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This paper explains and analyses a virtual gamification experience developed by a teaching group from the University of Catania (Italy) and the University of Cordoba (Spain). A competition based on professional tasks about hydrological planning was implemented in two subjects on Hydrological Sciences. The teaching experience was designed to improve the acquisition of technical knowledge and skills needed for hydrological studies, promote the management of ICT and increase international cooperation between different universities; all aimed at making students more employable. The experience is transferable to different academic levels. Following the philosophy of soccer leagues, the students solved and presented the exercise by teams of two students. Through videoconference, the presentation and the explanation were done so the fans in each country supported their teams. The students found it a very challenging experience but at the same time, some of them were aware of their needs of improving technical knowledge, particularly Geographical Information Systems, and English language skills. Updating of tools and the schedule within the different academic calendar were their main organization handicaps. The main outcome of the presented experience is that social energy and enthusiasm associated to popular activities such as soccer led to improve the interest and the motivation of the students in challenging technical contents as well as teamwork and language transversal competences.

Increasing the economic and environmental sustainability of irrigated agriculture is a vital challenge for the Mediterranean crop production sector. This study explores the effects of the adoption of reclaimed water (RW) as source of irrigation in conjunction with the application of deficit irrigation strategies in an olive orchard (different genotypes) located within the "Valle dei Margi" farmhouse (Eastern Sicily). Specifically, the RW was obtained in situ by treating the wastewater coming from the farmhouse throughout a nature-based treatment wetland system (TW). The effects of RW on crop water status (CWS) was assessed by conducting plant-based measurements (i.e., leaf water potential, Ψ; and leaves' relative water content, RWC) and determining satellite-based biophysical indicators. An economic and environmental evaluation of the proposed sustainable irrigation practices was carried out using the life cycle assessment (LCA) approach. The RW quality showed high variability due to fluctuations in the number of customers at the farmhouse during the COVID-19 pandemic period. A strong impact on the variation in Ψ was observed among the olive orchard under the different water regimes, evidencing how CWS performances are conditioned by the genotype. However, no differences in leaves' RWC and in satellite-based biophysical indicators were detected. Finally, the results of the LCA analysis underlined how the use of RW may permit us to obtain important economic and environmental gains, representing an added value for olive growing for operating in accordance to more sustainable development models. [ABSTRACT FROM AUTHOR]

The use of citrus waste (peel, CW) as organic fertilizer was investigated on soil microbiota and on soil physico-chemical and hydraulic characteristics. The biotic components on CW and the effect on nutritional status, leaf chlorophyll content, fruit set and production of "Tarocco" orange trees were also identified. The citrus waste was supplied to an experimental orchard at different doses: 45 kg m−2 (with and without Ca(OH)2 addition) and 90 kg m−2. The study was conducted in three consecutive years (2015–2017) on 20-year old orange trees at the experimental farm of the University of Catania (Italy). The main results of the study confirm that the use of CW as a biofertilizer offers a great opportunity for sustainable sweet orange production. [ABSTRACT FROM AUTHOR]

The effect of four different irrigation levels on the marketable yield and economic return of summer-growth lettuce was evaluated during 2005 and 2006 in Eastern Sicily, Italy. The viability of deficit irrigation was evaluated by estimating optimum applied water levels. Actual evapotranspiration ([ET.sub.0]) was estimated by combining pan evaporation measures and the Penman-Monteith approach ([ET.sub.0-PM]). The highest marketable yield of lettuce was recorded for plots receiving 100% [ET.sub.0-PM]. For deficit irrigated plots, reductions in crop production were ascribed to a decrease in lettuce weight. Crop coefficients equal to 1 determined maximum crop production values. Crop water use efficiency was maximum at a 100% [ET.sub.0-PM] level of water applied, corresponding to yield of 0.3 t [ha.sup.-1] [mm.sup.-1]. Irrigation water use efficiency reached its maximum at a 40% [ET.sub.0-PM] level, with values of 0.54 and 0.44 t [ha.sup.-1] [mm.sup.-1] during 2005 and 2006, respectively. Water applied and marketable yield of lettuce showed a significant quadratic relationship. Cost functions had a quadratic form during 2005 and a linear form during 2006. In the land-limiting condition the optimal economic levels fit the agronomic ones well. In the water-limiting condition, ranges of water deficit of 15-44% and 74-94% were as profitable as full irrigation, thus contributing to appreciable water savings. DOI: 10.1061/(ASCE)0733-9437(2008)134:4(437) CE Database subject headings: Economic factors: Evapotranspiration; Irrigation scheduling: Water management; Crops; Italy.

Crop evapotranspiration ([ET.sub.c]) and crop coefficient ([K.sub.co]) values of four clean-cultivated navel-orange orchards that were irrigated with microsprinklers, having different canopy features (e.g., age, height, and canopy cover) were evaluated. Half-hourly values of latent heat flux density were estimated as the residual of the energy balance equation using measured net radiation ([R.sub.n]), soil heat flux density (G), and sensible heat flux density (H) estimated using the surface renewal method. Hourly means of latent heat flux density (LE) were calculated and were divided by the latent heat of vaporization (L) to obtain ETC. Crop coefficients were determined by calculating the ratio [K.sub.co]=[ET.sub.c]/[ET.sub.o], with reference evapotranspiration ([ET.sub.o]) determined using the hourly Penman-Monteith equation for short canopies. The estimated [K.sub.co] values ranged from 0.45 to 0.93 for canopy covers having between 3.5 and 70% ground shading. The [K.sub.co] values were compared with KC values from FAO 24 (reported by Doorenbos and Pruitt in 1975) and FAO 56 (reported by Allen et al. in 1998) and with [K.sub.c] values from research papers that estimated reference ET from pan evaporation data using the FAO 24 method. The observed [K.sub.co] values were slightly higher than [K.sub.c] values for clean-cultivated orchards with high-frequency drip irrigation in Arizona and were slightly lower than for nontilled orchards in Florida. The K,.o values were considerably higher than [K.sub.c] values from FAO 24 and FAO 56 and were higher than [K.sub.c] values from border-irrigated orchards near Valencia, Spain. CE Database subject headings: Evatranspiration; Crops; Coefficients; Irrigation.

Photosynthetically active radiation (PAR) intercepted by orange orchards (Frost Nucellar navel) having different canopy sizes was measured to determine the relationships with crop coefficient ([K.sub.co] and [K.sub.cr]) values and crop evapotranspiration (ET) ([ET.sub.c]). Three separate experiments were carried out near Lindsay, Calif. during the months of July and August 2004 to compute the fraction of light PAR intercepted by mature and immature orange orchards. Periodic readings of PAR data were compared with near simultaneous measurements of net radiation [R.sub.n] (mV), heat transfer through exposed flux plates [F.sub.h] (mV), and incident total solar radiation [R.sub.s] (mV). The PAR data were used to calculate canopy light interception and the results were compared with those computed from the [F.sub.h] and [R.sub.s] data. The other sensors were studied as possible substitutes for the more expensive PAR light bar. Light interception by the different canopies was related to crop coefficient ([K.sub.co] and [K.sub.cr]) values that were determined by micrometeorological measurement of [ET.sub.c] and Penman-Monteith reference evapotranspiration [ET.sub.o] and [ET.sub.r]. CE Database subject headings: Evapotranspiration; Crops; California; Irrigation; Measurement; Light, natural; Radiation.

Crassulacean acid metabolism (CAM) crops are important agricultural commodities in water‐limited environments across the globe, yet modelling of CAM productivity lacks the sophistication of widely used C3 and C4 crop models, in part due to the complex responses of the CAM cycle to environmental conditions. This work builds on recent advances in CAM modelling to provide a framework for estimating CAM biomass yield and water use efficiency from basic principles. These advances, which integrate the CAM circadian rhythm with established models of carbon fixation, stomatal conductance and the soil–plant‐atmosphere continuum, are coupled to models of light attenuation, plant respiration and biomass partitioning. Resulting biomass yield and transpiration for Opuntia ficus‐indica and Agave tequilana are validated against field data and compared with predictions of CAM productivity obtained using the empirically based environmental productivity index. By representing regulation of the circadian state as a nonlinear oscillator, the modelling approach captures the diurnal dynamics of CAM stomatal conductance, allowing the prediction of CAM transpiration and water use efficiency for the first time at the plot scale. This approach may improve estimates of CAM productivity under light‐limiting conditions when compared with previous methods. This work uses a mathematical description of the CAM circadian rhythm to predict CAM biomass accumulation and transpiration in the field. Results are compared with data from field experiments and predictions from the environmental productivity index for Opuntia ficus‐indica and Agave tequilana. [ABSTRACT FROM AUTHOR]

The study evaluates the accuracy of measured and estimated crop evapotranspiration fluxes (ETc) on Citrus in a semiarid Mediterranean climate (Sicily, Italy). Specifically, ETc rates derived from in situ techniques [eddy covariance (EC) and sap flow heat pulse velocity (HPV)] and modelling approaches [Food and Agricultural Organization of the United States (FAO) Irrigation and Drainage Paper No. 56 (FAO-56) single and dual crop coefficient (Kc)] were compared under deficit irrigation scenarios. Results of the comparison showed that the single and dual Kc approaches provided similar ETc estimates (292 and 324 mm), even if these approaches overestimated ETc measured by EC (ETEC) (17% and 30% respectively). HPV was able to show transpiration (T) reductions caused by deficit irrigation strategies when compared with T under full irrigation condition (ranging from 70% to 82%). Overall, the assessed methodologies were able to capture ETc trends, but the selection of the most appropriate one will depend on the specific crop and study site characteristics. [ABSTRACT FROM AUTHOR]