Search

Horticultural protected cultivation has spread throughout the world as it has proven to be extremely effective. In recent years, the greenhouse engineering research field has become one of the main research topics within greenhouse farming. The main objectives of the current study were to identify the major research topics and their trends during the last four decades by analyzing the co-occurrence network of keywords associated with greenhouse engineering publications. A total of 3804 pertinent documents published, in 1981–2021, were analyzed and discussed. China, the United States, Spain, Italy and the Netherlands have been the most active countries with more than 36% of the relevant literature. The keyword cluster analysis suggested the presence of five principal research topics: energy management and storage; monitoring and control of greenhouse climate parameters; automation of greenhouse operations through the internet of things (IoT) and wireless sensor network (WSN) applications; greenhouse covering materials and microclimate optimization in relation to plant growth; structural and functional design for improving greenhouse stability, ventilation and microclimate. Recent research trends are focused on real-time monitoring and automatic control systems based on the IoT and WSN technologies, multi-objective optimization approaches for greenhouse climate control, efficient artificial lighting and sustainable greenhouse crop cultivation using renewable energy.

Greenhouse microclimate control is important to reach high production yield and low environmental impacts. Ventilation, shading and evaporative cooling are methods for controlling air temperature and relative humidity inside the greenhouse. Ventilation and shading can be not sufficient to remove the excess heat, while evaporative cooling is based on the exploitation of huge amounts of water. In order to enhance the sustainability of the greenhouse industry, renewable energy sources can be exploited. Solar absorption systems can be used for greenhouse cooling in areas with high outdoor temperatures and solar radiation levels. These systems take advantage of the simultaneity between the solar energy availability and the greenhouse cooling demand allowing the reduction of conventional electricity and water consumption. They can be used in remote areas where conventional cooling is difficult and where there is abundant solar energy. This paper presents the results of the application of a solar cooling plant for climate control of a greenhouse. The system is sited at the University of Bari, Italy. The experimental plant consists of a Mediterranean greenhouse, having a surface of 300 m2 and by a single effect LiBr-H2O absorption chiller fed by evacuated-tube solar collectors. The application of two different localized distribution of cold inside the greenhouse was studied in order to evaluate the reduction of air temperature close to the cultivation area. A reduction of the greenhouse air temperature up 5.0°C was obtained.

The use of plastic materials in agriculture involves several benefits but it results in huge quantities of agricultural plastic waste to be disposed of. Input and output data on the use of plastics in agriculture are often difficult to obtain and poor waste management schemes have been developed. The present research aims to estimate and map agricultural plastic waste by using satellite images. Waste was evaluated by means of the indexes relating waste production to crop type and plastic application as defined by the land use map realized by classifying the Landsat 8 image. The image classification was carried out using Support Vector Machines (SVMs), and the accuracy assessment showed that the overall accuracy was 94.54% and the kappa coefficient equal to 0.934. Data on the plastic waste obtained by the satellite land use map were compared with the data obtained by using the institutional land use map; a difference of 1.74% was identified on the overall quantity of waste.

Increasing urban green infrastructure (UGI) in a city contributes to improve urban air quality and urban climate in summer, reducing buildings surface temperature, especially in southern Europe. UGI includes green walls and their correct application requires the knowledge of the energy performance of the applied green system. The effects of the green walls application on the building depend on the local climate, water availability, building shape. The presence of green walls affects the building microclimate all day, by reducing heat waves during the warm periods and heat losses from the building in cold periods. The heat and mass transfer between the external environment, the green wall and the building surface determine the building microclimate. Solar radiation, long wave infrared radiation, convective heat transfer and evapotranspiration are the main mechanism of heat transfer in a green wall. The paper describes the main parameters concerning heat flow in green walls that can be used in simulation models for predicting temperatures in buildings using the external weather conditions as model inputs. The green wall system was described by a schematic representation, the following layers were defined: the green wall, the gap air, the external surface of the building wall, the internal surface of the building wall, the air inside the building. The energy balance was defined for each layer and all the terms involved in the energy exchange between the layers were defined.

Green technology can represent a sustainable solution for construction of new buildings and for retrofitting of existing buildings, in order to reduce the energy demands of the buildings’ cooling systems, to mitigate the urban heat island and to improve the thermal energy performance of buildings. Green walls can allow the physical shading of the building, promote evapotranspiration in summer and increase thermal insulation in winter. An experimental test was carried out at the University of Bari (Italy) for 2 years. Three vertical walls, made with perforated bricks, were tested: two were covered with evergreen plants (Pandorea jasminoides and Rhyncospermum jasminoides), while the third wall was kept uncovered and used as a control. Several climatic parameters concerning the walls and the ambient conditions were collected during the experimental test. Daylight temperatures observed on the shielded walls during warm days were lower than the respective temperatures of the uncovered wall by up to 9.0°C. Night-time temperatures during cold days for the vegetated walls were higher than the respective temperatures of the control wall by up to 6.0°C. The absence in the literature of data concerning different seasons of the year is overcome in order to obtain a complete picture of building thermal performance in the Mediterranean climate region. © 2018 International Society for Horticultural Science. All Rights Reserved.

Green technology can represent a sustainable solution for construction of new buildings and for retrofitting of existing buildings, in order to reduce the energy demands of the cooling systems of buildings, to mitigate the urban heat island and to improve the thermal energy performance of buildings. Green walls can allow the physical shading of the building and promote evapotranspiration in summer and increase the thermal insulation in winter. Three vertical walls, made with perforated bricks, were tested at the University of Bari (Italy): two were covered with evergreen plants (Pandorea jasminoides variegated and Rhyncospermum jasminoides) while the third wall was kept uncovered and used as control. Several climatic parameters concerning the walls and the ambient conditions were collected during the experimental test. The daylight temperatures observed on the shielded walls during warm days were lower than the respective temperatures of the uncovered wall up to 8.4°C. The night-time temperatures during the cold days for the vegetated walls were higher than the respective temperatures of the control wall up to 3.6°C. © ISHS.

Plastic materials have been worldwide applied in agriculture for soil mulching, greenhouse covering, irrigation and drainage pipes, bags, containers, pots, and agrochemical containers. All of these plastic materials require, at the end of their lifetime, suitable collection and treatment systems. Agricultural activities in some areas of the Apulia Region, Southern Italy, are characterized by huge quantities of plastic wastes and local authorities and farmers associations have been interested in solving this problem by applying modern land management tools such as Geographical Information System (G.I.S.). In this paper a G.I.S. methodology is applied to an area of 10,200 ha in the Trani municipality, included in the Province of Barletta, Andria, Trani (BAT) - Apulia Region, in order to assess the agricultural plastic waste generation. The use of plastics at the agricultural farms has been investigated and related to the land use by applying statistical analysis, orthophoto analysis and remote sensing surveys. These data were introduced in a specific geo-database, and the agricultural plastic waste quantity and localization were defined. Vineyards and olive groves are scattered in this area, so the agricultural plastic waste mostly consists in irrigation pipes, after-use covering films and anti-hail nets used on vineyards. The analysis carried out showed that up to 614 kg ha-1 of covering films waste are yearly produced in some areas while the estimation of waste from the anti-hail nets was up to 159 kg ha-1 and the waste yearly produced from irrigation pipes was up to 83 kg ha-1. Through the use of the G.I.S., the areas with high density of plastic wastes were pointed out thus allowing to determine the suitable location of temporary storage areas and collecting points, in order to optimize the transport of agricultural plastic waste from the farms to the collecting points and to the recycling firms.

Building indoor air temperature depends on several different parameters related to the climate of the region, the building itself and its use. The main parameters influencing the microclimate are: external air temperature and relative humidity, incident solar radiation, long wave radiation exchange between the building surfaces and its surroundings, incidence and speed of the wind, air exchanges, physical and thermal properties of the building's envelope materials, design variables such as building dimensions and orientation, presence of artificial light, electrical equipment. A sustainable technology for improving the energy efficiency of buildings and to mitigate urban heat island is the use of green roofs and walls. The green technology can allow the physical shading of the building and promote evapotranspiration in summer and increase the thermal insulation in winter. An experimental test was carried out at the University of Bari (Italy). Three vertical walls, made with perforated bricks, were tested: two were covered with plants (one with Pandorea jasminoides variegated, the second with Rhyncospermum jasminoides) while the third wall was kept uncovered and used as control. A system composed by a data logger and sensors was used to measure and record the following parameters: temperature of the wall surface under solar radiation and of the surface on the other side of the wall, solar radiation falling on the wall, and external air temperature. The use of the green walls during cold months allowed increasing the thermal insulation performance of the walls by keeping the external surface temperature in nighttime hours up to about 2.8°C over the surface temperature of the wall not covered with plants. © 2017 ISHS.

Monitoring and controlling environmental parameters inside a greenhouse are required to reach high yields and low environmental impacts. Ventilation, shading, evaporative cooling and refrigeration are methods of controlling air temperature and relative humidity in Mediterranean greenhouses. Nevertheless ventilation and shading are often not sufficient to remove the excess heat, refrigeration is generally expensive and evaporative cooling is based on the exploitation of high quality water, a resource to be preserved in the Mediterranean areas. In order to enhance the sustainability levels of the greenhouse sector, renewable energy sources can be exploited with the application of solar absorption systems for greenhouse cooling in areas with high outdoor temperatures. These systems take advantage of the simultaneity between the solar energy availability and the greenhouse cooling demand allowing the reduction of conventional electricity. This paper presents the simulation and optimization of a solar cooling system designed for a Mediterranean greenhouse, having a surface of 300 m2, using 68 m2 of evacuated tube solar collectors, a LiBr absorption unit with a cooling capacity of 17.6 kW and a pilot distribution system providing the cooling power for the volume surrounding the crop. The simulation study, predicting the performance of the unit, was based on the experimental data collected at the experimental centre of the University of Bari, Southern Italy. The results of the simulation indicated that the system is seasonally in phase with the climatic data; the delivered yearly cooling capacity for the greenhouse was 113 GJ, the required solar energy 157 GJ and the available solar energy on the 68 m2 capturing surface, with a slope of 30°, was 265 GJ. The simulation can be used as a forecasting tool of the effects of the changes on the parameters of the system before applying them on the greenhouse system. © 2017 ISHS.