• Energy Research
• 2021-2025close

Bioenergy is being increasingly used worldwide to generate energy from biogas, biomethane, and other biofuels, bringing significant environmental and economic benefits. In Italy, biogas can significantly contribute to the achievement of the renewable energy targets set at the national and European levels. The exploitation of this energy source in a particular area is determined by its environmental and anthropic properties, as well as by the incentive system and the political will of decision makers. This paper analyzes the socioeconomic drivers and natural conditions triggering bioelectricity production in Italian regions. The analysis proposed here was performed in two steps—first, by identifying groups of similar regions for some natural, social, and economic variables, and then by modeling the historical trajectory of bioelectricity production for each identified group with innovation diffusion models. As a general finding, regions pertaining to the same group in terms of natural and socioeconomic conditions revealed a similar production pattern for bioelectricity, as confirmed by the results of diffusion modeling. On the basis of the diffusion modeling procedure, some scenario simulations were performed, which suggested the set-up of suitable policy actions for each group of regions.

The projected increase in temperature and water scarcity represents a challenge for winegrowers due to changing climatic conditions. Although heat and drought often occur concurrently in nature, there is still little known about the effects of water stress (WS) on grapevines in hot environments. This study aimed to assess whether the grapevine’s physiological and spectral responses to WS in hot environments differ from those expected under lower temperatures. Therefore, we propose an integrated approach to assess the physiological, thermal, and spectral response of two grapevine varieties (Vitis vinifera L.), Grenache and Shiraz, to WS in a hot environment. In a controlled environment room (CER), we imposed high-temperature conditions (TMIN 30 °C–TMAX 40 °C) and compared the performance of well-watered (WW) and WS-ed potted own-rooted Shiraz and Grenache grapevines (SH_WW, SH_WS, GR_WW, and GR_WS, respectively). We monitored the vines’ physiological, spectral, and thermal trends from the stress imposition to the recovery after re-watering. Then, we performed a correlation analysis between the physiological parameters and the spectral and thermal vegetation indices (VIs). Finally, we looked for the best-fitting models to predict the physiological parameters based on the spectral VIs. The results showed that GR_WS was more negatively impacted than SH_WS in terms of net photosynthesis (Pn, GR-WS = 1.14 μmol·CO2 m−2·s−1; SH-WS = 3.64 μmol·CO2 m−2·s−1), leaf transpiration rate (E, GR-WS = 1.02 mmol·H2O m−2·s−1; SH-WS = 1.75 mmol·H2O m−2·s−1), and stomatal conductance (gs, GR-WS = 0.04 mol·H2O m−2·s−1; SH-WS = 0.11 mol·H2O m−2·s−1). The intrinsic water-use efficiency (WUEi = Pn/gs) of GR_WS (26.04 μmol·CO2 mol−1 H2O) was lower than SH_WS (34.23 μmol·CO2 mol−1 H2O) and comparable to that of SH_WW (26.31 μmol·CO2 mol−1 H2O). SH_WS was not unaffected by water stress except for E. After stress, Pn, gs, and E of GR_WS did not recover, as they were significantly lower than the other treatments. The correlation analysis showed that the anthocyanin Gitelson (AntGitelson) and the green normalised difference vegetation index (GNDVI) had significant negative correlations with stem water potential (Ψstem), Pn, gs, and E and positive correlation with WUEi. In contrast, the photochemical reflectance index (PRI), the water index (WI), and the normalised difference infrared index (NDII) showed an opposite trend. Finally, the crop water stress (CWSI) had significant negative correlations with the Ψstem in both varieties. Our findings help unravel the behaviour of vines under WS in hot environments and suggest instrumental approaches to help the winegrowers managing abiotic stress.

Tomato drying is a time-consuming industrial process. Moreover, the prolonged use of high temperatures decreases the quality of tomatoes and increases the environmental footprint of the process. In most cases, drying is performed on halved tomatoes. Alternatively, the use of quarter tomatoes could guarantee a drying times reduction without compromising the final product quality. This work aimed at modelling changes in physical characteristics of half and quarter tomatoes. The drying tests were conducted at 50 and 60 °C. The kinetics of weight loss, colour change, and volume reduction were determined. Colour change was monitored through image analysis, while volume reduction using RGB-D reconstructions. Based on the results, an increase in the drying temperature and the use of quartered tomatoes allow a significant reduction in drying times. The loss of water kinetic allowed the determination of critical moisture. Between initial and critical moisture, loss of water occurred at constant rate (zero-order kinetic), while after that the rate decreased exponentially (first-order kinetic). The colour kinetics showed an initial constant rate followed by a linear increase for brown pixels. The variation of red pixels did not have a clear trend. Increasing the temperature there was no significant reduction in colour quality while quarter tomatoes showed a greater loss of redness than halved tomatoes. Furthermore, the temperature increase does not affect the volume reduction of the tomatoes. Increasing the temperature and the use of quartered tomatoes are simple solutions to reduce drying times. However, quartered tomatoes are less visually appreciable than halved tomatoes.

Agriculture is considered one of the most critical sectors that play a strategic role in ensuring food security. It is directly related to human development and social stability. The agricultural sector is currently incorporating new technologies from other areas. These phenomena are smart agriculture and smart irrigation. However, a challenge to research is the integration of technologies from different knowledge fields, which has caused theoretical and practical difficulties. Thus, our purpose in this study has been to understand the core of these two themes. We extracted publications in Scopus and used bibliometric methods for high-frequency word and phrase analysis. Research shows that current research on smart agriculture mainly focuses on the Internet of Things, climate change, machine learning, precision agriculture and wireless sensor networks. Simultaneously, the Internet of Things, irrigation systems, soil moisture, wireless sensor networks and climate change have received the most scholarly attention in smart irrigation. This study used cluster analysis to find that the IoT has the most apparent growth rate in smart agriculture and smart irrigation, with five-year growth rates of 1617% and 2285%, respectively. In addition, machine learning, deep learning and neural networks have enormous potential in smart irrigation compared with smart agriculture.

Rural buildings represent the functional relationship between rural communities and agricultural land. Therefore, research on rural buildings has practical repercussions on environmental and socio-economic sustainability. Comprehensive state-of-the-art research on rural buildings may address research activities. We present a systematic review of the scientific research between 2000 and 2022 based on the PRISMA protocol. Five main topics were identified. The results showed that the primary research focus was production (25.1%) and environmental management issues (23.2%). However, construction and efficiency are rapidly taking centre stage (20.6%). Regarding sustainability (20.8%), life cycle assessment, green buildings, recycling and global warming should be the future research focus. Energy efficiency will benefit from studies on thermal energy. More research on engineering and technologies (10.3%), specifically remote and automatic detection and transport in rural areas, will increase cost efficiency. The results may help improve the global efficiency of rural buildings in a modern farming system.

The exploitation of bioenergy plays a key role in the process of decarbonising the economic system. Huge efforts have been made to develop bioenergy and other renewable energy systems, but it is necessary to investigate the costs and problems associated with these technologies. Soil consumption and, in particular, soil sealing are some of these aspects that should be carefully evaluated. Agricultural biogas plants (ABPs) often remove areas dedicated to agricultural activities and require broad paved areas for the associated facilities. This study aimed to (i) assess the surfaces destined to become facilities and buildings in ABPs, (ii) correlate these surfaces with each other and to the installed powers of the plants, and (iii) estimate the consumption of soil in bioenergy applications in Italy. Two hundred ABPs were sampled from an overall population of 1939, and the extents of the facilities were measured by aerial and satellite observations. An ABP with an installed power of 1000 kW covers an average surface area of up to 23,576 m2. Most of this surface, 97.9%, is obtained from previously cultivated areas. The ABP analysis proved that 24.7 m2 of surface area produces 1 kW of power by bioenergy. The obtained model estimated a total consumption of soil by ABPs in Italy of 31,761,235 m2. This research can support stakeholders in cost-benefit analyses to design energy systems based on renewable energy sources.