Vertical Farming Research Articles

Means-end chain generation with online laddering: A study on vertical farming with consumers in Singapore and Germany

Through rapid advances, vertical farming (VF) systems are becoming an addition to conventional agricultural practices that under increasing climate stress can contribute to more sustainable food production. The present research advances extant consumer research on VF by exploring how consumers associate the different characteristics of VF with the technology’s pros and cons, and how these link to their personal values. To this end, consumers’ cognitive structures relating to VF were uncovered through means-end chains (MECs) and laddering methodology. While both soft and hard laddering approaches remain in use, innovation and methodological development are focused on hard laddering. The present research contributes to this expansion by trailing a hybrid-hard laddering approach that is suitable for online surveys and large sample sizes while incorporating some aspects of soft laddering. Participants lived in Singapore (SG) (n = 547) or Germany (DE) (n = 537) and completed the laddering task after reading an information text about VF. Data analysis resulted in hierarchical value maps (HVM) which were compared by country and groups of participants with different attitudes to VF. Both altruistic and self-centred motives were key to acceptance of VF while energy use emerged as a concern. For some consumers positive linkages were established to “pleasure and enjoyment” and this may be harnessed to enhance uptake. The hybrid-hard laddering approach was successful in so far as the results fitted expectations. However, room for improvement exists.

Sustainability Framing of Controlled Environment Agriculture and Consumer Perceptions: A Review

The ongoing criticism of conventional agricultural activities being unsustainable in the face of climate change and global population growth has been one of the key drivers for technological innovation in this space. Controlled Environment Agriculture (CEA), especially in the high-tech form of vertical farming, as a new agri-food technology, has been positioned as a sustainable solution to the dilemma of feeding the world and preserving the planet. Acknowledging sustainability as a multi-dimensional concept encompassing environmental, economic, social, and cultural aspects, this review briefly outlines the evolving meaning of sustainability, and how CEA has been framed as sustainable in the literature. Specifically, the review examines studies that have investigated consumer perceptions and acceptance of CEA and discussed how sustainability features of CEA were presented to consumers in a diverse way across these studies. The review highlights that the social and cultural dimensions of sustainability were largely neglected not only in research that focused on the development of CEA, but also in the exploration of consumers’ perceptions of CEA. A more holistic examination of the sustainability of CEA and a comprehensive understanding from consumers is important for transitioning towards more sustainable production systems enabled by new technologies such as CEA.

Microgreens for Home, Commercial, and Space Farming: A Comprehensive Update of the Most Recent Developments.

Microgreens are edible young plants that have recently attracted interest because of their color and flavor diversity, phytonutrient abundance, short growth cycle, and minimal space and nutrient requirements. They can be cultivated in a variety of systems from simple home gardens to sophisticated vertical farms with automated irrigation, fertilizer delivery, and lighting controls. Microgreens have also attracted attention from space agencies hoping that their sensory qualities can contribute to the diet of astronauts in microgravity and their cultivation might help maintain crew physical and psychological health on long-duration spaceflight missions. However, many technical challenges and data gaps for growing microgreensboth on and off Earth remain unaddressed. This review summarizes recent studies on multiple aspects of microgreens, including nutritional and socioeconomic benefits, cultivation systems, operative conditions, innovative treatments, autonomous facilities, and potential space applications. It also provides the authors' perspectives on the challenges to stimulating more extensive interdisciplinary research.

Vertical farm: prospects for achieving sustainable development goals

The objective of this study was to demonstrate the importance of the vertical farm as an alternative for the supply of food to the world population, mainly, in the countries where the scarcity of land is evident. We linked the use of the vertical farm with the objectives of sustainable developments developed by United Nations (UN) in the fight against hunger and social inequalities in the world. A search was carried out in the databases Pubmed, Web of Science and specialized sites, using the words, vertical farm, fight against hunger and food production. According to the articles found, we could conclude that the use of the vertical farm can bring great advances in improving the supply of food to the low-income population; however, there is a need for budgetary adequacy for the implementation and operation of the entire system, being that in in some cases the costs are very high. This causes a certain skepticism in its viability. The collaboration of government agencies, non-governmental organizations and private initiative with financial support for the creation of vertical farms is essential

Techno-Economic Assessment of an Office-Based Indoor Farming Unit

Decentralized, smart indoor cultivation systems can produce herbs and vegetables for fresh and healthy daily nutrition of the urban population. This study assesses technical and resource requirements, productivity, and economic viability of the “Smart Office Farm” (SOF), based on a 5-week production cycle of curled lettuce, lolo rosso, pak choi and basil at three photosynthetic photon flux density (PPFD) levels using a randomized block design. The total fresh matter yield of consumable biomass of all crops was 2.5 kg m−2 with operating expenses (without labor costs) of EUR 53.14 kg−1; more than twice as expensive compared to large-scale vertical farm and open-field cultivation. However, there is no need to add trade margins and transportation costs. The electricity supply to SOF is 73%, by far the largest contributor to operational costs of office-based crop production. Energetic optimizations such as a more homogeneous PPFD distribution at the plant level, as well as adaptation of light quality and quantity to crop needs can increase the economic viability of such small indoor farms. With reduced production costs, urban indoor growing systems such as SOF can become a viable option for supporting fresh and healthy daily nutrition in urban environments.

Does green vertical farming offer a sustainable alternative to conventional methods of production?: A case study from Scotland

AbstractClimate change is an existential global reality that is placing considerable stress on agriculture sectors. With the recognition of the impacts of climate change on food security, there has been a greater uptake of controlled environment agriculture (CEA) to provide climate‐resilient and high‐quality production. Vertical farming (VF) can allow primary production in urban locations as well as reducing seasonality and variability in produce. It is emerging as an alternative to traditional farming methods. This research aimed to explore the major environmental impacts of VF produce in comparison with conventional farming methods, using lettuce as an example crop. Life cycle analysis indicate that electricity consumption by VF account for 91% of the carbon footprint. Under the 2019 Scottish electricity mix, VF did not offer a viable competitor for UK open‐farmed lettuce or Spanish imports in terms of low greenhouse gas emissions (at approximately 1.49 kgCO2 eq. kg−1). However, with increasing use of renewable electricity in the national mix, by 2020, this had dropped to 0.42 kgCO2 eq. kg−1 making it comparable with UK open‐field agriculture (at approximately 0.46 kgCO2 eq. kg−1). Under a 100% renewable electricity generation scenario, VF‐related emissions drop further (to 0.33 kgCO2 eq. kg−1). This would potentially offer a low‐carbon production method not subject to seasonality which is better than that reported by most other production methods and offers higher water and nutrient efficiency. This research highlights green VF as potential alternative for sustainable future produce especially under changing climate scenarios.

Ozone control as a novel method to improve health-promoting bioactive compounds in red leaf lettuce (Lactuca sativa L.).

In this study, we determined the short-term effects of ozone exposure on the growth and accumulation of bioactive compounds in red lettuce leaves grown in a controlled environment plant factory with artificial light, also known as a vertical farm. During cultivation, twenty-day-old lettuce (Lactuca sativa L. var. Redfire) seedlings were exposed to 100 and 200 ppb of ozone concentrations for 72h. To find out how plants react to ozone and light, complex treatments were done with light and ozone concentrations (100 ppb; 16h and 200 ppb; 24h). Ozone treatment with 100 ppb did not show any significant difference in shoot fresh weight compared to that of the control, but the plants exposed to the 200 ppb treatment showed a significant reduction in fresh weight by 1.3 fold compared to the control. The expression of most genes in lettuce plants exposed to 100 and 200 ppb of ozone increased rapidly after 0.5h and showed a decreasing trend after reaching a peak. Even when exposed to a uniform ozone concentration, the pattern of accumulating bioactive compounds such as total phenolics, antioxidant capacity and total flavonoids varied based on leaf age. At a concentration of 200 ppb, a greater accumulation was found in the third (older) leaf than in the fourth leaf (younger). The anthocyanin of lettuce plants subjected to 100 and 200 ppb concentrations increased continuously for 48h. Our results suggest that ozone control is a novel method that can effectively increase the accumulation of bioactive compounds in lettuce in a plant factory.

Urban vertical farming with a large wind power share and optimised electricity costs

Producing food in an environmentally sustainable way for the growing human population is a challenge to the global food system. Vertical farm (VF) as a part of the solution portfolio is attracting interest since it uses less water, pesticides, and land which are scarce in many parts of the globe. Despite these positive factors, the energy demand for vertical farms is high, and farms often remain separate and excluded from cities where most of the population lives. City-level energy system solutions exist to empower energy efficiency and increase the share of variable renewable energy sources, but their potential has not yet been estimated for an urban energy system that includes large vertical farms. Accordingly, in this study, we simulate an urban energy system that practices vertical farming with large-scale variable renewable energies and flexibility measures. For the first part of the study, we modelled a vertical farm's energy system with demand response control to maximize electricity cost savings. To evaluate the potential of demand response, the analysis is carried out for different crops (lettuce, wheat, and soybean), and different electricity price profiles. The result of demand response control can be a reduction of 5% to 30% in electricity consumption costs. Further, sensitivity analyses highlight the effect of electricity price variations and photoperiod on demand response outcomes. In the second part, the operation of an urban energy system (Helsinki, Finland) with vertical farms was analysed through two different scenarios. These scenarios represent the emission-free Helsinki energy system in 2050 with large-scale wind power implementation. As VFs can use electricity outside the peak demand hours, the inclusion of VF with the right energy system configuration can improve the power consumption within the system by up to 19%. Further, we show that connection to the exogenous power market is important to support vertical farming in the future energy systems. In this study, key points in the integration of VF in urban energy systems are highlighted, including the role of exogenous power markets, the potential for increasing local energy consumption with large wind power, and the importance of crop selection in reducing VF's energy costs through demand response. In a city-level solution with a high wind power share, we thus recommend including a vertical farm side by strong sectoral coupling as part of the future design to maximise local consumption.

Performance analysis of hydroponic system on verticulture technique of spinach (Ipomoea aquatica)

Verticulture technique is a stratified plant cultivation system carried out vertically, either outdoors or indoors. The vertical cultivation system aims to overcome the decline in paddy fields due to the conversion of land to non-agricultural land. This vertical technique is very suitable for narrow land because it does not take up much space. Verticulture or vertical farming has three techniques, namely Hydroponics, Aquaponics, and Aeroponics. Hydroponic plant cultivation with a tower system is in great demand at this time, because the tower used a vertical pipe with water dripping from the top of the tower. Some of the nutrients are absorbed by plants through the roots and some fall to the bottom of the tower which then returns to the storage container, and is ready to be pumped back to the top of the tower. Tower hydroponics has the advantage that on 1 m2 land with a tower height of 1.5 m we can plant 50-80 plant stems, whereas with the usual method only 25-30 plant stems are obtained. This study aims to design and technical test of a hydroponic system with verticulture techniques on spinach. The design results show that with an area of 3 x 2.5 m2, it has 24 towers and 624 plant holes. Each plant hole has 4-6 plant stems. spinach can grow perfectly compared to control plants. The results of these studies indicate that this system is very suitable for a narrow area.

Technology Dissemination of Backyard Farming for Supporting Food Security in Palu Central Sulawesi

The optimally of the backyard provide enormous benefits to support the nutritional needs of the family. It is one of strategies in gaining food security in the household and supporting the environment sustainability. The study was conducted in Palu Central Sulawesi in October 2021 as an evaluation survey of the technology dissemination for backyard optimization. The data were analyzed by Expected Food Pattern and scoring method for transferred technologies. The result shown that the technology dissemination increase the Food Pattern Expectation score from 74.2 to 78.0 and increase the family income up to 23%. The technologies’s implementation score consist of 20% in vertical farming, 27% in soil block nursery, 27% in the composition of planting media, 33% in nature pesticide, 27% in MOL production, and 20% in household waste composting. To increase the technology adoption, an assistance for the groups as a model and deployment for larger target are needed.

Unified modeling of unconventional modular and reconfigurable manipulation system

Customization of manipulator configurations using modularity and reconfigurability aspects is receiving much attention. Modules presented so far in literature deals with the conventional and standard configurations. This paper presents the 3D printable, light-weight and unconventional modules: MOIRs' Mark-2, to develop any custom `n'-Degrees-of-Freedom (DoF) serial manipulator even with the non-parallel and non-perpendicular jointed configuration. These unconventional designs of modular configurations seek an easy adaptable solution for both modular assembly and software interfaces for automatic modeling and control. A strategy of assembling the modules, automatic and unified modeling of the modular and reconfigurable manipulators with unconventional parameters is proposed in this paper using the proposed 4 modular units. A reconfigurable software architecture is presented for the automatic generation of kinematic and dynamic models and configuration files, through which, a designer can design, validate using visualization, plan and execute the motion of the developed configuration as required. The framework developed is based upon an open source platform called as Robot Operating System (ROS), which acts as a digital twin for the modular configurations. For the experimental demonstration, a 3D printed modular library is developed and an unconventional configuration is assembled, using the proposed modules followed by automatic modeling and control, for a single cell of the vertical farm setup.

Switched Beam Array Antenna Optimized for Microwave Powering of 3-D Distributed Nodes in Clustered Wireless Sensor Network

The IoT applications like smart warehouse, smart industry, and smart vertical farming will require microwave power transmission (MPT) to the densely deployed low-power sensor nodes in 3-D space. To address this issue, a switched beam array antenna (SBA) is synthesized as an MPT system to power the proposed 3-D clustered wireless sensor network (WSN). The 3-D space is divided into nine clusters; each illuminated individually with RF power using a dedicated patch antenna subarray. The subarrays can be switched ON or OFF based on the energy requirement of the WSN cluster nodes resulting in efficient power transmission. Moreover, the low complexity of switched beam design reduces the cost and processing overhead as compared to the exiting adaptive beamforming systems in a dense WSN scenario. The subarray size and excitation coefficients are optimized with a constraint over the harvested dc power ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{dc}$ </tex-math></inline-formula> ) to enhance the 3-D coverage. In addition, the optimal location of the cluster head (CH) is evaluated to minimize the average power consumption of WSN cluster. The subarrays are designed and fabricated with the evaluated excitation coefficients, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{dc}$ </tex-math></inline-formula> measurements are carried out validating analytical results.

The role of aeroponic container farms in sustainable food systems – The environmental credentials

Sustainable food production and consumption are key to face the current climate and environmental crisis, hence innovation to produce food with lower impacts are taking more attention. Controlled environment agriculture, also known as vertical farming, is seen as one innovative approach to reduce impacts of producing food while also improving food security. Aeroponic is one of such innovations, which environmental impacts have not been well understood yet. Therefore, this study assesses the environmental impacts of aeroponic farm container system in the UK, including a full set of 19 indicators. The results show that energy requirements drive all the impacts, with climate change estimated at 1.52 kg CO2eq. per 1 kg of microgreens (pea shoots) using 2021 UK grid. Renewable powered systems improve almost all the impacts, with climate change reduced by up to 80 %, making this system competitive with conventional agricultural systems. This study proves that aeroponic farm container could offer lower impact food than equivalent imported to the UK, and that also could improve food security in terms of availability, stability, and access to food. Affordability issues need to be assessed in future work.

Influence of Pulsed, Scanning and Constant (16- and 24-h) Modes of LED Irradiation on the Physiological, Biochemical and Morphometric Parameters of Lettuce Plants (Lactuca sativa L.) while Cultivated in Vertical Farms

In city farming, when growing green crops, a significant part of the production cost is the cost of electricity for lighting. The physiology, biochemistry, morphology and productivity of plants can be affected by changing irradiation modes and these changes reduce electricity costs. However, the results of studies in the literature are contradictory. In this work, we investigated the effect of impulse (frequency 1000 Hz and duty cycle 67%), scanning (the principle of running lights) and constant 16 h and 24 h modes of operation of white light LED irradiators on the physiological, biochemical and morphometric parameters of lettuce with red and green leaves. The daytime integral of light in all variants remained unchanged ~15.6 mol m−2 day−1. Daily electricity consumption also did not differ significantly. Plants were grown on racks in a climatic chamber up to 35 days of age. For lettuce with red leaves, the most optimal for biomass accumulation and synthesis of anthocyanins was the impulse illumination mode, while for lettuce with green leaves, no statistically significant differences in biomass were observed under different irradiation modes. For red-leaved lettuce, it was found that the highest concentration of carotenoids in the leaf was observed under constant (24 h) and scanning irradiation, which is associated with a more active reaction of the photosynthetic system to prolonged irradiation and increased intensity during scanning irradiation. Also, increased photosynthetic activity was found in both varieties of lettuce at 16 h of operation of LED irradiators, which, however, did not affect their final productivity. The results may be useful for the development of LED illuminators for use in rack growing.

Upcycling Polystyrene.

Several environmental and techno-economic assessments highlighted the advantage of placing polystyrene-based materials in a circular loop, from production to waste generation to product refabrication, either following the mechanical or thermochemical routes. This review provides an assortment of promising approaches to solving the dilemma of polystyrene waste. With a focus on upcycling technologies available in the last five years, the review first gives an overview of polystyrene, its chemistry, types, forms, and varied applications. This work presents all the stages that involve polystyrene's cycle of life and the properties that make this product, in mixtures with other polymers, command a demand on the market. The features and mechanical performance of the studied materials with their associated images give an idea of the influence of recycling on the structure. Notably, technological assessments of elucidated approaches are also provided. No single approach can be mentioned as effective per se; hybrid technologies appear to possess the highest potential. Finally, this review correlates the amenability of these polystyrene upcycling methodologies to frontier technologies relating to 3D printing, human space habitation, flow chemistry, vertical farming, and green hydrogen, which may be less intuitive to many.

Unravelling Ideas and Artefacts

Abstract This study tracks the progression of students’ ideas by understanding how ideas are adopted or rejected. Understanding the discourses that lead to idea progression could help illumine sense-making and decision-making processes within student group discussions. Student-generated artefacts in the form of vertical farming prototypes were analysed. These artefacts were from four groups of students who were engaged in an integrated STEM activity to improve existing vertical farming solutions in land-scarce Singapore. In the authors’ analysis to understand how the final prototype came to being, they examined the progression of ideas through lesson phases of envisioning, sketching, collaborative modelling, feedback, and evaluation. A coding scheme was used to track whether ideas were rejected, improved, or assimilated in the final prototype. Idea maps were generated to track key developments of ideas. The findings revealed that groups that took greater risks in generating more ideas had more rejected ideas and were also more engaged in the feedback process. This resulted in richer idea development. Idea fluency was highly varied across all four groups. This suggests that group engagement and a culture of reflection and monitoring could significantly improve idea quality, although the lack of curriculum time could limit desired divergent idea generation.

The potential of urban family vertical farming: A pilot study of Shanghai

Sustainable cities are increasingly requiring local food systems. On the contrary, food self-sufficiency rate in many cities is continuously decreasing. In recent years, the concept of vertical farming (VF) has begun to show its advantages in providing a promising hope for alleviating this contradiction. However, there are few studies on the potential of VF on a city scale. This paper aims to assess the economic feasibility of an urban family vertical farming (UFVF) in Shanghai newly-built residential by modeling typical family planting mode, and using the evaluation software of vertical farms (VFer) software for calculation. Meanwhile, the influence of UFVF on the self-sufficiency rate of vegetables and fruits of households and the whole city is investigated. The results demonstrate that the UFVF contributes to increasing the self-sufficiency rate of vegetables and fruits by 20.68 % and 2.54 %, respectively, which could be important to enhance the resilience of local food system. Additionally, the return on investment of UFVF could achieve approximately 30 %. The proposed techno-economic model can assist to better predicting the small-scale VF on the urban scale, which provides a basis for decision-making on development of sustainable urban agriculture.

A systematic scoping review of the sustainability of vertical farming, plant-based alternatives, food delivery services and blockchain in food systems

Food system technologies (FSTs) are being developed to accelerate the transformation towards sustainable food systems. Here we conducted a systematic scoping review that accounts for multiple dimensions of sustainability to describe the extent, range and nature of peer-reviewed literature that assesses the sustainability performance of four FSTs: plant-based alternatives, vertical farming, food deliveries and blockchain technology. Included literature had a dominant focus on environmental sustainability and less on public health and socio-economic sustainability. Gaps in the literature include empirical assessments on the sustainability of blockchain technology, plant-based seafood alternatives, public health consequences of food deliveries and socio-economic consequences of vertical farming. The development of a holistic sustainability assessment framework that demonstrates the impact of deploying FSTs is needed to guide investments in and the development of sustainable food innovation.

Autonomous Mobile Robot with Attached Multispectral Camera to Monitor the Development of Crops and Detect Nutrient and Water Deficiencies in Vertical Farms

This study demonstrates the potential of using low-altitude multispectral imagery data to assess irrigation and fertilization techniques and the relative degree of plant water and nutrient stress. This study aims to create a methodology that can be widely used by vertical farms. Techniques were used for early water and nitrogen stress detection using multispectral reflectance systems in an indoor environment with artificial lighting. The methodology focuses on irrigation and nutrition, that sets schedules, and automatically updates a decision-making system based on crop reflectance data and simplified reflectance indices. The experimental process took place on the premises of CphFarmHouse in Denmark. The results showed that crop reflectance increased due to water and nitrogen deficiencies. The detected reflectance increase was significant on the third day of the experiment when irrigation and fertilization were not applied. It should be noted that during the experimental period, the researchers did not detect water or nitrogen deficiencies visible to the naked eye. More specifically, the Normalized Difference Vegetation Index (NDVI) and the Photochemical Reflectance Index (PRI) showed statistically significant differences between the control treatment and the two stress treatments with limited water and nitrogen. Additionally, based on the reflectance measurements and the measured physiological crop parameters, significant correlations (p &lt; 0.01) were observed mainly between the PRI and the chlorophyll content, the photosynthetic efficiency and the stomatal conductance (r = 0.84/0.90, 0.73/0.66, 0.61/0.66 among the nitrogen and water treatments). The research provides data analysis results on sensors and approaches for crop reflectance measurements as well as spectral indices for remote water and nitrogen detection. Finally, the results provide a feasibility analysis, suggesting that multispectral images could be used as a rapid tool to estimate the physiological status of plants, which is indicative of the spatial variation in the vertical farm.

Re-circulating indoor vertical farm: Technicalities of an automated duckweed biomass production system and protein feed product quality evaluation

Duckweeds are fast-growing and nutritious plants, which are gaining increased attention in different fields of application. Especially for animal nutrition, alternative protein sources are needed to substitute soybean meal. The current bottleneck is the standardized production of biomass, which yields stable quantities of a defined product quality. To solve this problem, an indoor vertical farm (IVF) for duckweed biomass production was developed. It consists of nine vertically stacked basins with a total production area of 25.5 m2. The nutrient solution, a modified N-medium, re-circulated within the IVF with a maximum flow rate of 10 L min−1. Nutrients were automatically added based on electrical conductivity. In contrast, ammonium was continuously supplied. A water temperature of 23 °C and a light intensity of 105 μmol m−2 s−1 with a photoperiod of 12:12 h were applied. During a 40-day production phase, a total of 35.6 kg of fresh duckweed biomass (equals 2.1 kg of dried product) was harvested from the IVF. On average, 0.9 kg day−1 of fresh biomass was produced. The dried product contained 32% crude protein (CP) and high levels of proteinogenic amino acids (e.g. lysine: 5.42 g, threonine: 3.85 g and leucine: 7.59 g/100 g CP). Biomass of this quality could be used as a protein feed alternative to soybean meal. The described IVF represents a modular model system for duckweed biomass production in a controlled environment and further innovations and upscaling processes.