Glass Greenhouse Research Articles

Modelling of micrometeorology, canopy transpiration and photosynthesis in a closed greenhouse using computational fluid dynamics

Closed greenhouse systems allow micrometeorological conditions to be optimised for both energy saving and high quality yields. However, micrometeorological parameters need to be accurately monitored as a response to daily environmental conditions changes. A Computational Fluid Dynamics (CFD) model was developed to predict the distribution of temperature, water vapour and CO2 occurring in a Venlo-type semi-closed glass greenhouse equipped with air conditioners. Sensible and latent heat fluxes in the crop rows were included in the model along with radiation through a Discrete Ordinates (DO) model. A model for photosynthesis was also included to predict the evolution of the CO2 concentrations inside the greenhouse. Comparisons between simulated and measured values showed a good agreement for temperature and humidity. Good agreement was found also between simulated and experimental CO2 concentration values determined during a sunny summer day. Simulations were also performed to investigate the vertical distribution of temperature and humidity for two different Leaf Area Density (LAD) values (2.95 m−1 and 5.9 m−1) and for different arrangements of the air conditioners. Simulation results showed that tall canopies, with high LAD, simultaneously induce a stronger cooling of the interior air. They also enhance temperature stratification providing a substantial decrease at canopy level. Lower suction also enhances stratification of the interior air.

Options for greenhouse development in Mexico

The export of fresh vegetables to the USA and Canada stimulates the development of protected horticulture in Mexico. While this opens opportunities for entrepreneurs, concerns with regards to sustainability in terms of water, energy and economy need attention. Water is scarce at some places, fossil energy is expensive, and profits and costs that are associated with greenhouse types and production levels determine the economic sustainability. The environmental and economic sustainability of greenhouses with different technological levels in the states of Aguascalientes, Queretaro and Sinaloa in Mexico was investigated. Aguascalientes and Queretaro are located in central Mexico at high altitudes, and Sinaloa is located along the north-western coast. Their climates differ substantially. Seven scenarios were assessed, ranging from a naturally ventilated greenhouse with a soil-grown crop to a greenhouse with much technology. The 'adaptive greenhouse approach' was used, combining the KASPRO greenhouse simulation model, the INTKAM simulation model for crop growth and development, and a financial model. Increasing technology results in increased production. With increased technology, water consumption increases (except at the highest level of technology), but energy consumption decreases (except in a greenhouse with a screen and a glass-covered greenhouse). Net income is highest for a glass-covered greenhouse for Aguascalientes and Queretaro, and for a plastic film greenhouse with heating, CO2, misting and screens for Sinaloa. If the most simple and most advanced greenhouses for Aguascalientes and Queretaro are excluded (as they are of very different technological levels), then pay-back periods for the remaining scenarios do not differ much. The pay-back period for Sinaloa is shortest for a plastic greenhouse with heating and CO2. Developmental opportunities exist in the (further) introduction of recirculation systems (water saving), heating (production, net income), screens and glass greenhouse cover (energy saving, production, net income), geothermal energy and solar panels (renewable energy).

Growth and Yield of Tomato and Cucumber Plants in Polycarbonate or Glass Greenhouses

We examined the effect of two greenhouse covering materials (glass or solid polycarbonate sheets) on the light environment and growth of tomato and cucumber plants. Spectral analysis showed that polycarbonate sheets entirely blocked radiation in both the UV - B (300 - 320 ㎚) and UV - A (320 - 400 ㎚) ranges, whereas glass transmitted UV - A and was only opaque to UV - B. The transmittance of photosynthetically active radiation (400 - 700 ㎚) and near infrared radiation (700 - 1100 ㎚) was higher in polycarbonate than glass. Air and soil temperatures were not significantly different between greenhouses covered with either material. The growth of cucumber plants was slightly affected by covering materials, whereas no significant changes in growth parameters were observed for tomato plants. The color parameters of tomato fruits were affected by the cover material, whereas cucumber fruits showed similar coloration in both glass and polycarbonate greenhouses.

Calibration and comparison of different CFD approaches for airflow analysis in a glass greenhouse

CFD has been increasingly applied to greenhouses to optimise indoor environmental conditions for cultivation and management. Numerical simulations have proved fundamental for the enhancement of energy-efficient design criteria and management procedures. The objective of the study is the comparison between different computational approaches for the study of airflow patterns in a representative study case of a glass greenhouse, also through the calibration of the models and the validation of simulation results against experimental data. A three-span greenhouse of about 300 m2 located in Emilia-Romagna (Italy) has been considered as study case. Several analyses with the same boundary and initial conditions were performed using two codes, broadly used for research and design purposes. With both programs, 2D or 3D models have been used and, for every case, the grid convergence was verified by performing multiple steady state analyses with increasingly finer meshes. The results led to define the most suitable solutions to set up computational models for the simulation of airflow patterns inside a greenhouse. The study provided a preliminary outline of the differences due to the adoption of various computational approaches characterised by different levels of accuracy and complexity. The results indicate the advisability of further developing the research by carrying out deeper experimental insights necessary to quantify more in detail the validity and the reliability of the adopted analytical methodologies.

Numerical and experimental study of a closed loop for ground heat exchanger coupled with heat pump system and a solar collector for heating a glass greenhouse in north of Tunisia

This work emphasizes the exploitation of renewable energy sources for heating a greenhouse, which requires the use of a horizontal heat exchanger, a heat pump associated with a solar collector in numerical and experimental investigations. This study demonstrates the performance of a heat pump system assisted by solar and geothermal energy under the climatic conditions of Tunisia. This system was designed and installed in Thermal Process Laboratory; Research and Technology Centre of Energy CRTEn Borj Cedria. The surface area and of the glass greenhouse used in the experimental model are 14.8 m2 as surface area. We precede several experimental data for realizing a numerical model based on TRNSYS software. For this point of view a numerical model was improved using 100 m2 and 229.5 m3 as surface and volume areas. The water-air heat pump is coupled with a ground heat exchanger (GHE) with 1m of depth. The distance between two consecutive tubes is 0.3 m. The surface area of the solar collector is 8 m2.

A Difference Study on the Lighting Simulation of the Illuminance Values from Daylight for the Glass Greenhouse

A Difference Study on the Lighting Simulation of the Illuminance Values from Daylight for the Glass Greenhouse

A METHOD OF RAPID CULTIVATION OF RADISH SEED PLANTS IN PLASTIC POTS OF SMALL-VOLUME

The development of cheap and rapid breeding methods to breed the lines used for hybrid F 1 production is a very actual task. The study was carried out with a use of radish varieties originated at VNIISSOK and breeding lines obtained by crossing components of different origin with male sterility in winter glass greenhouse. The mother plants were grown on the trays Plantec 64, while seedplants were grown in plastic pots of 1 liter capacity. The some morphobiological features such as the small habitus of see-plant; smaller number of secondary branching and absence of following branches; and consequently, the low yield of seeds were revealed in seed-plants of radish being grown in plastic pots. The period of ontogenesis in radish at first winter-spring rotation with this cultivation approach was reduced to 92 days. At the second summer-autumn rotation with additional lighting the duration of period of ontogenesis was essentially shorter than in the first rotation. The utilization of small-volume capacities in winter glass greenhouse to grow the radish seed-plants has permitted to produce two generations a year.

Broadband emission from Ce3+/Mn2+/Yb3+ tri-doped oxyfluoride glasses for glass greenhouse

In this work, a kind of oxyfluoride glasses tri-doped with Ce3+/Mn2+/Yb3+ ions was prepared by a simple and fast high temperature melting method. Under excitation with 300 nm light, two meaningful broad band emissions (ranged from 340 to 500 nm and 510–700 nm) were obtained, which matched well with the absorption of the chlorophylls. Under near-infrared (980 nm) excitation, an abnormal up-conversion luminescence was demonstrated in the oxyfluoride glasses by the energy transfer from Yb3+ to Mn2+. In addition, the up-conversion emission has a red shift along with the increase of the doping concentration of Mn2+, which would contribute to match the action spectrum of photosynthesis better. Our materials will be favored to extend the utilization of solar energy in glass greenhouse for plant cultivation.

Incremental Auto Regressive Prediction Models with External Variables of Greenhouse Air Temperature for Control Purposes

The impact of actuators should be considered in the prediction modeling of greenhouse air temperature. In this paper, the operating state of a greenhouse was divided into five sub-states based on the on-off characteristic of actuators. A group of novel incremental auto regressive models with external variables (IARX models) suitable for the five operat-ing sub-states were deduced from the mechanistic modeling of greenhouse air tempera-ture. The new IARX models have fewer coefficients than other known ARX models. In or-der to validate the IARX prediction models, the related environmental factors of a glass greenhouse were measured. The prediction results of the IARX models were compared with two typical ARX models. The maximum prediction errors and the mean square errors of the IARX models, under the three operating sub-states of passive state(all actuators are not working), mechanical ventilation and fan-pad cooling, are 0.1°C, 0.14°C, 0.7°C, and 0°C, 0.3°C, 0.4°C, respectively. The prediction results are much better than those of one compared model, while similar with the other.

Manipulating Sensory and Phytochemical Profiles of Greenhouse Tomatoes Using Environmentally Relevant Doses of Ultraviolet Radiation.

Fruits harvested from off-season, greenhouse-grown tomato plants have a poor reputation compared to their in-season, garden-grown counterparts. Presently, there is a gap in knowledge with regard to the role of UV-B radiation (280-315 nm) in determining greenhouse tomato quality. Knowing that UV-B is a powerful elicitor of secondary metabolism and not transmitted through greenhouse glass and some greenhouse plastics, we tested the hypothesis that supplemental UV-B radiation in the greenhouse will impart quality attributes typically associated with garden-grown tomatoes. Environmentally relevant doses of supplemental UV-B radiation did not strongly affect antioxidant compounds of fruits, although the flavonol quercetin-3-O-rutinoside (rutin) significantly increased in response to UV-B. Physicochemical metrics of fruit quality attributes and consumer sensory panels were used to determine if any such differences altered consumer perception of tomato quality. Supplemental UV-A radiation (315-400 nm) pre-harvest treatments enhanced sensory perception of aroma, acidity, and overall approval, suggesting a compelling opportunity to environmentally enhance the flavor of greenhouse-grown tomatoes. The expression of the genes COP1 and HY5 were indicative of adaptation to UV radiation, which explains the lack of marked effects reported in these studies. To our knowledge, these studies represent the first reported use of environmentally relevant doses of UV radiation throughout the reproductive portion of the tomato plant life cycle to positively enhance the sensory and chemical properties of fruits.

PLASTIC AND GLASS GREENHOUSES DETECTION AND DELINEATION FROM WORLDVIEW-2 SATELLITE IMAGERY

Greenhouse detection using remote sensing technologies is an important research area for yield estimation, sustainable development, urban and rural planning and management. An approach was developed in this study for the detection and delineation of greenhouse areas from high resolution satellite imagery. Initially, the candidate greenhouse patches were detected using supervised classification techniques. For this purpose, Maximum Likelihood (ML), Random Forest (RF), and Support Vector Machines (SVM) classification techniques were applied and compared. Then, sieve filter and morphological operations were performed for improving the classification results. Finally, the obtained candidate plastic and glass greenhouse areas were delineated using boundary tracing and Douglas Peucker line simplification algorithms. The proposed approach was implemented in the Kumluca district of Antalya, Turkey utilizing pan-sharpened WorldView-2 satellite imageries. Kumluca is the prominent district of Antalya with greenhouse cultivation and includes both plastic and glass greenhouses intensively. When the greenhouse classification results were analysed, it can be stated that the SVM classification provides most accurate results and RF classification follows this. The SVM classification overall accuracy was obtained as 90.28%. When the greenhouse boundary delineation results were considered, the plastic greenhouses were delineated with 92.11% accuracy, while glass greenhouses were delineated with 80.67% accuracy. The obtained results indicate that, generally plastic and glass greenhouses can be detected and delineated successfully from WorldView-2 satellite imagery.

PLASTIC AND GLASS GREENHOUSES DETECTION AND DELINEATION FROM WORLDVIEW-2 SATELLITE IMAGERY

Abstract. Greenhouse detection using remote sensing technologies is an important research area for yield estimation, sustainable development, urban and rural planning and management. An approach was developed in this study for the detection and delineation of greenhouse areas from high resolution satellite imagery. Initially, the candidate greenhouse patches were detected using supervised classification techniques. For this purpose, Maximum Likelihood (ML), Random Forest (RF), and Support Vector Machines (SVM) classification techniques were applied and compared. Then, sieve filter and morphological operations were performed for improving the classification results. Finally, the obtained candidate plastic and glass greenhouse areas were delineated using boundary tracing and Douglas Peucker line simplification algorithms. The proposed approach was implemented in the Kumluca district of Antalya, Turkey utilizing pan-sharpened WorldView-2 satellite imageries. Kumluca is the prominent district of Antalya with greenhouse cultivation and includes both plastic and glass greenhouses intensively. When the greenhouse classification results were analysed, it can be stated that the SVM classification provides most accurate results and RF classification follows this. The SVM classification overall accuracy was obtained as 90.28%. When the greenhouse boundary delineation results were considered, the plastic greenhouses were delineated with 92.11% accuracy, while glass greenhouses were delineated with 80.67% accuracy. The obtained results indicate that, generally plastic and glass greenhouses can be detected and delineated successfully from WorldView-2 satellite imagery.

Dynamic Mechanistic Modeling of Air Temperature and Humidity in the Greenhouses with on-off Actuators

The mechanistic models of greenhouse microclimate can be used as the simulators for designing new control strategies. According to the on-off characteristics of the actuators in greenhouse in China, the operating state of a greenhouse was divided into several sub-states, and new mechanistic models of greenhouse air temperature and humidity were built. In order to validate the new models, the relevant environmental factors under three sub-states were measured in a glass greenhouse. The mean square error of greenhouse air temperature and relative humidity are 0.57°C and 2.8% respectively. These results indicate that the new models are suitable for the development of energy-saving control strategies of greenhouse microclimate in future.

Design of Automatic Control Damper System for Heating and Cooling Energy Savings in Closed Glass Greenhouse

Design of Automatic Control Damper System for Heating and Cooling Energy Savings in Closed Glass Greenhouse

시설원예단지 조성이 농업생태계의 식생다양성에 미치는 영향 분석

인간은 생태계로부터 다양한 공익적 기능을 제공받고 있지만 시설원예단지 조성은 불투수면적 확장과 생물서식처 손실로 인해 기능저하의 원인이 될 수 있다. 시설원예단지 조성이 식물 종 다양성에 미치는 영향을 파악하였다. 식생분포 특성 분석결과 논에 비해 시설원예단지의 식물다양성이 상당히 낮다는 것을 알 수 있었다. 따라서 저 영향개발, 서식공간 배치, 식물 보전, 화학비료 사용제한, 서식처 조성, 보전비용 등을 제안하였다. 생활형 분석을 통해 일년생식물과 수생식물의 생육기반 환경 조성을 제시하였다. 귀화식물은 총 10과 20종류가 확인되었으며, 귀화율은 유리온실과 연동형 온실이 매우 높게 분석되어 콘크리트 피복을 지양하고 자연토양 피복을 유도 할 것을 제안하였다. 연구결과는 통계분석을 통해 확인하고 불투수면적을 자연형 토양으로 전환을 제안하였다. 본 연구결과는 지속가능한 농업경관 유지와 대규모 간척지 개발 사업에 있어 친환경, 생태적 시설원예단지 조성을 위한 정책자료에 활용되길 기대한다. Although the ecosystem extends numerous functions for the benefit of humankind, construction of horticultural facilities can potentially lead to the degeneration of some of these functions owing to the expansion of impervious regions and loss of habitats. Thus, this study aimed to examine the effect of construction of horticultural facilities on plant biodiversity. Analysis of the vegetation distribution characteristics showed that horticultural facilities had significantly lower plant diversity than did rice paddies. Hence, the proposed approach involved low-impact development, arrangement of habitat space, plant preservation, restricted use of chemical fertilizer, habitat creation, and reduced preservation cost. Lifestyle analysis suggested the importance of developing favorable environments for the growth of annual plants and aquatic plants. In all, 20 species of naturalized plants belonging to 10 families were identified. Furthermore, the proportion of these naturalized plants was higher in glass greenhouses and multi-span greenhouses, suggesting the advantages of employing natural soil mulching while avoiding concrete mulching. Statistical analysis was performed to validate the results, which suggested that impervious regions be converted to natural soils. Collectively, the findings of this study are expected to be used for establishing policies for the construction of eco-friendly and ecological horticultural facilities; this may aid the maintenance of sustainable agricultural landscapes and large-scale development of the reclaimed lands.

A new opinion of the greenhouse effect

The article analyzes the correspondence between the actually occurring physical and chemical processes and the concept of the greenhouse effect. The absorption of the solar radiation by the gases existing in the Earth's atmosphere has been examined. It was demonstrated that, despite the absorption of radiation from the Earth's surface in the middle and long-wave infrared (IR) regions, there is a strong absorption of the overtones and combined frequencies of water vapor in the solar radiation (visible and near IR regions), i.e., the transmittance bandwidth of ‘the glass greenhouse’. Thus, the Earth atmosphere does not really function as a greenhouse, and the terms ‘greenhouse effect’ and ‘greenhouse gases’ lost their original meaning and have remained symbolical.

The genes of reproductive system of Сapsicum genus and the search for ways of their application in conditions of covered soil in Ukraine

Pepper (Capsicum genus) is one of the most important vegetables and spices in the world. There is constant work in studying the genetics of pepper. New genes and genetic markers are discovered, previously discovered ones are studied in a fi ner detail. Aim. The aim of this work was to describe and systematize currently known genes of the reproductive system of Capsicum genus plants and to highlight the issue of using recessive mutant genes in the selection process while creating new varieties and hybrids of sweet pepper. Methods. The world collection of sweet pepper, current varieties and hybrids of different countries, our own selection material was used to classify reproductive genes in the selective studies. The experiments were conducted in conditions of plastic and glass greenhouses according to modern methods. Results. The data obtained were systematized into the following groups of genes: functional and genetic sterility, cytoplasmic male sterility, fertility restora- tion, female fertility and the ones, responsible for fl owering processes. A part of described genes may be used in heterosis plant breeding and while creating the original initial material. The examples of using recessive mutant genes while creating new varieties and hybrids of sweet pepper were presented along with their short characteristics. New varieties and hybrids of sweet pepper were introduced into the State register of varieties of plants, suitable for growing in Ukraine. Conclusions. The characterized genes may be used in genetic and selection studies. A number of new commercial varieties and hybrids of sweet pepper were created using reces- sive mutant genes.

Alternatives to Outdoor Daylight Illumination for Photodynamic Therapy--Use of Greenhouses and Artificial Light Sources.

Daylight-mediated photodynamic therapy (daylight PDT) is a simple and pain free treatment of actinic keratoses. Weather conditions may not always allow daylight PDT outdoors. We compared the spectrum of five different lamp candidates for indoor “daylight PDT” and investigated their ability to photobleach protoporphyrin IX (PpIX). Furthermore, we measured the amount of PpIX activating daylight available in a glass greenhouse, which can be an alternative when it is uncomfortable for patients to be outdoors. The lamps investigated were: halogen lamps (overhead and slide projector), white light-emitting diode (LED) lamp, red LED panel and lamps used for conventional PDT. Four of the five light sources were able to photobleach PpIX completely. For halogen light and the red LED lamp, 5000 lux could photobleach PpIX whereas 12,000 lux were needed for the white LED lamp. Furthermore, the greenhouse was suitable for daylight PDT since the effect of solar light is lowered only by 25%. In conclusion, we found four of the five light sources and the greenhouse usable for indoor daylight PDT. The greenhouse is beneficial when the weather outside is rainy or windy. Only insignificant ultraviolet B radiation (UVB) radiation passes through the greenhouse glass, so sun protection is not needed.

Performance and Feasibility Study of a Standing Column Well (SCW) System Using a Deep Geothermal Well

Deep geothermal heat pump systems have considerable energy saving potential for heating and cooling systems that use stable ground temperature and groundwater as their heat sources. However, deep geothermal systems have several limitations for real applications such as a very high installation cost and a lack of recognition as heating and cooling systems. In this study, we performed a feasibility assessment of a Standing Column Well (SCW) system using a deep geothermal well, based on a real-scale experiment in Korea. The results showed that the temperature of the heat source increased up to 42.04 °C in the borehole after the heating experiment, which is about 30 °C higher than that of normal shallow geothermal wells. Furthermore, the coefficient of performance (COP) of the heat pump during 3 months of operation was 5.8, but the system COP was only 3.6 due to the relatively high electric consumption of the pump. Moreover, the payback period of the system using a deep well for controlled horticulture in a glass greenhouse was calculated as 6 years compared with using a diesel boiler system.

A Remote Monitoring System for Greenhouse Based on the Internet of Things

The Internet of Things (IOT) is considered as a great opportunity for the development in the information field nowadays, and has been applied widely in many fields. The IOT can be applied to monitor and control the microclimate factors of greenhouse remotely. In this paper, a wireless monitoring network is designed in the perception layer of the IOT. The nodes are developed based on the Mica2 hardware and the TinyOS software. The LPL (low power listening) technology is adopted to reduce the energy consumption of the relay node which is powered by a solar panel. The ACK (Acknowledgement) mechanism is used in the software to improve the quality of wireless communications. A remote monitoring terminal is developed by using Java technology. The monitoring terminal is easy to operate with good interactivity. The system has been installed in a glass greenhouse. The actual operation results show that the system is stable and reliable, which lays a good foundation for the development of remote control strategies in future.