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Greenhouse microclimate depends on climatic parameters, such as solar radiation, air temperature, relative humidity and wind speed. The management of the greenhouse environment aims to ensure suitable growing condition for the crop, energy savings, and also safety condition for the workers. Solar absorption systems, exploiting renewable energy sources, can be applied for greenhouse cooling in regions with high values of solar irradiation in which evaporative systems are generally used; nevertheless evaporative systems require large quantity of water that is often a scarce natural resource in Mediterranean areas. The paper presents the technical considerations on the application of thermal solar collectors and an absorption system for cooling a greenhouse in the Mediterranean area. The simulation study was realized based on the data collected at the experimental centre of the University of Bari, Southern Italy, aiming to control the air temperature of a greenhouse having a surface of 300 m2. The study aims to delineate the solar collector surface related to the greenhouse cultivated area and the potential of the system in terms of cooling capacity and energy consumption. The designed system consists of 60 m2 of evacuated-tube solar collectors, a single-effect absorption chiller having a cooling capacity of 18 kW and a pilot distribution system, which provides the cooling power for the air volume surrounding the crop. The simulation showed that the delivered yearly cooling capacity for the greenhouse was 113 GJ, the required solar energy 157 GJ and the available solar energy 234 GJ.

Plastic materials are generally used for several agricultural applications and, at the end of their lifetime, they produce high volumes of waste to be disposed. A non suitable disposal system for agricultural plastic waste could induce economical damages, negative effects on the natural landscape and on the agroecosystem with loss of material or energy. Optimizing the processes of collection, transport and final disposal, the agricultural plastic wastes become "secondary raw materials", technically efficient and economically feasible, that can be reused for also other different applications. The problem of the management of the plastic waste flux coming from agricultural activities is still far to be solved in some Italian areas. In the present paper the management of agricultural plastic wastes was evaluated by means of the SWOT (Strengths Weaknesses Opportunities Threats) analysis and the application of a Geographical Information System (G.I.S). The methodology was applied to the municipality of Trani, in the Barletta, Andria, Trani Province (BAT), in Apulia Region, South Italy. The SWOT analysis was used to evaluate the whole process concerning the waste management, the GIS methodology was used to quantify plastic wastes generation on the land.

The phenomenon of urban warming, known as urban heat island, negatively influences outdoor comfort conditions and pollutants concentration, as well as increases the environmental impact due to the energy demand for air conditioning. In Mediterranean climate regions the main problem is to control the solar heat gain, that increases building’s temperature during the hot season, in order to protect the conditions of well-being of those who live or work in the buildings. Solar heat can be mainly reduced by increasing the insulation between the exterior and interior of the building, as well as shading the building surface from direct sun exposure. A sustainable technology for improving the energy efficiency of buildings is the use of green roofs and green walls in order both to reduce the energy consumption for conditioning in summer by physically shading the building structures and by promoting evapotranspiration, and to increase the thermal insulation in winter. Aim of this paper is to describe the green roofs and walls design requirements and to develop an energetic model capable of simulating the energy exchanges that take place in the presence of roofs / green walls. The energy model of the microclimate inside a building covered with plant species in Mediterranean climate depends on several different parameters that influence the indoor building microclimate such as external air temperature and relative humidity, incident solar radiation, long wave radiation exchange between the structure 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. The model takes into account also the effect of different plant species. Solar heat is transferred to the internal air through the envelope by the heat transfer mechanisms as conduction, convection and radiation. The physical properties of the surface, such as the solar reflectance, infrared emittance and the convection coefficient, influence the surface temperature. The use of green roofs and walls can contribute to mitigate the phenomenon of heat island, the emissions of greenhouse gases and the storm water runoff affecting human thermal comfort, air quality and energy consumption in buildings.

The use of plastic materials in agriculture causes the serious drawback of huge amount of wastes to be disposed of. In order to overcome this problem a new generation of biodegradable materials has been developed based on raw materials coming from renewable source. These materials retain their physical and mechanical properties during their lifetime and when they are integrated directly in the soil, the bacterial flora transforms them in carbon dioxide or methane, water and biomass. Biodegradable films can be made using natural polymers, such as starch, cellulose, chitosan, alginate and galactomannans. These materials can be obtained by means of thermoextrusion process, solvent casting and spraying technique. Mulch coatings can be realized directly in field by spraying water solutions based on natural polysaccharides, thus covering the cultivated soil with a protective thin geo-membrane. In this paper a focused overview on the formulation development, processing understanding, field performance and mechanical properties of these innovative materials for soil mulching is presented, in comparison to oil-based non renewable films. During their using time in field, the biodegradable mulches showed suitable mechanical properties if compared to the low density polyethylene films. At the end of their lifetime the biodegradable materials were shattered and buried into the soil together with plants. The film residues disposed of in the soil biodegraded in almost 1 month for the water borne coatings and in about 12 months for the biodegradable starch- based extruded films.

The management of the greenhouse environment depends on the manipulation of the climat-ic parameters, such as solar radiation, air temperature, relative humidity and carbon dioxide concentration, in order to guarantee suitable growing condition for the crop, safety condition for the workers and energy savings. Evaporative systems are generally used in warm regions for commercial greenhouse cooling, however such systems require large quantity of water that is often a scarce natural resource in Mediterranean areas. Solar absorption cooling sys-tems can be applied for greenhouse climate control in regions with high values of solar irra-diation as alternative to evaporative systems by exploiting renewable energy sources. The solar cooling system could provide significant energy-saving opportunities for cooling green-houses in hot climates allowing the reduction of electricity and water consumption by exploit-ing the contemporaneity between the cooling requirements and the solar energy availability. The paper presents the technical considerations on the application of a solar absorption cool-ing system to a Mediterranean greenhouse. The aim of the research was to define the poten-tial of the system in terms of energy absorption and the solar collector surface related to the greenhouse cultivated area. The simulation study was realized based on the experimental data collected at the experimental centre of the University of Bari, Southern Italy, in order to control the air temperature of a greenhouse covered with plastic film; the greenhouse was characterized by a surface of 300 m2. The cooling system was designed by adopting suitable technologies of energy saving, in order to reduce cooling energy needs. The designed sys-tem consists of an absorption chiller having a cooling capacity of 18 kW fed by 60 m2 of evacuated-tube solar collectors coupled to a new distribution system which provides the cooling power only for the air volume surrounding the crop and not for the whole greenhouse.