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Homestead aquaponic production has been proposed as a reasonable alternative for obtaining food within the framework of the circular economy. However, little is known about the ability of homestead aquaponics to contribute to a healthy diet and the savings it represents on the cost of such diets for inhabitants of economically depressed communities. In the present work, based on a case study, the nutritional contribution of vegetables and fish produced in one year has been calculated, with the goal of determining the contribution of aquaponics to the healthy diet of an adult during this study period. The amount of external food products that should be purchased, the nutritional contribution of the complete diet (comparing it with that of a Mediterranean diet), and its cost have also been determined. The results show that achieving a balanced diet in macronutrients, minerals and essential nutrients with aquaponics is feasible, with a real cost of about 3.07 euros per person per day, amounting to a mean savings of 22% compared to the market price of food. The percentage of nutrient contribution of aquaponic foods exceeds in most cases 20%, being especially high for protein, dietary fiber, some minerals such as potassium, and vitamins. [ABSTRACT FROM AUTHOR]

The lack of space in cities has favoured the development of vertical gardens in indoor and outdoor environments. For an adequate development and appearance of the plants in these living walls, it is necessary to provide nutrients (usually by means of fertigation). One of the main limitations is the difficulty in obtaining a uniform distribution of nutrients, especially in felt systems. The objective of this research was to identify whether the distribution of nutrients (particularly iron and phosphorous) applied by fertigation in a felt living wall depended on the species used and the location of the plants in height. Three modules of a Fytotextile® felt-based living wall were used, each module containing three columns of different species: Soleirolia soleirolii, Philodendron hederaceum, and Nephrolepis exaltata. Fertigation was applied using a Hoagland–Arnon solution for 4 months. Measurements of leaf area, normalised difference vegetation index (NDVI), chlorophyll meter readings (CMR), fresh and dry weight, and P and Fe concentration were carried out for each of the plants. Comparing variables within the same species at different heights showed no significant differences in the variables. This means that the distribution of nutrients along the living wall (especially in height) was uniform. It is important to note that these results could vary for other types of living walls or for other configurations of the fertigation system. [ABSTRACT FROM AUTHOR]

Twenty years after the Bologna Declaration and a decade after Spanish university engineering degrees were updated to comply with the European Credit Transfer System (ECTS), there is still uncertainty on the degree of adaptation to the ECTS system of the final degree project (FDP) course in engineering programs, especially in terms of the workloads allocated to students. The inherent characteristics of the FDP course, with all the learning activities of an unstructured nature, make the real student workload as well as that of the FDP teachers very uncertain. This study addresses this issue by (1) identifying the nature of the unstructured student learning activities related to the FDP course, (2) measuring the time spent by students in the different FDP learning activities throughout the course, and (3) measuring the workload of FDP teachers. A user-friendly smartphone application was configured so that students and teachers in the agricultural engineering degree program at the University of Seville registered the time spent daily on each of the identified FDP learning (students) and supervising (instructors) activities. The results showed that the reported FDP workloads by students who passed the FDP course in either of the two exam periods of the academic year were not significantly higher than the nominal ECTS credit hours stipulated for the FDP course. The FDP teachers reported notably higher workloads than those stipulated by the university regulations. No significant correlation was found between student workload and FDP scores. [ABSTRACT FROM AUTHOR]

• Three substrates (expanded clay, perlite and pumice) tested in six living wall modules. • Water consumption and plant development were monitored using two ornamental species. • All substrates showed to be suitable for living walls. • Most of the differences observed were due to the lighting conditions. • Pumice showed a slightly better performance in green cover and biomass production. Vertical greening systems for buildings are becoming common in many cities. There are different options in the market but some types of living walls require the use of inorganic substrates as plants are grown in a hydroponics culture. In this study, three different substrates (expanded clay, perlite and pumice) are tested in six living wall modules (two per substrate) with two lighting conditions. The substrates were physically and chemically characterized and both water consumption and plant development (green cover, flowering, biomass production and photosynthetic activity) were monitored in two different tests. The three substrates showed to be suitable for living walls and most of the differences observed were due to the lighting conditions. Among the three substrates assessed, pumice exhibited a slightly better performance in terms of green cover and biomass production. [ABSTRACT FROM AUTHOR]

• Small-scale aquaponic production of lettuce and goldfish is evaluated. • Three hydroponic sub-systems tested: NFT, floating raft, vertical felt. • NFT showed the best performance both in terms of crop production and water consumption. • Floating raft and vertical felt systems had poor crop production. • No big differences found in fish growth. Aquaponics is a developing technique that combines the simultaneous production of plants (hydroponics) and fish (aquaculture). With it, the use of resources (i.e., water, nutrients, land) is reduced whilst at the same time minimising residues' discharge to the environment. Among its benefits, it allows the production of healthy vegetables and fish in reduced spaces by means of small-scale systems. In this work, three of them based on FAO models with different hydroponic subsystems (nutrient film technique -NFT-, floating raft, and vertical felt) are tested to produce lettuce (Lactuca sativa) and goldfish (Carassius auratus). Water parameters as well as the growth of plants and fishes were monitored in two different production cycles. The hydroponic subsystem that outperformed the best was the NFT, both in terms of crop production and water consumption. All systems showed similar results in fish production. Further research is needed to corroborate the outputs obtained when using other combinations of plants and fishes. Small-scale aquaponic systems are particularly interesting for self-production and even more so in urban environments with reduced available space. [ABSTRACT FROM AUTHOR]

Urban development is causing environmental and social concerns that are compromising human welfare and the sustainability of cities. New urban greening concepts are being developed to mitigate these problems in a sustainable and natural way. Vertical greening systems can be defined as structures that allow vegetation to spread over a building facade or interior wall. These systems are becoming popular though they are still evolving and more knowledge on some of their particular impacts is required. In the last five years, the number of studies published in the scientific literature on this topic, especially involving living walls, has significantly increased. This scientific interest has corresponded with an increased and parallel attention by the general public. This work offers a broad description of the different systems and a comprehensive review of the particular benefits of these green infrastructures. Knowledge gaps and shortcomings have also been identified and discussed. [ABSTRACT FROM AUTHOR]

Many pumps are used for irrigation in central California, but a great number of them are operating inefficiently. In this paper, the information recovered from over 15,000 electric irrigation pump tests in central California is analyzed. The objectives of this study are to define the common characteristics attributed to pumps with best and worst performance and to identify the possible target groups that might benefit from improvements, obtaining potential energy savings. The results showed that pumps with lower reported total dynamic head (TDH) and flow rate () usually have poorer overall pumping plant efficiency (OPPE) values, but high flow rates and input power are typically associated with better OPPE values. According to this analysis, energy savings of more than could be achieved for well pumps, with a per-pump average of . For non-well pumps, the total potential savings are and the average per pump is . [ABSTRACT FROM AUTHOR]

Poor indoor quality affects people's health and well-being. Phytoremediation is one way in which this problem can be tackled, with living walls being a viable option for places with limited space. The aim of this study was to evaluate the efficiency of five plant species in a living wall to remove Volatile Organic Compounds (VOCs) and to identify whether the type of pollutant has any influence. An enclosed chamber was used to add the contaminants n-hexane and formaldehyde independently. Total VOCs were measured for three days in two scenarios: (1) empty chamber, and (2) chamber with living wall. Five living walls were prepared, each with three plants of the same species: Spathiphyllum wallisii, Philodendron hederaceum, Ficus pumila, Tradescantia pallida, and Chlorophytum comosum. There was no correlation between leaf area/fresh weight/dry weight and the contaminant reduction. In general, all five species were more efficient in reducing TVOCs when exposed to formaldehyde than to n-hexane. Chlorophytum comosum was the most efficient species in reducing the concentration of TVOCs for both contaminants, Spathiphyllum wallisii being the least efficient by far. [ABSTRACT FROM AUTHOR]

Aquaponics involves the simultaneous production of plants and fish and it is increasingly being used with a self-consumption purpose. However, there are uncertainties and little information about the economic sustainability of small-scale self-managed aquaponic systems. The objective of this study was to obtain economic information about these systems, including the level of commoditization of food production as a measure of their autonomy. For this purpose, two small-scale aquaponic systems (SAS) based on FAO models were self-constructed using cheap and easy-to-obtain materials and monitored for a year. A total of 62 kg of tilapia and 352 kg of 22 different vegetables and fruits were produced, with an average net agricultural added value of 151.3 €. Results showed positive accounting profit but negative economic profit when labor costs were included. The degree of commoditization was around 44%, which allows a certain autonomy, thanks to the use of family labor force. [ABSTRACT FROM AUTHOR]

Aquaponic facilities allow the joint production of fish and plants in a reduced space. This hydroponic technique, combined with vertical farming, is not well studied. The main objective of this work was to compare basil production between horizontal and vertical decoupled aquaponic systems and assess the utilization of supplemental lighting in a greenhouse environment. Six independent vertical racks were arranged with hydroponic trays at three heights. Three racks were affixed with LED lighting on the lowest levels and three with supplemental lighting on the intermediate level. Immediately adjacent to the vertical systems, two independent horizontal systems containing three trays were constructed to compare basil production. After 35 days of growth post transplanting, the total production per tray and weight, height, number of leaves, and nodes of 20 selected plants per tray were determined. Records of the intensity of illumination photosynthetic photon flux density (PPFD)) were recorded at dawn (8:00), noon (12:00), and dusk (18:00) at randomly predetermined positions associated with the 20 selected plants per tray. The total basil production in the experiment was 58.79 kg, with an average production per unit area of 2.43 and 0.94 kg m−2 for vertical and horizontal systems, respectively. Productivity per unit area in the vertical systems was 160% greater than in horizontal systems. A significant effect of lighting, the height of the tray, and plant position inside the tray was found on plant growth parameters. Optimization of light source distribution and tray orientation can enhance the productive performance in vertical aquaponic systems. Electricity cost associated with supplemental lighting per kg of production increment was 21.84 and 12.25 $ kg−1 for the bottom and intermediate levels of the vertical system, respectively, the latter being economically the most profitable. [ABSTRACT FROM AUTHOR]

• The recovery capacity of 'Tifway' bermudagrass to summer drought is assessed. • Different durations (3, 5, 8 and 10/11 weeks) of the drought period were employed. • Green cover and visual turf quality were monitored. • Drought periods longer than 5 weeks did not allow reaching 50% of green cover. Water management constitutes one of the main challenges for turfgrass growing in arid and semi-arid regions, exacerbated when the conditions under which the turfgrass is cultivated are limiting (e.g., sandy shallow soils with low maintenance). The objective of this study has been to evaluate the recovery of Tifway [ Cynodon dactylon (L.) Pers. × Cynodon transvaalensis (Burtt-Davy)] bermudagrass when grown on a 10-cm sandy soil rootzone and under low-maintenance management (i.e., reduced fertilization) after varying periods of summer drought. Turfgrass assessment was performed by monitoring the green coverage and quality attributes during the recovery period. The duration of the drought was found to be determinant for the recovery capacity of Tifway bermudagrass. Summer drought periods longer than 5 weeks did not allow reaching at least 50% of the green coverage. The soil depth and type were shown to be limiting factors of the recovery capacity from drought of Tifway bermudagrass, as can be seen from a comparison with other data found in the literature for the same species/cultivar. The data collected in order to monitor the performance of the turfgrass (green cover and visual quality) using Digital Image Analysis and Normalized Difference Vegetation Index were very similar to those obtained by traditional observation methods, reducing labor hours. [ABSTRACT FROM AUTHOR]

• Three kind of vegetables (romaine lettuce, Swiss chard, and curly kale) grown in an aquaponic system. • Their aptitude for consumption in terms of nitrate levels in leaves is determined. • Low levels in lettuce (613 mg kg−1), higher in chard and kale (2388 and 1425 mg kg−1). • The nitrate content observed are below the limits stipulated in the existing legislation. • Values inside the range of those of the same vegetables grown in a conventional way. Aquaponics is a farming technique that can be used in urban environments for the simultaneous production of plants (hydroponics) and fish (aquaculture). The fish consume the supplied feed and their waste is naturally converted to nitrate and other nutrients, which are then taken up by the plants, acting as a natural water filter. Regarding food safety, there is concern about nitrate accumulation in leafy vegetables produced using this technique. In this study, three different species are tested using a small-scale aquaponic system in order to determine if they are apt for consumption in terms of nitrate levels in their leaves. The nitrate contents observed (613, 2387.8 and 1425.4 mg kg−1 for romaine lettuce, Swiss chard and curly kale, respectively) are below the limits imposed by the European Commission in the existing regulations. They are also within the range of values obtained for the same vegetables cultivated in a conventional way. [ABSTRACT FROM AUTHOR]

• Six commercial LED lighting systems are tested for indoor living walls. • All the lamps tested but one proved to be apt for their use to light living walls. • They showed a favourable performance in terms of biomass production and green cover. • Their placement, beam angle and lamp orientation play an important role. • Aesthetics and viewers' preferences were also studied. Building-integrated vegetation systems, such as living walls (LW), are becoming common tools for improving the sustainability of cities as well as an aesthetic resource. When used indoors, LW usually require a lighting system to ensure both an adequate plant development and a correct appearance. In this study, six commercial LED lighting systems are tested in order to assess their suitability for the proper performance of LW. The LW monitored were composed of two plant species (Soleirolia soleirolii and Spathiphyllum wallisii) frequently used in indoor LW. All the lamps tested (Aster and Dahlia of Ignia Green, Logar CMH, CLH and Forum of Lledó) proved to be apt for their use to light LW (except for the case of CF-UT01 of Panda Grow), as they showed a favourable performance in terms of plant development, with few differences between them in biomass production and green cover. The tested Aster (Ignia Green) and Logar CMH (Lledó) lamp models were not efficient for long distances between the vegetation and the light source. Despite these results, as illumination is one of the factors that determines the indoor ambience, aesthetics and viewers' preferences were also studied. According to the observers' perception, the Dahlia model (Ignia Green) was preferred by 54.4 % of the respondents, while the rest of the lamps were preferred less. [ABSTRACT FROM AUTHOR]

Aquaponics is emerging as an interesting alternative for sustainable agriculture which meets the philosophy of circular economy, decreasing not only the need of external resources but also increasing their use efficiency. Several studies can be found dealing with the analysis of different fish species combined with a great variety of crops in systems with diverse sophistication levels. Strawberry crop may be interesting for aquaponics systems. However, early production and the quality of the fruit, which are crucial factors affecting crop profitability, have not been previously assessed in aquaponics systems. This work aimed at evaluating these factors together with the consumption of resources in strawberry production using commercial multi-layer NFT channels coupled with tench production in an aquaponic system. Production of tench with low density of fish (700–1300 g m−3) was associated to 2 hydroponic lines where plants were transplanted in rockwool plugs or bare roots. Despite the fact that the transplanting of the strawberries was performed one month later than usual for this crop, the extra-early production was 31.9 and 33.6 g per plant for rockwool and bare root substrates, respectively. No significant differences were found neither in strawberry production nor in fruit quality for the two types of substrates studied. However, parameters related to earliness varied differently along time between bare root and rockwool. The cultivation of bare root plants is recommended, since it involves lower costs by saving in the acquisition of the substrate and less environmental and health problems for workers. Despite the fact that tench is a species very well adapted to the weather conditions in the production area, its low average daily gain ratios and its long growth cycle makes it unsuitable for combination with the cultivation of strawberry. However, the combination of a joint production of fish and plants in simple aquaponic systems would allow savings in fertilizer and water, within a production framework of circular economy. [ABSTRACT FROM AUTHOR]

• Two aquaponic systems for self-consumption were studied and optimized. • 62 kg of tilapia and 352 kg of vegetables, herbs and fruits were produced in 32 m2. • Thermo-solar panels and bio-fertilization alternatives contributed to save energy. • 155 % of fresh fish and 129 % of vegetables annual requirements for a 4 members family were provided. Aquaponic systems combine fish (aquaculture) and plant production (hydroponics), mimicking a complex ecosystem. Though aquaponic facilities can be built for commercial purposes, the self-consumption perspective is also important. There is a gap in studies that evaluate the use of a large number of plant species produced in aquaponic systems for self-consumption. The objective of this study was assessing the aquaponic production of a polyculture of different vegetables, herbs and fruits together with tilapia, with a self-consumption purpose, during a whole year in a marginal neighbourhood of the city of Seville (Spain), taking into account the climatic limitations during summer and winter. Two alternatives to reduce energy consumption in winter were also tested. This work provides an exhaustive description of the operation and management of two self-constructed Micro-Scale Aquaponic Systems (4.56 m2 of cropping area and a 1 m3 fish tank) based on FAO models. In them, 62 kg of tilapia and 352 kg of 22 different vegetables and fruits were produced during a year. This study proved that a micro-scale aquaponic facility can provide enough fruits, vegetables and fish for a complete family of four members throughout the year. [ABSTRACT FROM AUTHOR]