performances of luffa and greenhouse shading netting (which can be used as alternatives to commercial cellulose pads, that are popular for cooling greenhouses), the contribution of external shading to the evaporative cooling performance, and the energy consumption of the direct evaporative cooler. In this experiment, eight different applications were evaluated: natural ventilation (NV), natural ventilation combined with external shading net (NV + ESN), cellulose pad (CP), cellulose pad combined with external shading net (CP + ESN), luffa pad (LP), luffa pad combined with external shading net (LP + ESN), shading net pad (SNP), and shading net pad combined with external shading net (SNP + ESN). The cooling efficiencies of CP, CP + ESN, LP, LP + ESN, SNP, and SNP + ESN were found to be 37.6%, 45.0%, 38.9%, 41.2%, 24.4%, 29.1%, respectively. Moreover, their cooling capacities were 2.6 kW, 3.0 kW, 2.8 kW, 3.0 kW, 1.7 kW, 2.0 kW, respectively. The system water consumption values were 2.9, 3.1, 2.8, 3.2, 2.4, 2.4 l h−1, respectively. The performance coefficients of the system were determined to be 10.2, 12.1, 11.3, 11.9, 6.6, 7.8. The system’s electricity consumption per unit area was 0.15 kWh m−2. As a result of the study, it was determined that commercially used cellulose pads have advantages over luffa and shading net materials. However, luffa pads can be a good alternative to cellulose pads, considering their local availability, initial cost, cooling efficiency, and capacity.
Energy Efficiency in Greenhouses and Comparison of Energy Sources Used for Heating
Sustainability in greenhouse farming, one of the areas where the most energy is needed in the agricultural sector, can be achieved by increasing energy efficiency. Due to increasing energy costs in Türkiye and worldwide, increasing energy efficiency in greenhouses is seen as possible using renewable energy sources that do not produce waste instead of fossil energy sources. This study determined the heat-energy demand in the provinces of Türkiye with continental (Kırşehir and Kütahya) and Mediterranean (Antalya and Mersin) climates. For this purpose, the heat-energy requirement was calculated for greenhouse types with three different insulation properties (S-1: roof and side walls polyethylene, S-2: roof polyethylene, side walls polycarbonate, and S-3: roof polyethylene, side walls polycarbonate, and thermal curtain). Then, the amount and cost of fossil (coal, fuel oil, and natural gas) and renewable energy sources (geothermal and biogas) to be used in obtaining this energy, the heating cost for unit tomato yield, and the amount of carbon dioxide (CO2) released into the atmosphere were compared. According to the results obtained, the highest heat-energy requirement was 356.5 kWh m−2 year−1 in the S-1 greenhouse in the Kütahya province, and the lowest was 46.3 kWh m−2 year−1 in the S-3 greenhouse in the Mersin province. Depending on energy conservation, 6% of energy savings can be achieved in S-2 and 29% in S-3 compared to S-1. The highest heating cost for producing one kilogram of tomatoes was 0.70 USD kg−1 in fuel oil and Kütahya province (S-1). The lowest was calculated as 0.06 USD kg−1 in geothermally heated greenhouses in Kırşehir and Kütahya provinces (S-3). The highest CO2 to be released into the atmosphere with fuels was equal to 253.1 kg m−2 year−1 in coal fuel in Kütahya province (S-1). The lowest was calculated as 1.1 kg m−2 year−1 in geothermally heated greenhouses in Kırşehir and Kütahya provinces (S-3). The results of this research can be used to develop feasibility studies for greenhouse companies, greenhouse sector policies, policymakers, environmental protection, and taking precautions against the climate crisis.
Use of Rainwater Harvesting from Roofs for Irrigation Purposes in Hydroponic Greenhouse Enterprises
This study was conducted to determine the irrigation water demand due to solar radiation in high-tech greenhouses using hydroponic systems in Turkey’s Mediterranean and continental climates, and to determine the annual water consumption and storage capacity with harvested rainwater. Intensive greenhouse cultivation and the recent increase in modern greenhouse cultivation were important factors in selecting the provinces for the study. The chosen provinces were Antalya and Adana, with a Mediterranean climate, and Afyonkarahisar and Kırşehir, with a continental climate. In this research, depending on the production period, the amount of water consumed per unit of area in greenhouses in Antalya, which has a Mediterranean climate, was determined to be 1173.52 L m−2 per yr−1, and in Adana, it was 1109.18 L m−2 per yr−1. In the provinces of Afyonkarahisar and Kırşehir, where a continental climate prevails, water consumption was calculated to be 1479.11 L m−2 per yr−1 and 1370.77 L m−2 per yr−1, respectively. Storage volumes for the provinces of Antalya, Adana, Afyonkarahisar and Kırşehir were found to be 438.39 L m−2, 122.71 L m−2, 42.12 L m−2 and 43.65 L m−2, respectively. For the provinces of Antalya, Adana, Afyonkarahisar and Kırşehir, the rates of rainwater harvesting and meeting plants’ water consumption were calculated to be 80.79%, 54.27%, 27.47% and 25.16%, respectively. In addition, the amount of water fee savings that could be achieved by rainwater harvesting was calculated to be USD 901.3 per yr−1 for Antalya, USD 835.3 per yr−1 for Adana, USD 247.6 per yr−1 for Afyonkarahisar and USD 210.2 per yr−1 for Kırşehir. As a result, rainwater harvesting will not only provide economic gain to enterprises but will also be important in reducing the negative effects of irregular rainfall regimes caused by climate change on underground and surface water resources. It was also concluded that enterprises should focus on popularizing rainwater harvesting.