Plant Factory: An Indoor Vertical Farming System for Efficient Quality Food Production
Abstract
Plant Factory: An Indoor Vertical Farming System for Efficient Quality Food Production provides information on a field that is helping to offset the threats that unusual weather and shortages of land and natural resources bring to the food supply. As alternative options are needed to ensure adequate and efficient production of food, this book represents the only available resource to take a practical approach to the planning, design, and implementation of plant factory (PF) practices to yield food crops. The PF systems described in this book are based on a plant production system with artificial (electric) lights and include case studies providing lessons learned and best practices from both industrial and crop specific programs. With insights into the economics as well as the science of PF programs, this book is ideal for those in academic as well as industrial settings. Provides full-scope insight on plant farm, from economics and planning to life-cycle assessment. Presents state-of-the-art plant farm science, written by global leaders in plant farm advancements. Includes case-study examples to provide real-world insights.
... For example, ideally designed vertical farming systems controlling lighting spectrum, intensity, and duration, as well as other environmental factors such as CO 2 level, air temperature, and humidity, can enhance the appearance, taste, or nutrient levels of leafy greens [5,6]. Further research has explored CEA's potential to address the food demand in urban areas while promoting sustainability [1,[7][8][9]. Industry development has been supported by multidisciplinary research focused on optimizing environmental variables to maximize yield or resource use efficiency [5,[10][11][12][13][14] and market segmentation and acceptance studies [15][16][17][18][19]. From the industry's perspective, particularly in the U.S., securing funding for capital-intensive vertical farming structures, specialized labor training, and managing high electricity consumption remain significant challenges [20]. ...
... One category of farms meeting these criteria has been named PFAL (Plant Factory with Artificial Lighting), with most PFALs located in Japan [8]. Professor Kozai is acknowledged as the leading scholar in this area. ...
... To reference land sparing here, we will focus on controlled environment agriculture that allows for growing up instead of out: IA/VF. The acreage utilized in this approach would not have to be traditionally fertile or agronomically appealing [8]. By land-sparing with high-tech farming and intensification, food systems could grow more food with fewer resources in different environments [66]. ...
Food systems around the world are challenged to meet increased demand while also mitigating ecosystem pressures from their current structure. Controlled environment agriculture (CEA) offers a potential solution to augment the food supply by adopting innovative production systems designed to overcome environmental resource limitations and efficiently serve densely populated urban areas. By utilizing Elkington’s profit, plant, and people framework (3Ps), this article assesses the sustainability of a major subcategory of CEA farms: indoor agriculture vertical farms (IA/VFs). The qualitative analysis attempts to answer the question of whether IA/VFs have fulfilled their potential. Results suggest that IA/VFs have not yet optimized their positive impact on future food system sustainability. For each of the three Ps, IA/VF’s observed progress and required breakthroughs are summarized. Notably, the financial viability of an IA/VF is more likely to be achieved through whole systems solutions: growing the right crops in the right environment, efficient use of resources, and effective consumer targeting. Significant progress is being made in the direction of innovating IA/VF’s role in future food systems. Through public–private partnerships and further analyses, further progress can be made toward realizing IA/VF’s potential to address the growing demands of an expanding world population and shrinking resource base.
... Mine drifts or tunnels (roadways) up to 3 km deep are not exposed to harsh winter climates, have stable temperatures in the range of 10 to 30℃ reliant on the locations and depths, and are suitable for vegetable growth if light is provided. Breakthroughs in light emitting diodes (LED) technology in the last decade have made it economical to use in vertical farming [3], [4]. Compared with buildings for conventional vertical farming or greenhouses, which are expensive and exposed to the surface climate, underground mines have stable environments year-round; therefore, the underground plant growing facility, i.e. underground plant factory (UGPF), could be more energy efficient. ...
... Figs. 2a, 2b and 2c show the floor plan, front cross-section view and three-dimensional model of the facility. The top 1 m is arc roof, each tier of plant growth trays is 40 cm in height [4], so a total of 9 tiers are arranged. There are 50 lettuces per square meter [25]; the growth period is 30 days, so there are 12 harvests in a year [22]. ...
... There are 50 lettuces per square meter [25]; the growth period is 30 days, so there are 12 harvests in a year [22]. The effective area ratio of total growth area for plants to the floor area is 0.87 [4], thus the total cultivation area is 4306.5 m 2 as the floor area of the growing room is 550 m 2 . There are 215,300 lettuce plants produced in one harvest and 2,583,600 lettuces produced in a year. ...
Producing leafy vegetables in plant factories (indoor vertical farming) in controlled environment provides a solution for food security to alleviate the impact of global warming and increasing extreme weather events on food production yet their high energy consumption limits the expansion of this industry. The objective of this study is to decrease energy consumption of plant factories by utilizing unused mining tunnels to house the plant factories i.e., underground plant factories (UGPF). The novelty of this research lies in the potential to reduce heating, ventilation and air conditioning (HVAC) energy consumption in controlled-environment plant production facilities by leveraging the stable thermal conditions of unused underground mine tunnels. An UGPF is conceptually designed for a northern metal mine drift and energy loads are predicted using SketchUp Plugin (geometry development software interface) and OpenStudio (building energy simulation) software packages. Due to high rock thermal conductivity (RTC) and low virgin rock temperature (VRT), high heat loss occurs through the surrounding rock envelope in the first 6 months although it gradually reduces but still significant, which reduces cooling load in light period of the UGPF. The initial (on first day) HVAC load is 28.3% lower than the surface plant factory, but with increasing operation time it increases because of reduced heat loss through rock envelope. After 3 years of operation, for the base case of 2.75 W/m.K RTC and 11°C VRT, the HVAC electricity consumption per unit cultivation area is 251 kWhe/m2.year, achieving 8.9% reduction as compared to the conventional plant factory. Sensitivity analysis shows that the light emitting diodes efficacy and photosynthetic photon flux density are dominant factors on energy load while the number of tiers is less influential considering the energy load per unit cultivation area.
... Vertical farming improves resource efficiency across land use, water, electricity, light energy, and inorganic fertilizers. Given that 70 % of global freshwater is used for agriculture, vertical farming's closed-loop water systems could alleviate water scarcity concerns and reduce unsustainable demands on land and water resources Kozai et al., 2019). ...
... Another challenge is the energy-intensive nature of maintaining optimal conditions, such as humidity, temperature, and light (Kozai et al., 2018). Strategies to reduce electricity costs include implementing energy-efficient LED lighting, designing lighting systems tailored to specific plant needs, and utilizing waste heat and renewable energy sources like solar, wind, and geothermal power (Kozai et al., 2019;Avgoustaki and Xydis, 2020). Furthermore, the range of crops suitable for vertical farming is currently limited. ...
... However, high construction costs and electricity consumption remain challenges and disadvantages for industrial promotion, especially for plant factories with artificial lighting (PFALs) [3]. For example, electricity consumption accounts for 26% of the production costs for PFALs, of which electrical light sources are responsible for 70-80% of the total energy consumption [4]. In practical production scenarios, the light use efficiency (LUE) in PFALs typically ranges from 32 to 43% of the theoretical maximum LUE [4]. ...
... For example, electricity consumption accounts for 26% of the production costs for PFALs, of which electrical light sources are responsible for 70-80% of the total energy consumption [4]. In practical production scenarios, the light use efficiency (LUE) in PFALs typically ranges from 32 to 43% of the theoretical maximum LUE [4]. There is still scope for further enhancement of the LUE in PFALs and other protected cultivation systems, especially those with supplementary light. ...
The addition of photosynthetically active radiation (PAR, 400–700 nm) with a specific quantity of far-red photons (FR, 700–750 nm) has been demonstrated to positively influence biomass accumulation and nutritional quality in greenhouse lettuce. However, current relevant studies seldom consider comprehensive and systematic comparisons of the efficacy of different approaches: substitution versus supplementation. The present work aimed to compare the two aforementioned strategies, evaluate how they impact plant growth, development and metabolic processes, and analyse the light use efficiency. In this study, loose-leaf lettuce (cv. ‘Dasusheng’) grown in a glass Venlo-type greenhouse was exposed to six supplementary light treatments, including white-red (WR) light-emitting diodes (LEDs), FR LEDs, and WR plus FR LEDs [WR130 + FR30 (the number was the photon flux density provided by WR or FR LEDs, respectively), WR130 + FR50, WR100 + FR30, and WR80 + FR50]. Lettuce that was grown only under natural light (NL) conditions was considered the control. According to the results of the present study, supplementary light increased biomass accumulation, and the contents of ascorbic acid, total soluble sugar, and starch relative to the control. Lettuce plants treated with WR130 + FR50 treatment presented the highest shoot and root fresh/dry weights, the highest total chlorophyll content, and the best nutritional quality, whereas the lettuce weight did not differ between the WR130 + FR30 and WR100 + FR30 treatments. Compared with that of NL, the stacking of thylakoids increased most intensely in response to the WR130 + FR50 and WR100 + FR30 treatments. Biomass accumulation, nutritional quality, stomatal area, chloroplast area, and expression of photosynthesis-related genes (LHCb, PsbA, rbcL, and rbcS) in lettuce plants, as well as light use efficiency, presented increasing-to-decreasing trends as the FR fraction increased. In conclusion, partially substituting PAR with FR photons coincidentally aligns with the supplementation of FR photons, and a supplementary FR fraction of 0.50 to 0.56 is suitable for greenhouse-grown lettuce under weak light conditions because of the increased photochemical efficiency, biomass accumulation, and carbohydrate content.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12870-025-06205-6.
... PFALs have advantages such as high resource utilization, higher annual yield per unit area, superior crop quality, year-round production capabilities, and lower site selection requirements [1]. Despite their high efficiency and productivity, PFALs still encounter issues such as substantial investment costs, elevated operational expenses, considerable energy consumption, and less-than-ideal economic returns, with labor costs constituting 25% to 30% [2]. The automation of PFALs is inherently reliant on the synergy between mechanization and digitalization. ...
... PLSR was employed to construct a fresh weight estimation model for lettuce, with the training and testing set performances depicted in Figure 14. Utilizing this method to build a 2D metric-based fresh weight estimation model, the training set achieved an R 2 ...
Crop monitoring can promptly reflect the growth status of crops. However, conventional methods of growth monitoring, although simple and direct, have limitations such as destructive sampling, reliance on human experience, and slow detection speed. This study estimated the fresh weight of lettuce (Lactuca sativa L.) in a plant factory with artificial light based on three-dimensional (3D) reconstruction technology. Data from different growth stages of lettuce were collected as the training dataset, while data from different plant forms of lettuce were used as the validation dataset. The partial least squares regression (PLSR) method was utilized for modeling, and K-fold cross-validation was performed to evaluate the model. The testing dataset of this model achieved a coefficient of determination (R²) of 0.9693, with root mean square error (RMSE) and mean absolute error (MAE) values of 3.3599 and 2.5232, respectively. Based on the performance of the validation set, an adaptation was made to develop a fresh weight estimation model for lettuce under far-red light conditions. To simplify the estimation model, reduce estimation costs, enhance estimation efficiency, and improve the lettuce growth monitoring method in plant factories, the plant height and canopy width data of lettuce were extracted to estimate the fresh weight of lettuce in addition. The testing dataset of the new model achieved an R² value of 0.8970, with RMSE and MAE values of 3.1206 and 2.4576.
... The most promising spectra shared the same red-to-blue wavelengths ratio, but W-RB 3 differs by including a white fraction. Among the wavelengths in the PAR spectrum, although red photons display the lowest intrinsic energy content, they also represent the most energetically efficient wavebands in pushing photosynthesis activities, due to their emission efficacy (Kozai and Niu, 2016;Kozai et al., 2020). Blue radiation with high energy is absorbed and moved to lower-energy chromophores in the photosynthetic reaction centre, with any remaining energy being lost as heat. ...
... White light, which covers the entire PAR region, also includes green wavebands within the spectrum. Green light has greater penetrability compared to blue and red light, with transmissivity by green leaves which is about 30%, while blue and red light transmissivity is about 0% (Kozai and Zhang, 2016;Kozai et al., 2020). As a result, green light promotes biomass accumulation in the lower regions of the canopy and deeper parts of leaves, supporting the assimilation of carbon through photosynthesis (Smith et al., 2017;Kusuma et al., 2020). ...
... Furthermore, the control that the farmer can exercise in such production units is incomparable to traditional forms of cultivation [3]. Plant factories can provide a clean, healthy, and superior-quality food source for millions of people around the world [4]. Vegetables and fruits grow with no pesticides, herbicides and other parasites, since the production is soilless, and most importantly, beyond seasonal limitations [5]. ...
Within this field of research, a wind resource evaluation can identify the locations where wind-induced heat losses can have a greater impact on the overall losses of plant factories, as well as those locations where it may not be as significant. This study focuses on choosing the optimal locations for plant factories based on wind resource assessment in Davleia, Central Greece. Based on the results, suitable regions for plant factory/vertical farms locations were suggested. The study analyses the heat losses due to wind in two scenarios with various wall surfaces based on annual wind speed, direction, and temperature experimental data from a mast. The heat transfer in a wall surface with 10 m ² and an annual average wind speed of 4.6 m/s, can be more than 18 MWh/yr. The investigation showed that while places outside the built-up agglomerations can face noticeably larger heat losses, there are sites within Davleia with low wind speeds that can limit heat loss. The study offers useful information for choosing suitable locations based on an analysis of the wind resource.
... In single pass hydroponic systems, in addition to the benefits of supply management, recollection and recycling of irrigation water or fertigation water can result in significant savings. Reuse of water is an excellent option for advanced controlledenvironment agriculture (CEA) systems (Kozai et al., 2015). Recycling of nutrient solutions used in CEA would reduce the amount of nutrients that enter freshwater bodies like ponds, lakes, rivers etc. ...
Lettuce grown under recycled hydroponics ensures efficient water and nutrient utilization. However, lettuce yield is often reported to be declined from successive cultures for accumulating phytotoxic root exudates. Degrading toxic exudates by titanium-based electrode and increasing photosynthetic efficiency by adding green light would improve lettuce yield. Alternate current electro-degradation (AC-ED) was applied along with addition of green light in light spectrum to enhance lettuce yield. Lettuce seedlings were grown in plant factory using half-strength of Enshi solution. Three consecutive cultures were performed under three combinations of LEDs [Red (R):Green (G): Blue (B) viz. 235:00:59, 211:30:53 and 187:60:47 μmol m-2 s-1] using renewed (RW), non-renewed (NR) and AC-ED applied non-renewed (NR+AC-ED) nutrient solutions. Results showed that in subsequent cultures, lettuce yield declined in NR solution under 187:60:47 of R:G:B. Contrarily, NR+AC-ED solutions showed maximum lettuce growth and enhanced about 30% of yield under 30 μmol m-2 s-1 of green light addition. However, addition of 60 μmol m-2 s-1 of green light showed lower yield under all nutrient solutions. Nutritional quality of lettuce was not varied by nutrient solutions and LEDs. Our study recommends applying AC-ED for reutilizing fertigation water and addition of 30 μmol m-² s-1 green light for higher lettuce yield under successive cultivation.
... Compared to conventional farming, vertical farming systems use up to 95% less water by growing crops in controlled indoor conditions using hydroponics and aeroponics . According to Kozai et al. (2019), modern greenhouses optimize energy and resource consumption by employing AI-based temperature controls and LED illumination. ...
Agriculture faces unprecedented challenges, including resource scarcity, climate change, and the need to feed a growing global population. This study explores the role of technological innovations and sustainable practices in overcoming these challenges and ensuring long-term food security. By employing a mixed-methods approach, the research highlights the transformative potential of innovations such as precision agriculture, IoT, AI, and biotechnology, alongside sustainable practices like regenerative agriculture, agroforestry, and crop diversification. Key findings indicate that precision technologies improve resource efficiency and yields, while sustainable methods enhance soil health and mitigate environmental impacts. However, barriers such as high costs, limited technological access, and knowledge gaps hinder widespread adoption, particularly among smallholder farmers in developing regions.The study underscores the importance of public-private partnerships, capacity-building initiatives, and policy interventions to bridge these gaps. Targeted subsidies, incentives for adopting sustainable practices, and infrastructure development are recommended to promote equitable access to agricultural advancements. Future research directions include the development of affordable, scalable technologies tailored for smallholder farms, and exploring the integration of traditional knowledge with modern innovations to create context-specific solutions. By addressing these challenges and leveraging opportunities, this research contributes to advancing a sustainable and resilient agricultural sector capable of ensuring global food security.
... Automated controllers adjust CO 2 concentration, air temperature, relative air humidity, and light, following software-based growing protocols, and fans ensure airflow (SharathKumar et al. 2020). Such systems require virtually no pesticides and potentially eliminate nutrient loss to the natural environment (Kozai et al. 2020;van Delden et al. 2021). The high energy consumption for LEDs and air conditioning systems is a major challenge to economic viability. ...
With the possibility of co‐optimizing all growth factors in vertical farming, such systems could contribute to future food supply, but the potential productivity is unknown. Analyzing 171 publications with 1403 data points across 10 crop categories from controlled‐environment experiments revealed major productivity variation among and within crop species. Potato produced the most edible dry mass of 33 g m⁻² day⁻¹, 28 times more per layer than open‐field cultivation. High planting density crops generally showed a high productivity, while crops with longer life cycles were less productive considering time and space. The limits of productivity, defined as the points at which optimizing growth factors return no further benefit, remain uncertain. Uncovering this limit requires systematic, standardized, and scalable controlled‐environment experiments across crop types.
... Controlled environment agriculture (CEA) empowers managing plant growth and development through advanced horticultural techniques and technological innovations. Indoor production offers numerous benefits, including improved crop performance and solutions to global issues like freshwater shortages, limited arable land, and extreme weather [1,2]. The rise of technologies has led to the emergence of smart farming, which allows for more efficient resource allocation and automation [3]. ...
Controlled environment agriculture (CEA) facilitates the management of plant growth and development through innovative horticultural technologies. Specific features of obligatory halophytes require diverse cultivation conditions compared to leafy vegetables grown in CEA. An ice plant was grown in walk-in chambers, and the impact of the following aspects was evaluated: (I) photosynthetically active photon flux density (PPFD) of 150, 200, 250, 300 µmol m⁻² s⁻¹; (II) spectral composition of red (R), blue (B), RB, and RBFR (far-red); (III) 12 h, 16 h, and 24 h photoperiod; (IV) hydroponic solution pH at 5.0–5.5, 5.5–6.0, and 6.0–6.5; and (V) hydroponic solution salinity concentrations at 0, 50, 100, 150, and 200 mM L⁻¹ NaCl. Other cultivation parameters were maintained constant. The results demonstrate that the ice plant was not sensitive to lighting duration at a constant daily light quantity. However, to enhance the phytochemical and mineral content per biomass, it is suggested that 250 µmol m⁻² s⁻¹ be used. While growth remains unaffected, pH levels 6.0–6.5 lead to an increased accumulation of fructose, citric, malic, and fumaric acids. In contrast, pH levels of 5.0–5.5 enhance the accumulation of mineral elements. Nutrient solution salinity of 50 mM NaCl is potentially optimum for ice plant growth. Further research is needed to evaluate the complex effect of environmental conditions for halophytes cultivation in CEA.
... This significantly enhances production quality while supporting the development of localized food supply chains. Studies have shown that vertical farming can achieve yields over 1000 times greater than those of traditional open-field farming [137]. In cities like New York, Tokyo, and Paris, vertical farms are increasingly used not only to provide fresh, local food but also to improve urban air quality and mitigate heat through green infrastructure [45,72]. ...
Metropolitan areas increasingly confront complex challenges related to food security, social inequality, environmental degradation, and resource scarcity, exacerbated by rapid urbanization, climate change, and the reliance on extended, fragile supply chains. Urban and peri-urban agriculture (UPA) is recognized as a promising approach to mitigate these issues. For example, it enhances food security and nutrition by strengthening local food supply systems, improves livelihoods by providing employment and income for local residents, and promotes environmental sustainability through the creation of greening spaces and reduction of food miles. However, the full potential of UPA remains constrained by various technological, economic, and social barriers, such as limited growing spaces, lack of land tenure security, low economic efficiency, and insufficient public awareness and acceptance. Given that the technological innovations are critical in overcoming these barriers and maximizing the positive impacts of UPA, this review provides a state-of-the-art overview of advanced technologies and tools applicable to UPA, aiming to inform how these innovations can be better enabled to enhance UPA’s contributions to sustainable urban food systems. The review begins by defining UPA, categorizing its various forms, and exploring its multifunctional roles within urban contexts. It then presents a thorough analysis of a range of UPA technologies that serve specific purposes, including productivity and product quality improvement, space utilization optimization, resource recycling, and land use management. Furthermore, the review evaluates the current challenges faced by these technologies throughout the stages of research and development (R&D), dissemination and extension, and application and commercialization, employing an analytical framework adapted from Technology Life Cycle theories. In conclusion, the review emphasizes the crucial roles that UPA and relevant technological innovations play in transforming food systems and urban environments. It proposes four key recommendations: (1) enhancing funding mechanisms and fostering interdisciplinary collaboration for UPA R&D, (2) strengthening UPA technology dissemination systems, (3) promoting economic feasibility and market integration within UPA business models, and (4) establishing supportive environments among all stakeholders in the innovation process. These targeted strategies are essential for scaling UPA technologies, thereby strengthening food security, environmental sustainability, and socio-economic resilience in metropolitan areas.
... By precisely adjusting the combination of light and water, we can more systematically explore the effects of different light-water conditions on the growth and quality of P. notoginsen [16]. With the advancement of agricultural modernization, the plant factory, as a modern and efficient agricultural system [17], has a high-precision and intelligently controlled production system which can overcome the restrictions of the natural environment by adjusting environmental factors such as LED lights and water [18,19], and achieve sustainable and efficient, high-quality, healthy, and green production of annual crop production [20][21][22]. In recent years, it has been found that LED artificial light can promote the root growth of Perilla frutescens crops, along with the chlorophyll fluorescence, which were significantly affected by light qualities. ...
Panax notoginseng (Burkill) F. H. Chen, as a traditional Chinese medicinal herb with significant therapeutic effects, is highly sensitive to environmental factors during its growth process, particularly light and water conditions. Under traditional field conditions, natural limitations make it difficult to achieve optimal yield and quality. This study aimed in the past to determine the optimal light–water interaction model for the year-round cultivation of P. notoginseng in a controlled plant factory environment. The experiment used one-year-old, uniformly grown P. notoginsen seedlings. At the beginning of the experiment, the light source, without any shading treatment, provided a photosynthetically active radiation (PAR) intensity of 200 μmol·m⁻²·s⁻¹, measured at a distance of 30 cm from the plant canopy. A total of 18 treatment combinations were established, specifically two different light quality treatments (A Treatment with a red-to-blue light ratio of 4:1 and B Treatment with a red-to-blue light ratio of 5:1) were each combined with three irrigation levels (field water capacities of 40%, 50%, and 60%) and three shading levels (one layer of 60% shading net, two layers of 60% shading net, and three layers of 60% shading net). Each light quality treatment was combined with all three irrigation levels and all three shading levels, resulting in 18 distinct treatment combinations. The effects of different light–water interactions on P. notoginseng growth were evaluated by measuring key agronomic traits, chlorophyll fluorescence parameters, and ginsenoside content. The results indicate that light–water interactions significantly affect the agronomic traits, chlorophyll fluorescence parameters, and ginsenoside content of P. notoginseng (light treatment had a more significant impact on the growth of P. notoginsen than water treatment). The best performance in terms of plant height (15.3 cm), stem diameter (3.45 mm), leaf length (8.6 cm), fresh weight (3.382 g), and total ginsenoside content (3.8%) was observed when the red-to-blue light ratio was 4:1 (A Treatment), the field water capacity was 50%, and the shading level was three layers. Based on this, the Pearson correlation analysis was used to identify eight highly correlated indicators, and the entropy-weighted TOPSIS model was applied to comprehensively evaluate the cultivation schemes. The evaluation results show that the optimal cultivation scheme for P. notoginseng is under the conditions of a red-to-blue light ratio of 4:1 (A Treatment), field water capacity of 50%, and three-layer shading.
... Some types of CEA-specifically PFALS-are claimed to be able to produce high-quality, pesticide-free food that requires no washing by the consumer (Kozai & Niu, 2020a). However, these advantages depend on effective pest exclusion and food safety practices. ...
... However, in vertical farming systems, the vertically arranged plant shelves cast shadows on the layers below, significantly reducing light exposure. Studies show that the bottom layer can receive as little as 50% to 10% of the light that reaches the top layer, making light a significant challenge [4] in vertical farming. ...
As the global population grows, vertical farming offers a promising solution by using vertically stacked shelves in controlled environments to grow crops efficiently within urban areas. However, the shading effects of farm structures make artificial lighting a significant cost, accounting for approximately 67% of total operational expenses. This study presents a novel approach to optimizing the deployment of laser illumination in rotating vertical farms by incorporating structural design, light modeling, and photosynthesis. By theoretically analyzing the beam pattern of laser diodes and the dynamics in the coverage area of rotating farm layers, we accurately characterize the light conditions on each vertical layer. Based on these insights, we introduce a new criterion, cumulative coverage, which accounts for both light intensity and coverage area. Then, an optimization framework is formulated, and a swarm intelligence algorithm, Differential Evolution (DE) is used to solve the optimization while considering the structural and operational constraints. It is found that tilting lights and placing them slightly off-center are more effective than traditional vertically aligned and center-aligned deployment. Our results show that the proposed strategy improves light coverage by 4% compared to the intensity-only optimization approach, and by 10% compared to empirical methods. This study establishes the first theoretical framework for designing energy-efficient artificial lighting deployment strategies, providing insights into enhancing the efficiency of vertical farming systems.
... In Japan, the Mirai Plant Factory has become a global leader in vertical farming, using advanced LED lighting and climate control technologies to produce high-quality crops year-round. This project has been particularly successful in addressing food supply challenges in disaster-prone regions, demonstrating the resilience and adaptability of vertical farming systems (Kozai et al., 2015;Mirai Plant Factory, 2024). These international projects highlight the potential of vertical farming to address global food security challenges through innovative, sustainable practices. ...
... INTRODUCTION Plant factories are highly controlled cultivation systems that operate throughout the year. In Japan, plant factories provide an effective solution for crop production, which is normally subjected to changing climatic conditions (Goto, 2011;Kozai et al., 2016;Takatsuji, 2010). Furthermore, innovation in incidental light-emitting diode light sources has improved plant cultivation. ...
The efficient production of useful substances in plant factories is very attractive to secure the nutrition for human health in the future. The aim of this study was to investigate the growth behavior of rice sprouts to establish a high‐density production system for plant factories. To clarify the material balance during the growth of sprout of brown rice, a single individual of rice was cultivated in vitro. The weight of the sample and the oxygen and carbon dioxide concentrations in the test tube were measured, with bioactivity indices being calculated. The contribution of growth respiration was confirmed based on the growth, oxygen uptake, and carbon dioxide evolution rates. The specific growth rates and oxygen concentrations all increased during the 60‐ to 80‐h period. The decrease in the specific oxygen uptake rate and carbon dioxide evaluation rate generally corresponded to the 90‐ to 160‐h period. These results suggest that the physiological state of rice sprouts can be evaluated using bioactivity indices obtained from individual cultivation systems. A trial application for the high‐density heterotrophic cultivation of rice sprouts was performed using the developed container. The growth productivity of rice sprouts cultivated in containers was similar to that of individual test tubes. These results showed the new value of crop cultivation by the plant factory.
... The construction and operation of plant factories often require substantial capital investment, which is frequently a primary cause of operational failure (Kozai et al., 2019). These significant investments are mainly allocated to four equipment systems: a. Advanced environmental control systems b. ...
... Low-pressure aeroponic systems use less powerful pumps and nozzles to create a coarser mist of nutrient solution [28]. While less efficient than high-pressure systems, lowpressure aeroponics still provides the benefits of soilless cultivation and reduced water consumption. ...
... In addition to greenhouse production, indoor vertical farming under LED lighting is gaining popularity as a more efficient and attractive method of crop production. These systems are known by various acronyms, including VFS (vertical farming systems) (Van Delden et al. 2021), PFAL (plant factory using artificial lights) (Kozai et al. 2019), LVS (LEDequipped vertical systems) (Moosavi-Nezhad et al. 2022b), and CPPS (closed plant production systems) (Kozai 2013). ...
Light is an essential source of energy for photosynthesis, which regulates plant growth and morphology. Although vertical farms are vastly practiced for crop production, their potentials for flower production are recently recognized owing to its efficient use of area in a season-independent way. This study examined the effects of light quality and phytohormones application on growth, morphology, and photosynthesis of African violet (Saintpaulia ionantha L.) leaf cuttings. Therefore, gibberellic acid (GA3), zeatin (ZEA), and water (control) were applied on plants that were exposed to red (R), red-blue (R:B), and red-blue-far-red (R:B:F) lights. Results showed highest growth (above-ground biomass fresh and dry weight, root fresh weight, plant fresh and dry weight, number of leaves, and plant leaf area) were recorded in GA3-treated plants that were exposed to RB and RBF lights. Adding FR light caused petiole elongation, which may not be commercially valuable. The highest inflorescence achieved under RBF light, while the lowest inflorescence occurred under R light, furthermore GA3 negatively affected inflorescence. Chlorophyll fluorescence analysis revealed that monochromatic R light reduced photosynthetic capacity, while multichromatic RB and RBF lights and phytohormone application enhanced photosynthetic functionality. Phytohormones under multichromatic lights increased leaf pigmentations. Compact plants with high flowering was achieved in ZEA-treated plants that were exposed to RB light, which adds to their marketable value. In conclusion, multichromatic RB and RBF light spectra combined with ZEA and GA3 application improved growth, photosynthetic capacity, and pigment contents in African violet, making it an ideal choice for indoor farming.
... On a global scale, indoor vertical farms are emerging as an innovative approach for strawberry production (Kosai et al. 2019) with a variety of environmental and economic benefits (Park et al. 2023), including ...
Indoor vertical farms can optimize light, temperature, humidity, and nutrient use, thus potentially maximizing crop growth and yield. However, the reported potential for enhanced crop growth and yield within these systems needs to be tempered against the understanding of the effects of this “forced growth”/optimal growth environment on “actual” plant performance to fully reap the benefits of these innovative vertical farming systems. We investigated the effect of calcium (Ca) on the production of strawberries in an indoor vertical farm system with varying photosynthetic photon flux density (PPFD). Fruit yield of plants fed with high Ca (9 meq·L ⁻¹ ) increased by 42.3% when the PPFD was 422 µmol·m ⁻² ·s ⁻¹ ; however, a subsequent increase to 572 µmol·m ⁻² ·s ⁻¹ resulted in a decline in fruit production. Plants treated with low Ca (5 meq·L ⁻¹ ) had a reduced yield and demonstrated no response to the PPFD. The observed increase in yield was associated with increased fruit production and total soluble solids. Plants exhibited 21.5% and 57.8% increases in the total dry weight when exposed to 422 and 572 µmol·m ⁻² ·s ⁻¹ , respectively; however, Ca did not have any impact on this response. Independent of the Ca concentration, the photosynthesis rate increased by 16.1% and 22.2% when the PPFD increased to 422 and 572 µmol·m ⁻² ·s ⁻¹ , respectively; however, the highest photosynthesis rate was recorded with 422 µmol·m ⁻² ·s ⁻¹ when the Ca level was 9 meq·L ⁻¹ . High Ca-fed plants exhibited a reduction in Ca (−17.1%) content in their fruits when exposed to 572 µmol·m ⁻² ·s ⁻¹ , which was likely caused by a dilution effect attributable to increased fruit biomass. In contrast, shoot Ca increased when plants were given high Ca when the PPFDs were 422 and 572 µmol·m ⁻² ·s ⁻¹ . The Ca concentration in shoots correlated with the increasing yield, and a higher Ca concentration was associated with the increasing transpiration rate and stomatic conductance. Shoot phosphorus declined when plants were exposed to increased PPFD, and phosphorus was lower when plants were provided with 9 meq·L ⁻¹ of Ca; however, plants watered with low Ca solutions had more potassium. The shoot nitrogen content and micronutrient contents were unchanged regardless of the variations in PPFD or Ca. In summary, the favorable conditions for the cultivation of strawberry under controlled environments resulted in greater growth and fruit yield as long as Ca was provided at higher concentrations in the irrigation solutions (from 5 to 9 meq·L ⁻¹ ). We suggest that the higher demand of Ca that is necessary to satisfy the enhanced plant development observed in indoor farming systems may be connected to the role of Ca in the formation of new tissues, cell walls, and cell membranes.
... For example, many cultivars cultivated outdoors were selected for their frost hardiness, pest resistance, and ease of transport 51 . Nevertheless, many cultivars that were selected for outdoor farms are currently being grown in indoor farms 52 . It is reasonable to expect that indoor farms near urban centers can enhance the cultivation of fruits and vegetables with superior culinary qualities. ...
A novel, optimized, polysaccharide and biochar-based, compostable hydrogel horticultural growing substrate for use in hydroponics and vertical farming was created based upon empirical methods and statistical design of experiments. A 15-run D-optimal mixture design of experiments was completed that increased the 14-day plant growing ability of a five-component hydrogel nearly ten-fold from 4.3695 g to 41.2623 g per 100 plants. The data were analyzed using a standard least squares method with an effect screening emphasis, and a model was created that maximized the signal to noise ratio. There was a good correlation between the measured and predicted values of the model, with an r-squared value of 0.90. The predictions of efficacy and compostability were confirmed with subsequent experiments that showed the hydrogel was composted in less than 84 days and that the plant growth predicted by the model differed from the experimental growth by 0.65%. The resulting optimized formulation had a high fertilizer content for a growth medium. We therefore suggest that an empirical approach to formulation research can produce superior outcomes with a statistically designed study.
... However, since the production and cultivation system in a vertical farm require human intervention, their operating costs could be higher than those of open-field and greenhouse farming. Besides the cost of land, which is dominated by geographical advantages, the most important cost relates to energy in its various forms, e.g., temperature, humidity, lighting, gas supply, etc. that is required to regulate and monitor the environment for plant cultivation [2][3][4]. As a result, it has been established that the cost of vertical farming is high, which plays against sustainability core objectives. ...
The rise of high-rise vertical farms in cities is helping to mitigate urban constraints on crop production, including land, transportation, and yield requirements. However, separate issues arise regarding energy consumption. The utilisation of wind energy resources in high-rise vertical farms is therefore on the agenda. In this study, we investigate the aerodynamic performance of an ellipsoidal tall building with large openings to determine, on the one hand, the threshold income wind that could impact human comfort, and on the other, the turbulence intensity at specific locations on the roof and façade where micro-wind turbines could operate. To this end, we calculate the wind pressure coefficient and turbulence intensity of two scale models tested within a wind tunnel facility and compare the results with a separate CFD simulation completed in the past. The results confirm that the wind turbines installed on the building façade at a height of at least z/h = 0.725 can operate properly when the inlet wind speed is greater than 7 m/s. Meanwhile, the wind regime on the roof is more stable, which could yield higher energy harvesting via wind turbines. Furthermore, we observe that the overall aerodynamic performance of the models tested best under wind flowing at angles of 45° and 60° with respect to their centreline, whereas the turbulence at the wind envelope compares to that of the free wind flow at roof height.
... When LEDs are used as the sole source of lighting for crop production, energy expenditure accounts for at least 30% of the total operational cost (Kong et al. 2019;Kozai 2013;Kozai and Niu 2020). During its seedling stage, a lettuce crop has a small leaf area relative to the production area it occupies, and incident photons are not intercepted and used efficiently. ...
Although far-red (FR) radiation (700–750 nm) is beyond the traditional photosynthetically active radiation (PAR) waveband (400–700 nm), recent findings suggest equivalent or similar photosynthetic action when applied along with shorter PAR wavelengths. Potential interactive effects of FR with other environmental factors that affect photosynthesis, such as CO 2 , have not been widely established. In the present study, the effects of four FR photon flux densities (0, 20, 40, or 60 µmol·m ⁻² ·s ⁻¹ ) substituting for red (R; 600–700 nm) in combination with three CO 2 concentrations (400, 800, or 1200 µmol·mol ⁻¹ ) were investigated at three distinctive stages of young red lettuce production. We tested whether the photomorphogenic response of young plant leaves to FR would result in a higher light interception area, as well as whether interactive effects of CO 2 with FR might modify the effects of FR alone. The total photon flux density (TPFD) was maintained at a low limiting intensity of 200 µmol·m ⁻² ·s ⁻¹ (daily light integral: 11.5 mol·m ⁻² ·d ⁻¹ ), consistent with indoor commercial setpoints for sole-source lighting. Although blue (B; 400–500 nm) was held constant at 20 µmol·m ⁻² ·s ⁻¹ for all treatments, different combinations of R and FR were adjusted. Red oakleaf lettuce ( Lactuca sativa ‘Rouxai’) used as a model test crop was harvested at 14 days (small baby greens), 18 days (standard baby greens), and 22 days (teen greens) after sowing. Crop productivity was highest at 800 µmol·mol ⁻¹ CO 2 for small and standard baby stages. At the teen green stage, plant productivity was similar for the two elevated CO 2 concentrations. The FR substitution for R did not affect dry biomass accumulation at all CO 2 concentrations tested, thus supporting equivalent photosynthetic action. A photomorphogenic effect of FR that elongated but did not increase the area of leaves persisted from the earliest to the most mature stage of crop development tested. The FR inclusion in the light recipe resulted in longer, thinner leaves with lower biomass compared to those without FR. At higher FR fluxes, purple pigmentation reduction occurred. However, the interaction of elevated CO 2 with FR radiation counteracted purple pigment reduction caused by FR alone. Substitution of FR in the light recipe for indoor production of young ‘Rouxai’ lettuce at low limiting light intensity did not improve productivity, even in combination with elevated CO 2 .
... Dynamic feedback control based on a crop's developmental stage can enhance the resource use efficiency of crop production systems. In particular, the productivity of indoor farming is highly dependent on the efficiency of environmental controls [5]; in this case, the dynamic control can significantly reduce input costs [6]. Dynamic data collection should precede feedback control to obtain appropriate feedback. ...
Crop growth information is collected through destructive investigation, which inevitably causes discontinuity of the target. Real-time monitoring and estimation of the same target crops can lead to dynamic feedback control, considering immediate crop growth. Images are high-dimensional data containing crop growth and developmental stages and image collection is non-destructive. We propose a non-destructive growth prediction method that uses low-cost RGB images and computer vision. In this study, two methodologies were selected and verified: an image-to-growth model with crop images and a growth simulation model with estimated crop growth. The best models for each case were the vision transformer (ViT) and one-dimensional convolutional neural network (1D ConvNet). For shoot fresh weight, shoot dry weight, and leaf area of lettuce, ViT showed R2 values of 0.89, 0.93, and 0.78, respectively, whereas 1D ConvNet showed 0.96, 0.94, and 0.95, respectively. These accuracies indicated that RGB images and deep neural networks can non-destructively interpret the interaction between crops and the environment. Ultimately, growers can enhance resource use efficiency by adapting real-time monitoring and prediction to feedback environmental controls to yield high-quality crops.
... With the advancement of protected agriculture and vertical farming technologies, there has been a growing interest in utilizing these systems to produce high-quality crops under precisely controlled conditions [30]. Vertical farms, in particular, provide an ideal environment for applying biotechnological approaches like elicitation, allowing for the efficient regulation of plant growth and the optimization of secondary metabolite production, including valuable cannabinoids in C. sativa [31,32]. ...
Cannabis sativa, a versatile plant containing over 150 cannabinoids, is increasingly valued for its medicinal properties. It is classified into hemp and marijuana based on its Δ9-tetrahydrocannabinol (Δ9-THC) content. The objective of this study was to optimize cannabinoid production in hemp within a vertical farming system by investigating the effects of methyl jasmonate (MeJA) on plant growth and specific cannabinoid contents. After propagating hemp plants, they were treated with various concentrations of MeJA (0, 100, 200, and 400 μM). Plant growth parameters, glandular trichome (GT) density, and the contents of specific cannabinoids—cannabidiolic acid (CBDA), cannabidiol (CBD), tetrahydrocannabinolic acid (THCA), and Δ9-THC—were analyzed. The results showed that MeJA treatment decreased plant height and leaf area while increasing GT density and the synthesis of CBDA and THCA at lower concentrations. Specifically, treatment with 100 μM MeJA provided optimal conditions for enhancing cannabinoid production while controlling plant height, which is advantageous for vertical farming. These findings suggest that precise application of MeJA in controlled environments can increase yields of valuable cannabinoids with efficient use of space, thereby enhancing the commercial and medicinal value of hemp.
... Hence, there is a need to develop rapid, innovative, and well-organized cultivation methods to ensure consistent ginseng production. In contrast to conventional farms and greenhouses, vertical farming offer the advantage of maintaining precise control over environmental cultivation conditions, unaffected by fluctuations in the external environment (Kozai et al. 2019). Furthermore, vertical farming enables the potential for year-round planning of production, allowing the realization of substantial annual yields of high-quality crops. ...
Panax ginseng C.A. Meyer, a valuable medicinal plant with abundant antioxidants has been used for centuries due to its potential health benefits including boosting of immune system, cognitive function, sexual function and reducing stress. The popularity of ginseng sprouts (GS) is driven by their convenience and ease of use as a ginseng consumption option, particularly when compared to mature ginseng roots. Employing controlled environmental conditions, including the adjustment of artificial lighting and air temperature, presents an appealing approach for cultivating GS of high quality within a condensed timeframe. In this study, we investigated the impact of four distinct day–night temperature difference (DIF) regimes, viz., − 4 DIF (18/22 °C), 0 DIF (20/20 °C), 0 DIF (22/22 °C), and + 4 DIF (22/18 °C), on the morpho-physiology, antioxidant activity, and the accumulation of minerals and ginsenosides in GS. To promote growth parameters, both positive and zero DIF conditions (22/22 °C) were beneficial, however the positive DIF condition played a significant role in enhancing chlorophyll a levels, photosynthetic efficiency, and enzymatic antioxidant activities. Although negative DIF was conducive for mineral accumulation, it had adverse effects on growth, antioxidant activities, and ginsenoside production. The zero DIF, particularly (22/22 °C) has boosted the non-enzymatic antioxidant activities and mineral uptake, while (20/20 °C) has facilitated the ginsenoside synthesis. The significant upregulation of ginsenoside biosynthesis genes further validated the accumulation of ginsenosides under zero DIF conditions. Hence, the present study elucidates the advantageous implications of diverse DIF conditions, offering a potential avenue for enhancing ginseng cultivation in the vertical farming system.
Marjoram (Origanum majorana L.) is a highly valued herb known for its aromatic and medicinal properties. There has been growing interest in developing improved marjoram varieties through innovative breeding strategies in recent years. This chapter provides an overview of the recent advancements in marjoram breeding techniques and explores the potential for enhancing various desirable traits in this herb. The chapter discusses the importance of Marjoram as a versatile herb with numerous applications in the culinary, pharmaceutical, and cosmetic industries. It highlights the need for innovative breeding approaches to overcome challenges such as low yields, disease susceptibility, and limited genetic diversity. Next, the chapter explores conventional breeding methods, including selection, hybridization, backcrossing, and their applicability in marjoram improvement. It delves into identifying and evaluating desirable traits such as yield, essential oil content and composition, disease resistance, and adaptability to different environmental conditions. Genetic mapping and molecular markers in marjoram breeding initiatives are also examined. Genomic and transcriptomic data are used to uncover trait-related genes and expedite breeding with marker-assisted and genomic selection. Genome editing, gene stacking, and genomic prediction could manipulate Marjoram’s phenotype and improve genetics quickly. This chapter concludes with marjoram breeding’s future and the need for eco-friendly methods. It promotes safeguarding marjoram germplasm, studying wild relatives for distinctive traits, and breeding with genomic and molecular approaches. This chapter summarises marjoram breeding strategy developments, helping researchers, breeders, and stakeholders increase cultivation, quality, and production.
An innovative agricultural technique termed vertical farming utilizes controlled environment and stacked growth systems to maximize food production. Vertical farming ensures year-round vegetable cultivation while maximizing space, conserving water, and minimizing pesticide use, in contrast to conventional farming, which needs a lot of land and is affected by weather. In metropolitan locations where land is limited and food security grows into a greater concern, this method is extremely advantageous. In the production of vegetables, vertical farming's primary objectives are to increase output per unit area, reduce dependence on natural resources, enable for continuous cultivation, and enhance the nutritional value of vegetables. Vegetable farming has been transformed by a number of methods, including hydroponics, aeroponics, and aquaponics, which do not require soil and produce precise nutrient delivery. The c rop yield is further increased by Controlled Environment Agriculture (CEA), which maintains ideal CO₂, humidity, and temperature levels.In vertical farming, lighting plays an important role as it has a direct effect on plant yield and growth. When available, natural light is utilized, but solar panels and LED systems provide the spectrum required for photosynthesis. LEDs provide customizable wavelengths for the best plant growth, while semi- transparent solar cells maintain a
compromise between energy production and light penetration. The capacity of vertical farming to increase yields while maintaining nutritional quality is supported by research on leafy greens like spinach and lettuce. As technology continues to develop, vertical farming presents a scalable and sustainable approach to the problems of environmental degradation and food security. Its versatility makes it a viable substitute for traditional farming, guaranteeing year-round access to fresh, locally grown, pesticide-free vegetables.
In a plant factory, maintaining proper and uniform air/moisture movement above the crop canopy is crucial for aiding plant growth. This research has utilized a three-dimensional computation model to investigate airflow and heat transfer in a plant factory, where airflow, heat, and humidity distributions above plant crops were calculated concerning five categories of crop planting density (Pd) and air change rate (ACH) in the crop area. Spatial uniformities of airflow velocity, temperature, and relative humidity immediately above the crops are evaluated using the objective uniformity parameter (OU), relative standard deviation of temperature (RSDT) and relative standard deviation of relative humidity (RSDRH), respectively. Furthermore, a factor of effectiveness (θ) is defined, depending on the uniformity of velocity, temperature, and relative humidity distribution, to comprehensively evaluate the impact of various ACH with Pd on overall effectiveness. Full numerical results show that air velocity, temperature, and relative humidity above the crops are notably influenced by Pd and ACH. As ACH increases, the OU of the air above the indoor crop also expands. Moreover, higher OU values are observed for smaller crop Pd. However, excessively small crop area planting densities and excessively large ACH do not result in a higher OU for the air above the crop. As ACH increases, both RSDT and RSDRH decay for the whole range of crop Pd. Moreover, smaller Pd values could achieve the uniformity of thermal fields, while having minimal effects on the relative humidity distributions. Generally, increasing ACH and decreasing Pd could enhance overall value of θ. However, excessively increasing ACH and decreasing Pd does not have a significant effect on θ, which is jointly influenced by OU, RSDT, and RSDRH. Therefore, a more suitable combination of ACH and Pd is urgently required to improve the design of agricultural system to enhance crop microclimate uniformity for optimal plant growth and productivity.
This study presents a solar-sharing smart illumination technology powered by renewable energy sources and driven by Artificial Intelligence for enhancing the growth of high-valued crops, particularly lettuce, in indoor hydroponics systems. Through the use of renewable energy sources and Arduino technology, this research also strives to help achieve the Sustainable Development Goals (SDGs) of the UN regarding food security by optimizing plant growth. The system's design focuses on energy efficiency and sustainability, aligning with SDGs such as Zero Hunger, Climate Action, and Life on Land. By integrating Arduino, renewable energy sources, and artificial intelligence, the system automatically adjusts LED illumination levels to optimize crop growth. Through the implementation of AI models, the system enhances plant growth performance at different developmental stages. The control system controls when the LEDs turn on as well as the intensity in response to the on and off states intensity of sunlight. The lettuce's performance throughout growing increased subsequent the effective implementation of the system. Through innovative lighting control and smart technologies, this study demonstrates a sustainable approach to indoor farming that supports global efforts towards achieving a more food-secure and environmentally conscious future.
The chapter “Working Method of Aeroponics: The article “Innovations in Soilless Agriculture” explains how aeroponic farming works, and the parts of an aeroponic system, with particular concentration on particular farming procedures. Aeroponics provides an organic technique to address contemporary horticulture's problems by delivering suspended plant roots in air with nutrient enriched mist. Its advantages include better nutrient uptake, good aeration and very reduced water and other resource use as compared to conventional soil-based farming. Each of them is elaborated on in the chapter and described its influence on the growth of plants in the given aeroponic system; these components include the growth chamber, the system of misting the leaves, nutrient supplying, and the environmental factors regulating the plant growth.
Aeroponics, a soilless cultivation technique, is gaining momentum as a transformative solution in modern agriculture. This chapter explores its commercial applications, focusing on its ability to revolutionize traditional farming and support sustainable food production. By delivering nutrients directly to plant roots in a controlled environment, aeroponics offers benefits like faster growth rates, higher yields, and reduced resource use. The chapter examines its adoption in urban farming, vertical farming, and greenhouse operations, along with its economic viability and environmental impact. Through case studies, the potential of aeroponics to shape the future of agriculture is highlighted, offering a practical overview of its commercial prospects.
The use of extended light spectra, including UV-A, green, and far-red, has been scarcely explored in vertical farming. This study evaluated the effects of full spectra under two intensities (90 and 180 µmol m⁻² s⁻¹) on the growth and antioxidant properties of green and purple leaf lettuce. Three light spectra were tested: Blue-White (BW), Red-White (RW), and Red-Blue (RB). Fresh weight (FW), dry weight percentage (DWP), chlorophyll concentration (NDVI), and antioxidant parameters (total phenolic content (TPC), antioxidant capacity by DPPH and FRAP and total flavonoid content (TFC)) were assessed. Spectrum-intensity interactions significantly influenced FW, with RW-180 µmol m⁻² s⁻¹ yielding the highest FW (78.2 g plant⁻¹ in green and 48.5 g plant⁻¹ in purple lettuce). BW-90 µmol m⁻² s⁻¹ maximized DWP in green lettuce, while PAR intensity of 180 µmol m⁻² s⁻¹ favored DWP in purple lettuce. Chlorophyll concentration increased under PAR intensity of 180 µmol m⁻² s⁻¹, and leaf color varied with spectrum, with RW producing lighter leaves. Antioxidant parameters declined over time, but a PAR intensity of 180 µmol m⁻² s⁻¹, particularly under RW, boosted TPC and TFC contents in both lettuce cultivars during early stages (days 0 and 15). Conversely, a lower PAR intensity of 90 µmol m⁻² s⁻¹, mainly under RW, enhanced antioxidant capacity by FRAP at 15 days and by the end of the cycle for both cultivars. Overall, RW-180 µmol m⁻² s⁻¹ interactions promoted the best characteristics in lettuce. Nonetheless, the findings emphasize the significance of fine-tuning both light spectrum and intensity to enhance lettuce growth and quality in vertical farming systems considering the cultivar, time and variable to be evaluated.
Urbanization is rapidly transforming global cities. As cities grow, they face complex challenges, including food security, environmental degradation, and the need for sustainable urban growth models. This thesis explores the innovative concept of “Vertical Urban Oases,” which combines vertical farming with superblock urban design to address these challenges. By integrating food production, housing, commercial spaces, and public services within a compact, self-sustaining urban framework, the vertical urban oasis model offers a potential solution for creating livable, resource-efficient cities. The research focuses on hot, arid areas like New Aswan City, Egypt, as a case study to evaluate this model's feasibility, sustainability, and socio-economic impacts.
This research is highly significant due to its focus on addressing two interlinked global challenges: food security and sustainable urbanism. It contributes to global efforts to combat urban sprawl and resource depletion, providing a practical framework for cities experiencing rapid urbanization. The study highlights vertical farming as a cornerstone for creating self-sustaining urban ecosystems, particularly in regions like Egypt, where per capita arable land has declined by 79% over the past century.
Existing studies emphasize individual aspects of urban sustainability, such as green roofs, vertical agriculture, or compact urbanism. However, there is a notable gap in research exploring the integration of vertical farming with superblock urban designs to create holistic, self-sustaining urban ecosystems. This thesis bridges this gap by proposing and evaluating a Vertical Urban Oasis model, focusing on its technical, economic, and social feasibility in the context of Egypt’s arid urban environments.
Rapid urbanization, expected to reach 70% of the global population by 2050, poses critical challenges, especially in regions like Egypt, where arable land per capita has declined by 79% over the past century. This growth exacerbates food insecurity, environmental degradation, and urban sprawl, straining limited resources and threatening sustainable urban development. Traditional agricultural practices cannot meet the demands of dense urban populations, requiring innovative solutions. This research addresses these challenges by proposing the concept of “Vertical Urban Oases,” integrating vertical farming with superblock urban design to promote food security, environmental sustainability, and efficient land use in rapidly growing cities.
The research aims to assess the technical, environmental, economic, and social viability of integrating vertical farming within superblock designs as a model for sustainable urbanism. The specific objectives are, Evaluate Vertical Farming Feasibility: Assess crop productivity, resource efficiency, and economic viability of vertical farming systems such as hydroponics, aquaponics, and aeroponics. Integrate Vertical Farming and Superblocks: Investigate how this integration enhances urban compaction, livability, and sustainability in dense urban settings. Analyze Socio-Technical Challenges: Identify cultural, technical, and policy barriers to implementing the Vertical Urban Oasis model. Develop Guidelines and Policies: Propose actionable recommendations to support the adoption of vertical farming and urban compaction strategies.
The research adopts a mixed-methods approach to assess the vertical urban oasis's technical, economic, and social viability. Quantitative data is collected on crop yields, resource efficiency, and cost-effectiveness, while qualitative data from stakeholder interviews and focus groups provides insights into the perceived benefits, challenges, and cultural factors influencing the model's acceptance. Key stakeholders include urban planners, architects, government officials, and residents, whose feedback was crucial in shaping the recommendations for the model's implementation.
Results and Outcomes
The findings highlight the transformative potential of the Vertical Urban Oasis model, which offers significant benefits across multiple dimensions:
1. Urban Compaction: The model minimizes urban sprawl, optimizes land use, and preserves ecosystems.
2. Sustainable Food Production: Advanced vertical farming technologies enable year-round cultivation, reducing water and land requirements.
3. Environmental Impact: The model reduces carbon emissions, enhances biodiversity, and lessens the ecological footprint of urban food systems.
4. Economic Development: It generates employment, reduces food transportation costs, and optimizes resource management, contributing to local economies.
5. Social Livability: Integrated green spaces and food systems enhance community well-being and promote sustainable urban living.
Challenges
The research identifies key barriers, including:
• High Initial Costs: Infrastructure development for vertical farming requires significant financial investment.
• Technical Expertise: The model demands specialized knowledge for installation, maintenance, and operation.
• Social Resistance: Public scepticism toward new urban forms and living arrangements poses adoption challenges.
Recommendations
To overcome these challenges, the research proposes:
1. Policy Incentives: Provide financial subsidies and incentives to support vertical farming infrastructure.
2. Regulatory Frameworks: Develop clear guidelines to integrate vertical farming into urban planning systems.
3. Public-Private Partnerships: Foster collaborations between stakeholders to promote innovation and ensure financial viability.
4. Community Engagement: Actively involve residents in the planning and operation of urban farms to enhance social acceptance and adaptability.
Ultimately, this thesis contributes to the growing academic discourse on urban sustainability by offering a visionary yet practical solution for cities facing the twin challenges of urban sprawl and food security. By rigorously evaluating the vertical urban oasis model in the context of New Aswan City, this research provides valuable insights for urban planners, architects, and policymakers seeking to design more resilient and self-sustaining cities for the future. The model's potential to transform how cities approach urban agriculture and sustainability marks a significant step forward in addressing the global challenges of population growth, climate change, and resource scarcity.
Keywords: vertical urban oasis, vertical farming, superblock, sustainability, livability, urban agriculture, vertical farming, green cities
Plant factories (PFs), also known as vertical farms, are advanced agricultural production systems that operate independently of geographical and environmental conditions. They utilize artificial light and controlled environments to produce horticultural plants year-round. This approach offers a promising solution for the stable and efficient supply of high-quality horticultural produce in urban areas, enhancing resilient urban food systems. This review explores the economic and environmental impacts and potential of PFs. Breakthroughs in PF research and development are highlighted, including increased product yields and quality, reduced energy input and CO2 emissions through optimized growing conditions and automation systems, transitioning to clean energy, improved resource use efficiency, and reduced food transport distances. Moreover, innovations and applications of PFs have been proposed to address challenges from both economic and environmental perspectives. The proposed development of PF technologies for economic and environmental benefits represents a comprehensive and promising approach to urban horticulture, significantly enhancing the impact and benefits of fundamental research and industrial applications.
This comparative study investigated the effects of various aeration treatments on lettuce cultivation in a plant factory using artificial light (PFAL). A deep-water culture (DWC) hydroponic system was used in the present study. Three aeration treatments, namely macrobubbles (MA), microbubbles (MI), and ultrafine bubbles (UFB), were compared. We examined the influence of different aeration methods and fertilizer doses on lettuce growth and measured electricity consumption. The results showed that MI and UFB treatments significantly increased the yield and accelerated lettuce growth in PFAL. Relative to the MA treatment, the UFB treatment increase the SFW of lettuce by 1.5 times bigger in PFAL. Despite the increased energy consumption, UFB treatment demonstrated high energy efficiency compared to MA treatment. Notably, lettuce treated with UFB and 25% less fertilizer grew as well as lettuce given the full fertilizer dose without UFB. These findings suggest that UFB application has significant potential in PFAL. UFB enhances yield and accelerates lettuce growth.
The growth of different lettuce varieties in response to the application of ultrafine bubbles (UFB) was investigated inside a plant factory with artificial light (PFAL). Six different types of lettuce (greenwave, frilly, green leaf, butterhead, romaine, and lamb lettuce) were cultivated under UFB and control treatments using a deep flow technique (DFT) hydroponic system. As a result, the effect of UFB treatment was found to vary depending on the type of lettuce cultivar. UFB treatment was found to promote growth in greenwave, frilly, and romaine lettuce but not in green leaf, butterhead, or lamb lettuce. Compared to the control treatment, the temperature of the nutrient solution and the dissolved oxygen (DO) concentration were higher by 1.61℃ and 59.5% in the UFB treatment, respectively. These findings suggest that an increased temperature and a high DO content during UFB generation are factors that enhance lettuce growth. Taken together, these results indicate that the application of UFB in the DFT hydroponic culture system can significantly promote lettuce growth in PFAL.
Light spectrum and intensity is one of the key factors in the production of microgreens in controlled-environment agriculture and is directly related to plant growth and biomass accumulation. Hence, the objective of this research study was to investigate the biomass, growth, and resource use efficiencies (RUEs) in 14 different species of microgreen grown in two light recipes with 209.5 (OSRAM LED) and 45 µmol m⁻² s⁻¹ (INSTAGREEN LED) with a 16/8 h light/dark photoperiod in a growth chamber. Under both LEDs, fresh biomass accumulation and the SPAD content were highest in sunflower. Nasturtium recorded the maximum hypocotyl length under both LEDs. The leaf area index (LAI) was significantly higher in mungbean under the INSTAGREEN LED compared to other microgreens, while the maximum LAI was measured in lentils under the OSRAM LED. This shows that the two different LEDs had species-specific effects. The RUE of the cheaper INSTAGREEN LED was more efficient in terms of light and energy use efficiency, while OSRAM LED was more efficient in terms of water and surface use efficiencies. Overall, the results showed that different species of microgreens exhibit different responses to fresh biomass accumulation and SPAD contents in the leaves, demonstrating the diversity of their growth responses. Across both LEDs (OSRAM LED and INSTAGREEN LED), the top performing microgreen in terms of biomass accumulation as well as SPAD contents in the leaves was sunflower. Consequently, a high chlorophyll content in sunflower led to a higher biomass production by enhancing photosynthesis.
Hydroponics, the practice of growing plants without soil using mineral nutrient solutions in water, represents a significant shift in agricultural methodologies. Modern hydroponic systems have evolved substantially since the early 20th century, with advancements in system design, automation, nutrient management, and environmental control enhancing efficiency, scalability, and applicability. This review examines recent innovations that have addressed traditional challenges and created new opportunities for hydroponic cultivation. Hydroponics offers advantages over traditional soil-based agriculture, including precise nutrient control, reduced water usage, and the elimination of soil-borne diseases and pests. These benefits are critical in addressing modern agricultural challenges such as soil degradation, water scarcity, and the need for increased food production for a growing global population. Hydroponic systems can be implemented in diverse environments, making them adaptable solutions for enhancing food security and sustainability. Key developments in various hydroponic systems are highlighted, including the Nutrient Film Technique (NFT), Deep Water Culture (DWC), Ebb and Flow, Aeroponics, Wick Systems, and Drip Systems. Innovations in these systems focus on optimizing nutrient delivery, oxygenation, and integrating sensors for precise control, improving overall performance and yield. Technological advancements, such as automation and control systems, sensors, and monitoring technologies, have revolutionized hydroponic farming by enabling real-time data collection and environmental management. The integration of the Internet of Things (IoT) and smart farming practices, combined with data analytics and machine learning, has further optimized system performance and decision-making. LED lighting and vertical farming techniques have maximized space utilization and improved crop yields, particularly in urban environments. Advances in nutrient solutions, disease management, and water quality have optimized plant health and resource efficiency. Economic and environmental considerations, including cost-benefit analyses and comparisons with traditional agriculture, highlight the potential for hydroponics to offer better returns on investment and reduce environmental impact. Despite the significant progress, challenges such as high initial setup costs and technical complexities remain. Future research opportunities and interdisciplinary collaborations are essential to address these challenges and drive further innovation in hydroponic farming.
This review paper of literature highlights role of Light Emitting Diode (LED) on the growth of plants under controlled conditions of greenhouse farming particularly hydroponics. "Internet of Things (IOT)" is a system of interconnected computing devices, sensors, objects, microcontrollers, and cloud servers that can transmit data across a network and control other devices remotely without human intervention. Light Emitting Diode (LED) is a more efficient, versatile, lasts longer, highly energy-efficient, directional, narrow light spectrum, low power consumption, and little heat production. Common LED colors include amber, red, green, and blue. Hydroponic grow lights are designed to mimic the natural light that plants need for photosynthesis. Plants can only use the spectrum of visible light to produce photosynthesis, and this narrow spectrum (400 to 700 nanometer) is recognized as the Photosynthetically Active Radiation (PAR). The development and growth of diverse plant species can be influenced differently by a variety of colored LED lights. LED illumination provides an efficient way to improve yield and modify plant properties. Therefore, LED systems plays an important role in controlling morphological, genetic, physiological, chemical properties, increasing the synthesis of a variety of beneficial secondary metabolites, and optobiological interactions of plants in greenhouse farming. In general, red and blue light is essential for maximizing the photosynthesis process due to their strong absorption by the plant chlorophyll molecules. LED illumination sources are increasingly being utilized to enhance the growth rate of vegetables and herbs cultivated in greenhouses worldwide. LED illumination spectrum manipulation could enable significant morphological adaptations, and identification of the wavelength ranges is required to increase the plant photosynthesis process.
Global food security is under significant threat from climate change, population growth, and resource scarcity. This review examines how advanced AI-driven forecasting models, including machine learning (ML), deep learning (DL), and time-series forecasting models like SARIMA/ARIMA, are transforming regional agricultural practices and food supply chains. Through the integration of Internet of Things (IoT), remote sensing, and blockchain technologies, these models facilitate the real-time monitoring of crop growth, resource allocation, and market dynamics, enhancing decision making and sustainability. The study adopts a mixed-methods approach, including systematic literature analysis and regional case studies. Highlights include AI-driven yield forecasting in European hydroponic systems and resource optimization in southeast Asian aquaponics, showcasing localized efficiency gains. Furthermore, AI applications in food processing, such as plasma, ozone and Pulsed Electric Field (PEF) treatments, are shown to improve food preservation and reduce spoilage. Key challenges—such as data quality, model scalability, and prediction accuracy—are discussed, particularly in the context of data-poor environments, limiting broader model applicability. The paper concludes by outlining future directions, emphasizing context-specific AI implementations, the need for public–private collaboration, and policy interventions to enhance scalability and adoption in food security contexts.
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