Food plants biofortification for micronutrients is a tool for the nutritional value improvement of food. Soilless cultivation systems, with the optimal control of plant nutrition, represent a potential effective technique to increase the beneficial element content in plant tissues. Silicon (Si), which proper intake is recently recommended for its beneficial effects on bone health, presents good absorption in intestinal tract from green bean, a high-value vegetable crop. In this study we aimed to obtain Si biofortified green bean pods by using a Si-enriched nutrient solution in soilless system conditions, and to assess the influence of boiling and steaming cooking methods on Si content, color parameters and Si bioaccessibility (by using an in vitro digestion process) of pods. The Si concentration of pods was almost tripled as a result of the biofortification process, while the overall crop performance was not negatively influenced. The Si content of biofortified pods was higher than unbiofortified also after cooking, despite the cooking method used. Silicon bioaccessibility in cooked pods was more than tripled as a result of biofortification, while the process did not affect the visual quality of the product. Our results demonstrated that soilless cultivation can be successfully used for green bean Si biofortification.

To address sustainability challenges, agricultural advances in Mediterranean horticultural systems will necessitate a paradigmatic shift toward smart technologies, the impacts of which from a life cycle perspective have to be explored. Using life cycle thinking approaches, this study evaluated the synergistic environmental and economic performance of precise irrigation in greenhouse Zucchini production following a cradle-to-farm gate perspective. A cloud-based decision support system and a sensor-based irrigation management system (both referred to as “smart irrigation” approaches) were analyzed and compared to the farmer’s experience-based irrigation. The potential environmental indicators were quantified using life cycle assessment (LCA) with the ReCiPe 2016 method. For the economic analysis, life cycle costing (LCC) was applied, accounting not only for private product costs but also for so-called “hidden” or “external” environmental costs by monetizing LCA results. Smart irrigation practices exhibited similar performance, consuming on average 38.2% less irrigation water and energy, thus generating environmental benefits ranging from 0.17% to 62%. Single score results indicated that life cycle environmental benefits are up to 13% per ton of product. The cost-benefit analysis results showed that even though the implementation of smart irrigation imposes upfront investment costs, these costs are offset by the benefits to water and energy conservation associated with these practices. The reduction of investment costs and higher water costs in future, and lower internal rate of return can further enhance the profitability of smart irrigation strategies. The overall results of this study highlight that smart and innovative irrigation practices can enhance water-energy efficiency, gaining an economic advantage while also reducing the environmental burdens of greenhouse cultivation in a Mediterranean context.

This study aimed to determine the effects of irrigation management based on matric potential control on growth, plant-water relations, yield, fruit quality traits and water-use efficiency of subirrigated (through bench system) soilless tomato. Tensiometers were used for automatic irrigation control. Two cultivars, ‘Kabiria’ (cocktail type) and ‘Diana’ (intermediate type), and substrate water potential set-points (-30 and -60 hPa, for ‘Diana’, and -30, -60 and -90 hPa for ‘Kabiria’), were compared. Compared with -30 hPa, water stress (corresponding to a -60 hPa irrigation set-point) reduced water consumption (14%), leaf area (18%), specific leaf area (19%), total yield (10%) and mean fruit weight (13%), irrespective of the cultivars. At -60 hPa, leaf-water status of plants, irrespective of the cultivars, showed an osmotic adjustment corresponding to a 9% average osmotic potential decrease. Total yield, mean fruit weight, plant water and osmotic potential decreased linearly when -30, -60 and -90 hPa irrigation set-points were used in ‘Kabiria’. Unmarketable yield in ‘Diana’ increased when water stress was imposed (187 vs 349 g∙plant-1, respectively, at -30 and -60 hPa), while the opposite effect was observed in ‘Kabiria’, where marketable yield loss decreased linearly [by 1.05 g∙plant-1 per unit of substrate water potential (in the tested range from -30 to -90 hPa)]. Whereas in the second cluster, fruit total soluble solids and dry matter increased irrespective of the cultivars, in the seventh cluster in ‘Diana’ only a slight increase was observed from -30 vs. -60 hPa (3.3% and 1.3%, respectively, for TSS and dry matter), while in ‘Kabiria’ the increase was more pronounced (8.7% and 12.0%, respectively, for TSS and dry matter), and further reduction in matric potential from -60 to -90 hPa confirmed the linear increase for both parameters. Both glucose and fructose increased linearly in ‘Kabiria’ fruits on decreasing the matric potential, while in ‘Diana’ there was no increase. Control of substrate water status offer the possibility to steer crop response by enhancing different crop-performance components, namely yield and fruit quality, in subirrigated tomato. Small-size fruit varieties benefit more from controlled water stress in terms of reduced unmarketable yield loss and fruit quality improvements.