Mediterranean Climatic Conditions Research Articles

THE EFFECTS OF SOWING DESIGNS ON FORAGE YIELD AND QUALITY OF SWEET SORGHUM AND MUNG BEAN MIXTURES UNDER MEDITERRANEAN CONDITIONS

This study was conducted to determine the effects of sowing designs on forage yield and quality in sweet sorghum and mung bean grown as binary mixture with different cultivation systems in Mediterranean conditions under second crop season during 2019-2020. As sowing design, twin-row (20×55 cm row spacing), narrow-row (55 cm row spacing) and conventional-row (75 cm row spacing) were used as sowing design. The mixtures were formed based on the plant density and alternative row numbers of sweet sorghum and mung bean. Sowing was done on alternating rows of 1 row of sweet sorghum and 1 row of mung bean and 2 rows of sweet sorghum and 1 row of mung bean. The plant density of sweet sorghum was 14 plants m-2 and plant densities of mung bean were 14 plants m-2, 21 plants m-2 and 28 plants m-2. This experiment was planned as two-factor (sowing designs and mixtures) and conducted in randomized complete block design arranged in split plot with 3 replications. To evaluate the forage yield and quality, fresh forage yield, dry matter yield, NDF, ADF, ADL, crude ash crude protein and ether extract characteristics were examined. In addition, the intercropping potential of mung bean and sweet sorghum mixtures was evaluated by the land equivalent ratio. As a result of the present study, mixed cultivation of 14 plants m-2 with one row of sweet sorghum and 14 plants m-2 with one row of mung bean gave the best results in narrow row sowing design. It was concluded that an efficient and high quality intercropping system can be realized in the second crop conditions in regions where Mediterranean climatic conditions prevail, especially for mung beans and sweet sorghum.

Earliness, Yield, and Fruit Quality Attributes of Low-Chilling Peach-Nectarine Cultivars with the Application of Low Biuret Urea and Calcium Nitrate

This study aimed to determine the effects of low biuret urea and calcium nitrate application on earliness, fruit set, yield, and fruit quality characteristics in ‘Astoria’, ‘Maya’ peaches, and ‘Garbaja’ nectarine cultivars. In the study, Bud Feed (low biuret urea 15%) and calcium nitrate (calcium oxide 12% and total nitrogen 7%) were applied 35 days before bud break. In this study, flowering and fruit set, harvest times, fruit yield, and quality characteristics were evaluated. The source of temperatures used to calculate chill accumulation (expressed as hours below 7°C and chill unit) and growing degree hours was investigated. Bud Feed application provided earliness of 2 days in ‘Astoria’ and ‘Garbaja’ cultivars and 3 days in ‘Maya’ cultivar. This application was showed positive effect on flowering and final fruit set in all cultivars compared to control plants. The application was more effective in increasing the yield per tree by 33.72% (‘Astoria’), 41.00% (‘Maya’), and 52.18% (‘Garbaja’). Bud Feed application was improved fruit size in ‘Garbaja’ and ‘Astoria’ cultivars, whereas provided more intense fruit skin color in ‘Maya’ and ‘Garbaja’ cultivars. These results showed that bud feed and calcium nitrate application can be used to prevent yield and fruit quality losses in peach-nectarines in warm winter under Mediterranean climate conditions.

Biocrust-linked changes in soil aggregate stability along a climatic gradient in the Chilean Coastal Range

Abstract. Biological soil crusts (biocrusts) composed of cyanobacteria, bacteria, algae, fungi, lichens, and bryophytes stabilize the soil surface. This effect has mainly been studied in arid climates, where biocrusts constitute the main biological agent to stabilize and connect soil aggregates. Besides, biocrusts are an integral part of the soil surface under Mediterranean and humid climate conditions, mainly covering open spaces in forests and on denuded lands. They often develop after vegetation disturbances, when their ability to compete with vascular plants increases, acting as pioneer communities and affecting the stability of soil aggregates. To better understand how biocrusts mediate changes in soil aggregate stability under different climate conditions, we analyzed soil aggregate samples collected under biocrust communities from four national parks in Chile along a large climatic gradient ranging from (north to south) arid (Pan de Azúcar, PA), semi-arid (Santa Gracia, SG), Mediterranean (La Campana, LC) to humid (Nahuelbuta, NA). Biocrust communities showed a stabilizing effect on the soil aggregates in dry fractions for the three northern sites and the wet aggregates for the southernmost site. Here, permanent vascular plants and higher contents of organic carbon and nitrogen in the soil control aggregate stability more than biocrusts, which are in intense competition with higher plant communities. Moreover, we found an increase in stability for aggregate size classes < 2.0 and 9.5–30.0 mm. The geometric mean diameter of the soil aggregates showed a clear effect due to the climatic gradient, indicating that the aggregate stability presents a log-normal instead of a normal distribution, with a trend of low change between aggregate size fractions. Based on our results, we assume that biocrusts affect the soil structure in all climates. Their role in aggregate stability is masked under humid conditions by higher vegetation and organic matter contents in the topsoil.

Establishment of a commercial organic hopyard in a Mediterranean environment: Production attributes and their relationship with soil texture

The cultivated hops are recently moving towards new growing areas in Southern Europe, boosted by the increasing number of craft breweries and by the higher vulnerability to climate change observed, for this crop, in the traditional growing regions. Despite this clear market and geographic trend, there is a lack of knowledge about pedoclimatic needs and agronomic performances of hops grown in the Mediterranean environment. Particularly, the agronomic potential of a new hopyard during its establishment period is poorly studied even in traditional growing zones. Moreover, a restricted number of plants were usually sampled to gather the few data available, thus leading to a probable overestimation of yield performance. A commercial organic hopyard in central Italy was established and a 2-year (2018–2019) field experiment was set-up to accurately investigate the cone and shoot yield potential of cultivar ‘Cascade’ and to understand how such yields are related to each other and to soil texture. Hop plants were two-years old when the experiment started; plant population was 4,000 plants ha−1. Forty points within the hopyard were sampled for soil analysis and yield traits. Data were analyzed accounting for spatial dependence of the sampling points. Results show a negative relation between clay content in the soil and hop yields, even though it was significant only in the exceptional rainy season of 2018. Shoot and cone yield were positively and strongly related, suggesting the green shoot yield in spring as a good predictor of hop production. Both shoot and cone yield significantly increased from the second to the third year (+11% and +16%, respectively); however, the unseasonably high rainfall of 2018 probably lowered the yield of the first experimental year. Cone yield attained over this 2-year study (1.24 t ha−1 and 1.44 t ha−1 for 2018 and 2019, respectively) was within the published ranges for mature plants. Similarly to cone production, shoot dry matter yield was lower in 2018 (197 kg ha−1) than in 2019 (218 kg ha−1). This study provides the first reliable information on both cone and shoot yield potential of a young organic hopyard under Mediterranean climatic conditions.

Energy performance evaluation for a floating photovoltaic system located on the reservoir of a hydro power plant under the mediterranean climate conditions during a sunny day and a cloudy-one

• The world’s biggest Floating Photovoltaic unit of its kind is considered. • Floating membrane is used as the floating technology. • Values of final yield, performance ratio, and system efficiency are estimated. • Performance data during a clear day and a cloudy one are compared. Deployment of photovoltaic systems on water bodies unlocks enormous areas in populated regions. Also, their utilization will create the possibility to increase the share of photovoltaics systems related to the energy transition. There is little information regarding the available data for floating photovoltaic systems (FPVS). The positive effect of water on cooling the photovoltaic modules should be considered, also. This study is performed by utilizing experimental data from a field test located in a region having Mediterranean Climate Conditions. It is a newly installed FPVS with an installed capacity of 0.5 MW p DC. The unit is the world’s biggest of its configuration referred to the installed capacity and its diameter. Results include the energy yield, final yield, performance ratio, capacity factor, and system efficiency. They refer to a daily period during sunny and cloudy days and offer a clear view regarding the system operation. For the considered sunny and cloudy days, it is noticed that the daily final yields are 7.289 kWh/(kW p ·day) and 3.572 kWh/(kW p ·day), respectively. The daily performance ratio is 86.9% (sunny day) and 89.8% (cloudy day). Also, the daily system efficiency in the selected days are 17.4% and 17.9%, respectively.

Management of Nitrogen Fertilizer in Monoculture Wheat System under Mediterranean Climate Conditions

The production of durum wheat in Algeria is hardly sufficient for the growing demand for this product. Dependent on climatic hazards, the national average yields which hardly exceed 10 q ha-1, are mainly due to a lack of mastery of production techniques such as fertilization, plant protection, supplemental irrigation, etc. The aim of the undertaken experimentation was to constitute a nitrogen fertilization strategy for durum wheat that fit the region of the plains of Constantine in Algeria. Based on the form of fertilizer, the method, and the time of application, the experimentation profited from good soil and good climatic conditions. For that, we established an experimental device including various methods of contribution: ground and foliar nitrogen fertilizers, split or fully applied at-planting. The analysis of growth parameters and yield components showed that any nitrogen input results in improvements whatever its form or modality. Moreover, the method with a single application of nitrogen fertilizer at-planting on the ground was most efficient for the whole of the studied parameters, except the length of the ear where we observed the best result with foliar supply.

Bazı Azot ve Fosfor Düzeylerinin Tatlı Sorgum (Sorghum saccharatum) Bitkisinin Tane Verimi ve Bazı Verim Bileşenlerine Etkileri

Sweet sorghum is a multi-purpose crop due to the use of all plant parts. The research was carried out under controlled conditions to evaluate the effect of fertilization management on growth, grain yield and yield characteristics of sweet sorghum grown as a second crop in Mediterranean climate conditions. The experiment was carried out two-factor randomized plot trial with 20 treatments combination of 5 nitrogen levels (0, 50, 100, 150, 200 kg N/ha) and 4 phosphorus levels (0, 50, 100, 150 kg P/ ha) with 3 replications. Some properties were investigated in the study such as, plant height, harvest index, thousand grain weight and grain yield per plant and some characteristics related to yield. The results shown that plant height of sweet sorghum increased with increasing N and P levels up to 200 kg N or 150 kg P per hectare, respectively, but increase beyond 100 kg N or P/ha was not found significant in general. Other features related to yield followed almost the same trend. Grain yield per plant of sweet sorghum increased linearly with increasing levels of N and P up to 200 kg N and 150 kg P/ha in both years. The combined application of 150 kg N + 150 kg P/ha produced highest grain yield.

Species specific vulnerability to increased drought in temperate and Mediterranean floodplain forests

Floodplain forests are sensitive to climate warming and increased drought, as showed by recent oak (Quercus robur) dieback and mortality episodes. However, a comprehensive comparison of coexisting tree species under different climate settings or biomes are lacking. Herein, we compared growth rates, growth responses to climate and drought severity, and modeled climate mediated growth of oak and three coexisting tree species (ash, Fraxinus angustifolia; alder, Alnus glutinosa; elm, Ulmus minor). Two floodplain forests subjected to cooler (temperate climate, Ticino) and warmer (Mediterranean climate, Bosco Pantano) conditions in northern and southern Italy, respectively, were analyzed. Ash seemed to be the most sensitive to drought, particularly at the Mediterranean site where oak and elm growth were also negatively affected by water shortages. Alder appeared to be the least sensitive species in terms of growth variability to drought under both temperate and Mediterranean climate conditions. Furthermore, the growth model revealed the influence of soil moisture in spring and summer on the constrained growth of ash and oak and illustrated how oak growth could be severely reduced during drastic hotter droughts. Alder seemed to be the most drought-resistant species under both environmental conditions. These results could represent the first attempts in documenting the ecological consequences of drought in terms of projected climate trends in less investigated Mediterranean floodplain forests. Furthermore, these results highlight how climate and tree-ring data combined with growth models could be useful tools to detect early warning signals of growth decline and impending dieback in floodplain forests in response to dry spells.

The potential of multilayer green roofs for stormwater management in urban area under semi-arid Mediterranean climate conditions

Different low impact development measures have been proposed to make cities more flood-resilient, and recent literature is paying great attention to the evaluation of their direct benefits in terms of flood risk mitigation and the numerous co-benefits that they may offer. This study describes an experimental prototype of a technologically advanced multilayer green roof installed in a Mediterranean urban area (i.e., Palermo, Italy) and explores the results of an analysis of data collected over a one-year monitoring period by a complex sensors network.Multilayer green roofs, or “blue-green” roofs (BGRs), are characterized by a high water retention capacity compared to traditional green roofs due to the presence of an additional storage layer (blue layer), usually equipped with a valve that allows for regulating discharge outflow and water storage. Due to their recent development, BGRs are still scarcely explored in literature and have never been tested before in semi-arid environments, where they could represent valid measures to counter possible climate change and growing urbanization effects.In this study, the hydrological effectiveness of the experimental BGR is quantitatively evaluated by using appropriate indicators, based on the comparison between the hydrological response of the system and an equal size benchmark “grey” roof. The analyses are prevalently focused on the system's stormwater retention function, also investigating the relative contributions of the green layer and the storage layer to the overall retention capacity through the introduction of new BGRs specific indicators.Results emphasize the high impact of storms characteristics, antecedent soil moisture of the green layer, and initial water storage in the blue layer on the system's retention capacity. The overall mean retention rate for the experimental BGR, on average equal to 77% at the daily scale and 61% at the event scale, is comparable to the typical values of traditional extensive green roofs and could be further improved through a “retention-oriented” management of the outflow valve. The system was able to entirely retain almost half of the rainfall events occurred during the monitoring period and, for all the others, it was however extremely effective in reducing runoff peaks and delaying the hydrograph produced.

Remote Sensing Monitoring of Durum Wheat under No Tillage Practices by Means of Spectral Indices Interpretation: A Preliminary Study

Due to its advantages, remote sensing monitoring has been used in various applications and made noteworthy contributions to understanding soil and plant processes, as well as in the agriculture sector. The aim of the work is to compare the return of durum wheat crops in conservative agricultural practices in Mediterranean climate conditions by analysing the data from the Sentinel2 satellite through three spectral indices. The analysed spectral indices have different interpretations and therefore have been studied in different periods: (i) NDVI (normalized difference vegetation index) for the evaluation of the vegetative vigour from January to June; (ii) NDWI (normalized difference water index) for the moisture of covered soil from January to June and of bare soil after harvesting from June to August; and (iii) NMDI (normalized multi-band drought index) for the variability of bare soil moisture from June to August. With reference to the machines used in cultivation practices, a further purpose of the study is to investigate the effects of automatic guidance versus manual guidance on production yields and on the spectral indices considered. The first results show that the NDVI follows crop phenological stages by reaching the maximum values in correspondence with the stem elongation and booting stages. Additionally, the NDWI showed the same trend as the NDVI during the current crop. After harvesting, the NDWI showed higher values in the plots cultivated under conservation tillage practices. In the same period, the NMDI showed the same results as the NDWI and a positive correlation, confirming that tillage practices could imply a lower ability to retain water in drought time.

Phenotypic Diversity of Seminal Root Traits in Bread Wheat Germplasm from Different Origins.

Bread wheat (Triticum aestivum L.) is a major staple crop, and more adapted varieties are needed to ensure productivity under unpredictable stress scenarios resulting from climate changes. In the development of new genotypes, root system traits are essential since roots have a key function in water and nutrient uptake, and root architecture determines the plant's ability to spatially explore the soil resources. Genetic variation in wheat root system may be assessed at the early stages of development. This study evaluates in vitro and at the seedling stage, the genetic diversity of root growth angle (RGA), seminal root number (SRN), and radicle length (RadL) in 30 bread wheat genotypes from different origins and belonging to distinct evolutive or breeding groups. SRN and RadL were analyzed at 1, 2, 3 and 6 days after sowing (DAS) and RGA was measured through the angle between the first pair of seminal roots. A large variability was found in RGA values that ranged from 63° to 122°. Although differences were found between genotypes within the same groups, the narrower angles tended to occur among landraces, while the higher RGA values were observed in advanced lines and Australian varieties. Differences were also observed as regards the SRN (1.0-3.0, 2.7-4.7, 3.2-5.0 and 4.4-6.3 at 1, 2, 3 and 6 DAS, respectively) and RadL (0.1-1.5, 2.1-5.0, 4.0-7.5 and 5.1-13.7 cm at 1, 2, 3 and 6 DAS, respectively). Genetic variability in root traits at seedling stage allows more rapid selection of genotypes better adapted to environmental and soil constraints, necessary to Portuguese Wheat Breeding Program. It will also contribute to the definition of wheat ideotypes with improved performance under Mediterranean climate conditions.

A GIS‐based multicriteria decision analysis to reduce riparian vegetation hydrogeological risk and to quantify harvested biomass (Giant reed) for energetic retrieval

The vegetation development in riverbeds creates obstructions to the regular water flow with the flooding hydraulic risk increase. Giant reed (GR) (Arundo donax L.) is one of the most successful invasive species of riparian ecosystems in Mediterranean semi-arid climate conditions, with significant public administrations costs for its removal and disposal. At the meantime, due to its high biomass yield and adaption capacity to several conditions, GR is a very promising no-food crop to produce biogas by the anaerobic digestion (AD). The research activity provides for the involvement of territories belonging to the inner areas of Sicily, especially Calatino one, in which the SIMBIOSI Consortium operates an AD plant fed with agricultural by-products from other close agro-industrial companies. The aim of the study was to map and to quantify the actual spatial distribution of GR in watercourses embankments through Remote Sensing (RS) techniques applied in a Geographic Information System (GIS) environment. In this regard, a method based on the automatic supervised classification, was applied on three different combinations of spectral bands (True Color Image – TCI; Near-Infrared, Green and Blue – NGB; Vegetation Red Edge – VRE) of Sentinel-2 satellite images related to the summer season (11th August 2019), with the aim of identifying the most suitable classification to map the GR. The results showed that the VRE composition is the most accurate combination of spectral bands for the identification of GR, followed by the NGB image. The worst performance was obtained by using the TCI combination. A further elaboration was carried out combining the three classified images, in order to obtain a more accurate localization and quantification of GR. The final thematic map allowed to correctly classify GR for the 46 % of the cases, with an overall accuracy of 85.02 % and a high Kappa Coefficient of Agreement value equal to 0.81. Finally, the surface covered by GR in the study area (computed in the GIS environment) was about 2 km2 and the estimated GR biomass, available for the biomethane production, obtainable from watercourses embankments maintenance interventions would amount to about 11,780 tons year−1. The study could contribute to the development of a watercourses maintenance plan with the aim to reduce the risk of streams flooding in valley areas and at intersections with infrastructure works. Furthermore, the proposed methodology can be used by stakeholders in marginal areas, for the watercourses management, offsetting its costs through the energy use of the collected biomass.

Impact of Different Fertilizer Forms on Yield Components and Macro–Micronutrient Contents of Cowpea (Vigna unguiculata L.)

Organic materials, whose importance is increasing day by day in terms of soil fertility, plant nutrition, and sustainable agriculture in the world, need to be shown to be more effective against chemical fertilizers in order for farmers to adopt and use them more. The study was carried out to determine the effects of different organic fertilizer forms (farmyard manure (FM1 = 2500, FM2 = 5,104,000, FM3 = 7500, and FM4 = 10,000 kg ha−1), leonardite (L1 = 5000 and L2 = 10,000 kg ha−1) and vermicompost (V1 = 2500, V2 = 5000, V3 = 7500, and V4 = 10,000 kg ha−1)) on the yield components and some macro and micronutrient contents of the cowpea (Vigna unguiculata L.). The study, which was carried out under the Kahramanmaraş Mediterranean ecological conditions in 2020–2021, was conducted according to the experimental design of completely randomized blocks with three replications. As a result of the study, it was found that the differences between the fertilizer forms were significantly effective in terms of all the examined characteristics. It was determined that the seed yields varied between 3043.3–4126.7 kg ha−1, and according to the results of the two-year study, 10,000 kg ha−1 vermicompost would be sufficient to obtain the highest cowpea yield (4126.7 kg ha−1) under Mediterranean climate conditions.

Optimization, design and control of a photovoltaic/wind turbine/battery system in Mediterranean climate conditions

The goal of this study is to design and optimize a photovoltaic/wind turbine/batteries system. The application is made in the area of Bejaia (Algeria), a Mediterranean region where the solar and wind energy are extremely exploitable in this area due to its geographical location. The total incident energy approach was used to develop the device under consideration. To optimize power, the fuzzy logic control (FLC) is applied and to highlight the benefits of this maximum power point tracking (MPPT) strategy, it was compared to perturb and observe (P and O) method. A power management control has been applied. The findings from the three different days are displayed and analyzed to demonstrate the applicability of the suggested system. The examined system is assessed using the Homer software to demonstrate the best feasible integration of the several sources at the Bejaia location. There has been an increase in renewable power, which is one of the study's key novelty and objectives, so less stress on batteries in a PV/wind system. This is owing to the suggested accurate sizing procedure and to the FLC algorithm. The findings of the suggested study under various solar irradiation and wind speed velocity profiles are presented to demonstrate its applicability.

Assessing the energy and water balance dynamics of rain-fed rooibos tea crops (Aspalathus linearis) under changing Mediterranean climatic conditions

Rooibos (Aspalathus linearis), a herbal tea crop and a member of the plant family Fabaceae, grows in a narrow ecological range under Mediterranean conditions in South Africa's fynbos biome. There is growing uncertainty on the sustainability of rooibos production under rain-fed conditions in a region which is expected to get warmer and drier in future. No accurate quantitative information currently exists on how the water use, growth and yield of this crop is affected by environmental factors, especially climate and soils. This paucity of data reduces the ability of farmers to develop effective strategies to cope and adapt to the negative effects of climate variability and change. The aim of this study was to investigate the seasonal changes in the energy and water balance of rooibos fields and to establish how this relates to crop yield. An open path eddy covariance system was used to quantify the actual evapotranspiration (ETa) and energy balance components over two growing seasons while sap flow was monitored using stem heat balance sap flow gauges. These data were used to develop and test a simple ETa and yield model which was applied to estimate changes in crop water use and yield under the predicted future climatic conditions. More than 36% of the annual total ETa (∼ 338 mm) was consumed during the first three months of the growing season (September to November) driven by residual soil moisture from the winter rains. Crop transpiration accounted for only 16% of ETa early in the growing season rising to almost 100% during the summer dry months. Daily peak transpiration at maximum canopy cover barely reached 1.0 mm suggesting that this crop uses very little water. Six climate change models were used to simulate crop water use and yield for the far future under the RCP 8.5 emission scenario. All the models predicted increases in both the annual ETa and yield by between 8% and 16% in the period 1961–2099. This study reveals that implementing water conservation and weed management practices early in the growing season can save substantial amounts of soil moisture which can sustain rooibos production under low rainfall conditions.

Experimental assessment of ground-truth faults in a typical single-duct dual-fan air-handling unit under Mediterranean climatic conditions: Impact scenarios of sensors’ offset and fans’ failure

Data-driven Automated Fault Detection and Diagnosis (AFDD) is the automated process of detecting deviations (faults) from normal operation and diagnosing the type of problem and/or its location based on the exploitation of data collected under normal and faulty conditions. The performance of a typical single-duct dual-fan constant air volume air-handling unit (AHU) are investigated through a number of experiments performed during Italian cooling and heating seasons under both fault free and faulty scenarios. The AHU operation is analysed while artificially introducing six typical faults: 1) positive offset (+3 °C) of the return air temperature sensor; 2) negative offset (−3 °C) of the return air temperature sensor; 3) positive offset (+15 %) of the return air relative humidity sensor; 4) negative offset (−15 %) of the return air relative humidity sensor; 5) complete failure of the return air fan; 6) complete failure of the supply air fan. The faulty tests are compared with the fault free experiments performed under the same boundary conditions to assess the impacts of the faults on both thermal/hygrometric indoor comfort and patterns of key operating parameters with the aim of supporting the studies focusing on new and accurate data-driven AFDD methods for AHUs.

Faulty Operation of Coils’ and Humidifier Valves in a Typical Air-Handling Unit: Experimental Impact Assessment of Indoor Comfort and Patterns of Operating Parameters under Mediterranean Climatic Conditions

Data-driven Automated Fault Detection and Diagnosis (AFDD) are recognized as one of the most promising options to improve the efficiency of Air-Handling Units (AHUs). In this study, the field operation of a typical single-duct dual-fan constant air volume AHU is investigated through a series of experiments carried out under Mediterranean (southern Italy) climatic conditions considering both fault-free and faulty scenarios. The AHU performances are analyzed while artificially introducing the following five different typical faults: (1) post-heating coil valve stuck at 100% (always open); (2) post-heating coil valve stuck at 0% (always closed); (3) cooling coil valve stuck at 100% (always open); (4) cooling coil valve stuck at 0% (always closed); (5) humidifier valve stuck at 0% (always closed). The measured faulty data are compared against the corresponding fault-free performance measured under the same boundary conditions with the aim of assessing the faults’ impact on both thermal/hygrometric indoor conditions, as well as patterns of 16 different key operating parameters. The results of this study can help building operators and facility engineers in identifying faults’ symptoms in typical AHUs and facilitate the related development of new AFDD tools.

A New Fertilization Approach for Bread Wheat in the Mediterranean Environment: Effects on Yield and Grain Protein Content

Plant biostimulants represent an innovative and sustainable solution to address the challenges of the future agriculture, especially when they are used to improve yield and quality of staple crops. The objective of this research was to study, over three consecutive seasons, the effect of a novel fertilization plan (Thesis 2, T2) on the productivity and protein content of bread wheat (Triticum aestivum L.), as compared to the traditional fertilization pattern (Thesis 1, T1), commonly used in Tunisia. T2 was based on the use of a pre-sowing soil bioenhancer (SBE, commercially known as ‘Terios’) and a topdressing with foliar bio-stimulant (FBS, commercially known as ‘Celerios’), obtained by nanotechnology transformation of Y-CaCO3 minerals (called ‘vaterite’); while T1 was based on the use of diammonium phosphate (DAP) at pre-sowing and ammonium nitrate (AN) during the growing season. FBS was applied two times each season and at one rate (3 kg ha−1). In each farm and experimental year, the following traits were recorded: plant height (cm), whole aerial biomass (t DM ha−1), grain yield (t ha−1, 13% moisture content), harvest index, grain weight (mg), spike density (number of spikes per m2), grain protein content (%). T2 protocol slightly, but significantly, increased yield, yield components and grain protein content, while it decreased plant height at harvest. These results suggest that the use of FBS could be of great interest for the cultivation of bread wheat under Mediterranean climatic conditions, as it can make plant nutrients rapidly available even when the uptake from the soil is hindered by water scarcity.

Why Intra-Annual Density Fluctuations Should Be Formed at Night? Implications for Climate–Growth Relationships in Seasonally Dry Conifer Forests

Trees grow at night, when the vapor pressure deficit (VPD) is low enough. Therefore, intra-annual density fluctuations (IADFs) should be formed when the VPD drops below a certain threshold. This idea is tested by assessing climate-latewood IADF relationships in six conifer species under Mediterranean climate conditions. Hourly climate and dendrometer data were analyzed for years with elevated IADF production in two species (Pinus halepensis, Juniperus thurifera). Lastly, climate–growth relationships were evaluated in two drought-prone sites to assess the relative role of minimum vs. maximum temperatures as growth drivers. Latewood IADF production was positively related to growth rate. IADFs were more abundant when monthly or 10-day long precipitation was high in the late growing season (August and September). According to dendrometer data, growth mainly occurred in early night (20–2 h) and early morning (6–8 h). This growth window corresponded to rainy periods with VPD below a minimum threshold associated with summer storms. Latewood IADFs are produced in response to these wet late-summer conditions, which could be related to bimodal growth. These associations are in line with correlations showing that high minimum (night) rather than maximum (day) temperatures reduce growth. This last idea should be further checked in drought-prone forests using global tree-ring databases.

Heat transfer reduction in building envelope with green façade system: A year-round balance in Mediterranean climate conditions

This study focuses on the thermal behaviour of a building prototype equipped with an evergreen green façade. The results of a two-year experimental campaign carried out under Mediterranean climate conditions are presented. Heat fluxes in the green covered wall and in the bare wall were analysed. Their comparison allowed finding out the energy saving, in terms of heat flux reduction through the wall, obtained through the use of the green façade. The energy benefit was evaluated throughout the year, differences between warm and cold periods and between times of day were pointed out. In the warm periods, energy saving was recorded mainly at daytime, while in the cold periods at night-time. The evergreen green façade allowed remarkable energy saving in wintertime as well. The monthly mean energy saving resulted equal to 8.19 MJ m−2. The maximum benefit was achieved in July, 17.24 MJ m−2, while the minimum in January, 2.33 MJ m−2. The green façade provided an annual energy saving equal to 28.5 % compared to the un-vegetated wall.