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The Role of Antitranspirants in Mitigating Drought Stress in Plants of the Grass Family (Poaceae) - A Review
One of the biggest problems facing agriculture is the occurrence of droughts. Due to ongoing climate change, many regions of the world are exposed to increasingly frequent and prolonged water shortages. The situation may significantly reduce production and the quality of many crops in the Poaceae family, including crucial cereals. Therefore, it is important to find solutions that can help adapt plants to the drought phenomenon and reduce its negative effects. One measure that could potentially improve the condition of plants and help them survive under water deficit conditions is the use of antitranspirants (AT), which are products that reduce transpiration. Antitranspirants are divided into three groups: film-forming, metabolic, and reflective types. This review aimed to the current state of knowledge on the effects of selected AT applications on Poaceae plants under drought conditions. It demonstrated that AT, in many cases, mitigates the negative effects of drought on crops such as maize, wheat, or rice, which are crucial for global food security. Furthermore, AT often improved growth and yield parameters. These results are particularly relevant for countries that are important cereals producers and are more vulnerable to droughts in the future. However, it should be noted that the results obtained often depend on several factors, such as plant species, environment, type of antitranspirant, and applied dose. Therefore, it is advisable to measure further the effects of AT on plants under drought-stress conditions.
The effects of high temperature and low humidity on crop water stress index of seed pumpkin plants (Cucurbita pepo L.) in semi-arid climate conditions
This study aimed to evaluate the effects of high temperature and low humidity on the crop water stress index (CWSI) of seed pumpkin plants grown under semi-arid climate conditions to determine the optimum irrigation time. This research unveils the critical impact of high temperature and low humidity on seed pumpkin growth, emphasizing the vital role of the CWSI in optimizing irrigation strategies and seed yield. Moreover, the relationship between CWSI, physiological parameters, and seed yield of the pumpkin was investigated. The mean CWSI values in the I70 (0.40) and I35 (0.56) treatments were 42% and 100% higher, respectively than those in the full irrigation (I100) treatment (0.28). While the I70 treatment showed manageable water stress with minimal impact, the I35 treatment experienced severe stress, significantly reducing crop growth and yield. The mean seed yield (SY) in the I70 treatment increased to 1245.2 kg ha–1 compared to I35 (903.3 kg ha–1) but remained lower than I100 (1339.3 kg ha–1). The CWSI had negative correlations (p ≤ 0.01) with seed yield, chlorophyll content, and leaf area index, while it had positive correlations with water use efficiency and irrigation water use efficiency (p ≤ 0.01). This study showed that pumpkins could be grown successfully at 30% water deficit conditions, and a water deficit higher than 30% may cause a significant seed yield loss in semi-arid climate conditions. In addition, the results highlight the importance of optimal irrigation and CWSI monitoring for informed irrigation decisions and sustainable agricultural practices. Therefore, moderate water deficit (I70) can be adopted in pumpkin cultivation as an alternative to full irrigation.
Effect of Sulphur/Zinc Fertilizer Application on Selected Tomato Parameters in Poland, Spain and Italy
Modern, technologically advanced fertilizers that increase the efficiency of the plant’s use of macro and microelements while reducing the doses used are one of the most important elements of sustainable plant production. Current European Union policy, especially the from-farm-to-fork strategy, which is part of the European Green Deal and sustainable agriculture, requires producers to seek new solutions that will ensure higher yields while reducing the number and volume of fertilizers and pesticides introduced into the environment. The aim of conducted research was to determine the effect of the application of Techno Z (sulphur 67% + zinc 14%), an advanced microgranular sulphur/zinc fertilizer with patented ORT technology on greenhouse-grown tomato, one of the most popular vegetables grown worldwide. Consumption is constantly growing, and demand is much higher in many countries than domestic production. Therefore, measures aimed at increasing yields, such as more effective, sustainable fertilization, are extremely important.
Calculation of the Potential Biogas and Electricity Values of Animal Wastes: Turkey and Poland Case
This research aimed to analyze the potential amount of electrical energy from biogas energy obtained from animal wastes in Turkey and Poland. Animal waste values were calculated by taking into account the recommended literature values. In determining the biomass energy potential of livestock enterprises in Turkey and Poland, FAO’s 2012–2021 data were taken into account. The animal breeds selected as material in this study were cattle, goat, sheep, chicken, duck, goose, turkey, horse, pig, mule and donkey. Considering 10-year calculations, the potential amount of biogas energy that can be obtained from animal wastes for Turkey is 28,845,975 GJ, which is equivalent to 8,105,058 MWh of electrical energy. In Poland, the potential amount of biogas energy that can be generated from animal waste is 13,999,612 GJ, which is equivalent to 3,902,020 MWh of electricity. Moreover, it is estimated that the percentage of the potential amount of electricity to be obtained in 2021 to cover the amount of electricity consumed is 0.303% for Turkey and 0.392% for Poland. For 2021, the amount of economic gains that can be from electricity obtained was also calculated, and it was determined that this value can be 78,650,302 Euro for Turkey and 62,182,435 Euro for Poland. At the same time, it was calculated that the electricity needs of 406,170 houses in Turkey and 171,958 houses in Poland can be met in 2021. As a result, it is thought that the potential electricity to be obtained will contribute to determining energy gains and investment plans for biogas plants.
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.
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.
Monitoring meteorological drought by different drought indices (SPI, RDI, and DI) using drought indices calculator (DrinC) – A case study from Isparta district, a semi-arid Mediterranean region in Türkiye
Description of the subject. Drought indices are essential for monitoring drought since they simplify the complex climate functions and quantify climatic variance for their severity, duration, and frequency. The drought index calculator (DrinC) software is useful for monitoring the meteorological drought by calculating drought indices. Objectives. The main objective of this study is to use some drought indices such as SPI, RDI, and RD to monitor the severity of drought in a Mediterranean region of Türkiye, the province of Isparta, using DrinC Software. Method. The research work considered the period from 1960 to 2021 in order to calculate the indices such as standardized precipitation index (SPI), reconnaissance drought index (RDI), and rainfall deciles (RD). The software was used to facilitate the calculation of the indices considered in the study, which are specifically based on the gamma method over 3, 6, 9, and 12 months. Results. The results revealed that the years 1984, 1999, and 2015 recorded SPI-3 values of -1.51, -2.11, and -2.03, respectively. Additionally, the years 1989 and 1999 exhibited SPI values of -1.62 and -2.26, respectively. For SPI-9, the years 1999 and 2007 showed values of -1.66 and -1.51, respectively. Moreover, SPI values of -1.51, -1.68, and -1.94 were noted in the years 1988, 1989, and 1999, respectively. Results for the Rainfall Deciles method showed that, among 61 years, 12 years were affected by drought (lowest %20 much below normal), and the most affected years were 1972-1973, 1988-1989, 1989-1990, 1992-1993, 1999-2000, and 2007-2008. The R2 value of 0.95 showed that annual SPI and annual RDI were highly correlated, and the linear regression fit well. Conclusions. This study highlights the effectiveness of using indices such as SPI, RDI, and RD, for assessing meteorological drought in Isparta over 60 years. Results show varying drought severity and frequency across indices, with SPI identifying more extreme droughts. Strong correlations between SPI and RDI confirm their reliability, while the Pettitt test indicates a major breakpoint in 1970. The findings emphasize the need for multi-index approaches and integrating additional measures like soil moisture to improve drought monitoring and management strategies.
Determination of the Effects of Different Irrigation Levels and Vermicompost Doses on Water Consumption and Yield of Greenhouse-Grown Tomato
This study was conducted in pots under a polycarbonate greenhouse to determine the effects of different irrigation levels and vermicompost doses on the morphological and phenological characteristics, water consumption, water use efficiency, and yield parameters of tomato plants. For this purpose, different irrigation levels of 100%, 75%, 50% (I100: full irrigation, I75, I50) and vermicompost (VC) doses of 0, 10% and 20% (VC0, VC10 and VC20, w/w) were applied as the treatments. The study’s results determined the irrigation levels and vermicompost doses affected the tomato plants’ morphological and fruit quality parameters. The highest and lowest plant water consumption (ET) values for the treatments were determined as 47.8 L (I100VC10) and 21.2 L (I50VC0), respectively. Moreover, irrigation water levels and vermicompost doses significantly influenced the total yield of tomatoes. The highest and lowest total and marketable yields were obtained from the I100VC20 and I50VC0 irrigation levels and vermicompost doses. Similarly, the highest and lowest total water use efficiencies were achieved from the I100VC20 (21.9 g L−1) and I50VC0 (11.0 g L−1) treatments. Furthermore, the highest and lowest marketable water use efficiencies were obtained from the I100VC20 (21.9 g L−1) and I50VC0 (7.8 g L−1) treatments. The yield response factor (ky) was found to be 1.42. Although the highest efficiency was achieved from 100% full irrigation and a 20% vermicompost dose in the study, it is suggested that 75% irrigation level and 10% fertilizer doses can also be applied in places where water is limited and fertilizer is expensive. The results revealed that the appropriate irrigation level and vermicompost doses could reliably be used to enhance tomato yield.
The Importance of Rainwater Harvesting and Its Usage Possibilities: Antalya Example (Turkey)
The significance and effective use of water, one of the most basic requirements for sustaining vital activities, is gaining importance every day. Population growth and unprogrammed industrialization accelerate the consumption of available water resources. However, drought, as a result of climate change, poses a threat to water resources. Factors such as the exhaustibility of water resources, rapid population growth, unscheduled industrialization and drought increase the tendency towards alternative water resources. Rainwater harvesting is based on the principle of using the rainwater falling into the regions after it is stored. Water collected through rain harvesting can be utilized in many different areas, such as agricultural irrigation, landscape irrigation and domestic use. Among agricultural activities, the idea of water harvesting in greenhouse areas comes to the fore. Due to the gutters on the greenhouse roofs, water can be stored. In Antalya, which has about half of the greenhouses in Turkey, the amount of water in the rain harvest that can be obtained in greenhouses is 224,992,795.8 m3 per year. Monthly calculations throughout the year showed that the minimum water can be harvested in August (938,447.53 m3) and the maximum (54,771,210 m3) in December. Therefore, it is thought that some plant water consumption can be met by building sufficient storage in areas close to the greenhouse.
Evaluation of Crop Water Stress Index (CWSI) for High Tunnel Greenhouse Tomatoes under Different Irrigation Levels
An experiment was conducted to determine the effect of water stress on yield and various physiological parameters, including the crop water stress index for tomatoes in the Central Anatolian region of Turkey. For this purpose, the irrigation schedule used in this study includes 120%, 100%, 80%, and 60% (I120, I100, I80, I60) of evaporation from the gravimetrically. Water deficit was found to cause a stress effect in tomato plants, which was reflected in changes in plants’ morphological and pomological function (such as stem diameter, fruit weight, pH, titratable acidity, and total soluble solids). Irrigation levels had a significant effect on the total yield of tomatoes. The lowest water use efficiency (WUE) was obtained from the I60, while the highest WUE was found in the I100 irrigation level. The CWSI was calculated using an empirical approach from measurements of infrared canopy temperatures, ambient air temperatures, and vapor pressure deficit values for four irrigation levels. The crop water stress index (CWSI) values ranged from −0.63 to a maximum value of 0.53 in I120, from −0.27 to 0.63 in I100, from 0.06 to 0.80 in I80, and from 0.37 to 0.97 in I60. There was a significant relation between yield and CWSI. The yield was correlated with mean CWSI values, and the linear equation Total yield = −2398.9CWSI + 1240.4 can be used for yield prediction. The results revealed that the CWSI value was useful for evaluating crop water stress in tomatoes and predicting yield.
Genotype-Specific Responses to Drought During Seed Production in Carrot: Biochemical, Physiological, and Seed Quality Evaluation
Drought stress during the reproductive phase substantially reduces seed yield and quality, posing a major challenge to sustainable crop production under climate change. This study investigated the effects of drought stress at the flowering stage on selected biochemical and physiological parameters in 18 carrot accessions. To describe the long-term consequences of drought comprehensively, we examined seed quality parameters. Our analyses revealed that stress responses are highly dependent on the genotype and the parameter examined. Regarding antioxidant responses and potential tissue damage caused by drought, ‘Dolanka’, DC97, DC265, DC359, DC522, DC701, DC704, and DC720 exhibited the highest tolerance. The photosynthetic apparatus and pigments were maintained under stress in DC233, DC522, DC717, and DC728. Germination parameters served as reliable indicators of stress tolerance in DC97, DC359, DC432, DC522, DC701, and DC722 accessions. Based on these findings and detailed discussion of the results, we conclude that tolerance/sensitivity assessment of carrot genotypes should consider the holistic response of the plant rather than individual parameters. Through overall assessment, we recommended DC522 accession as the most drought-tolerant, given its enhanced ROS (Reactive Oxygen Species) scavenging mechanisms, increased chloroplast pigments accumulation, and superior germination parameters under drought conditions. Conversely, DC295 should not be cultivated under water-deficient conditions due to its impaired ability to detoxify ROS, altered photosynthetic activity, and disrupted seed germination under such conditions. These results collectively highlight the potential for selecting drought-tolerant carrot genotypes in breeding programs targeting improved seed performance under water-limited conditions, thereby supporting the development of resilient cultivars adapted to future climate challenges.
Effects of Silicon Application and Groundwater Level in a Subirrigation System on Yield of a Three-Cut Meadow
The increasing demand for food and animal products makes it important to ensure that animals have sufficient fodder obtained from grassland. Unfortunately, there has been a recent decline in grassland areas, which makes it essential to find solutions to increase the grassland’s productivity and the quality of the fodder it yields. One of these solutions may be the use of appropriate irrigation and fertilization. The present study investigated the effect of the foliar application of silicon fertilizer and the groundwater level in a subirrigation system on the yield of a three-cut meadow. Four different experimental plots were used: high groundwater level (HWL), high groundwater level with silicon application (HWL_Si), lower groundwater level (LWL), and lower groundwater level with silicon application (LWL_Si). The analyses showed that silicon significantly reduced the amount of dry matter obtained in each of the three meadow cuts during the year. Furthermore, the plot with a higher groundwater level had an annual yield of 12.69 Mg·ha−1, whereas when silicon was applied to this area, it was 10.43 Mg·ha−1 (17.8% reduction in dry matter). A similar trend was noted at lower water levels, in which silicon also caused a dry matter reduction. However, the experiment did not indicate a statistically significant effect of silicon application on plant height and NDVI values. These results show that further research is still needed to better understand silicon’s effect on meadow sward.
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.
The Effect of Irrigation and Vermicompost Applications on the Growth and Yield of Greenhouse Pepper Plants
In agricultural practice, improper irrigation levels and excessive fertiliser use negatively impact water resources and soil properties, respectively. This experiment aims to determine the effects of varying irrigation levels and vermicompost doses on the growth, quality, and productivity of pepper plants grown under polycarbonate greenhouse conditions. To achieve this objective, different irrigation levels (IL) of IL100 (100% full irrigation), IL75 (75%), IL50 (50%), and vermicompost doses (VD) of VD0 (0%), VD10 (10%), and VD20 (20%) were tested. The highest irrigation level was in the IL100–VD10 treatment, which also had the highest water consumption (ET) in the 27.8 L pot−1. By comparison, the IL50–VD0 treatment had the lowest irrigation level in the 15.4 L pot−1, representing nearly 55.4% of the maximum irrigation water amount. The findings showed that the irrigation levels and vermicompost doses had a significant impact on plant growth, quality, and fruit yield parameters. Accordingly, the irrigation levels and vermicompost doses had significant effects on the studied plant growth parameters (stem diameter, plant height, number of leaves, stem fresh weight, stem dry weight, root fresh weight, and root dry weight). Similar effects were also observed on the fruit quality parameters (fruit width, fruit length, fruit weight, fruit flesh thickness, pH, titratable acidity (TA), total soluble solids (TSS), chrome, and hue). This study found that the highest total yield (164.5 g pot−1), marketable yield (149.8 g pot−1), total water use efficiency (6.1 g L−1), and marketable water use efficiency (5.6 g L−1) were obtained at the 100% irrigation level. However, similar results were observed at the 75% irrigation level and a 20% vermicompost dose, where the total water use efficiency was 5.9 g L−1 and the marketable water use efficiency was 5.3 g L−1. This suggests that 75% irrigation can be a viable alternative to full irrigation (100%) and offers water-saving potential, particularly in areas with limited water resources.
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.
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.
Determination of the Effect of a Thermal Curtain Used in a Greenhouse on the Indoor Climate and Energy Savings
In order to reduce the impact of outdoor extreme weather events on crop production in winter, energy saving in greenhouses that are regularly heated is of great importance in reducing production costs and carbon footprints. For this purpose, the variations in indoor temperature, relative humidity and dew point temperature in the vertical direction (2 m, 4 m, 5.7 m) of thermal curtains in greenhouses were determined. In addition, depending on the fuel used, the curtains’ effects on heat energy consumption, heat transfer coefficient, carbon dioxide equivalents released to the atmosphere and fuel cost were investigated. To reach this goal, two greenhouses with the same structural features were designed with and without thermal curtains. As a result of the study, the indoor temperature and relative humidity values in the greenhouse with a thermal curtain increased by 1.3 °C and 10% compared to the greenhouse without a thermal curtain. Thermal curtains in the greenhouse significantly reduced fuel use (59.14–74.11 m3·night−1). Considering the heat energy consumption, the average heat energy consumption was 453.7 kWh·night−1 in the greenhouse with a curtain, while it was 568.6 kWh·night−1 in the greenhouse without a curtain. The average heat transfer coefficient (U) values were calculated at 2.87 W·m−2 °C with a thermal curtain and 3.63 W·m−2 °C without a thermal curtain greenhouse. In the greenhouse, closing the thermal curtain at night resulted in heat energy savings of about 21%, related to the decrease in U values. The use of a thermal curtain in the greenhouse reduced the amount of CO2 released to the atmosphere (116.6–146.1 kg·night−1) and fuel cost (USD 21.3–26.7·night−1). To conclude, extreme weather events in the outdoor environment adversely affect the plants grown in greenhouses where cultivation is performed out of season. A thermal curtain, used to reduce these adverse effects and the amount of energy consumed, is essential in improving indoor climate conditions, providing more economical greenhouse management and reducing the CO2 released into the atmosphere due to fuel use.
The effect of climate change on stream basin hydrometeorological variables: The example of Dim Stream (Turkey)
Effect of Subirrigation and Silicon Antitranspirant Application on Biomass Yield and Carbon Dioxide Balance of a Three-Cut Meadow
Meadows are valuable areas that play an important role in the carbon cycle. Depending on several factors, these areas can be carbon sinks or net emitters of carbon dioxide (CO2) into the atmosphere. In the present study, the use of an antitranspirant (AT) with silicon and the groundwater level in a subirrigation system in a three-cut meadow were evaluated on the carbon dioxide exchange balance and the yield of aboveground biomass. The study was carried out in four experimental plots: with high groundwater level (HWL), with a high water level with AT application (HWL_Si), with a lower groundwater level (LWL), and with a lower groundwater level and AT application (LWL_Si). Flux measurements were made using the closed dynamic chamber method. In the drier and colder 2021, the meadow was a net CO2 emitter (mean annual net ecosystem exchange (NEE) of all plots: +247.4 gCO2-C·m−2y−1), whereas in the more wet and warmer 2022, assimilation outweighed emissions (mean annual NEE of all plots: −187.4 gCO2-C·m−2y−1). A positive effect of the silicon antitranspirant application was observed on the reduction of carbon dioxide emissions and the increase of gross primary production (GPP) from the plots with higher groundwater levels. For the area with lower water levels, the positive impact of AT occurred only in the second year of the experiment. The yield of aboveground biomass was higher by 5.4% (in 2021) up to 11.7% (in 2022) at the plot with the higher groundwater level. However, the application of AT with silicon contributed to yield reduction in each cut, regardless of the groundwater level. On an annual basis, AT application with silicon reduced the yield by 11.1–17.8%.
