Indoor Farm Research Articles

Can LED Lighting Be a Sustainable Solution for Producing Nutritionally Valuable Microgreens?

With its quality, intensity, and photoperiod, light is a decisive abiotic factor that directly influences plant biomass and the accumulation of specialized metabolites (SMs). Photosynthetically active radiation (PAR) has significant effects on primary and secondary plant metabolism and thus influences the morphological characteristics of plants and their antioxidant systems. The aim of this study was to investigate the effects of blue, red, and a 50:50 combination of blue and red LED lighting on the SM content in broccoli, mustard, and garden cress microgreens grown in an indoor farm using the zero-acreage farming technique (ZFarming). This research aims to provide valuable insights into the optimization of light spectra to improve the nutritional quality of microgreens, with a focus on sustainable and space-saving cultivation methods. After eight days, the samples were cut in the cotyledon phenophase and analyzed in a fresh state. The microgreens grown under the blue spectrum LED lighting had the highest content of ascorbic acid (112.70 mg·100 g fw−1), total phenolics (412.39 mg GAE·100 g fw−1), and the highest antioxidant capacity (2443.62 µmol TE·L−1). The results show that the highest content of SMs in all the studied microgreens species was accumulated under the blue spectrum LED lighting. This study underlines the favorable influence of the blue spectrum (400–500 nm) on the nutrient content, especially the enhancement of SMs, in the microgreens investigated. Furthermore, the use of supplemental LED lighting proves to be a sustainable and effective means of producing microgreens with superior nutritional properties through the innovative practice of the zero-acreage farming technique.

Production planning in an indoor farm: Using time and space requirements to define an efficient production schedule and farm size

Abstract Indoor agriculture is an innovative and environmentally sustainable approach to high-quality food production, utilizing advanced technology to reduce water usage by 95% and achieve a 100-fold increase in production per unit of land compared to conventional farming systems. These enclosed systems provide year-round production of pesticide-free fresh food, even in cities with less favourable climates, addressing food deserts and creating employment opportunities in urban areas. However, the industry faces significant challenges, primarily stemming from substantial investment and operating costs, exacerbated by a limited understanding of the input-output relationship within these systems. This study employs a bioeconomic framework to establish a foundational production function based on growth cycle duration (time) and required growing area (space). Through a partial budget analysis, a 19-day production schedule was identified to provide the highest contribution margin to profits. Results set the minimum size of this hypothetical lettuce indoor farm at 273 m2, rendering it suitable for installation in urban areas. The farm harvests 118 kg per day, within an 800 m2 growing area distributed across four vertically stacked shelves. Estimates of economic output sensitivity to exogenous factors in the US context are also presented, along with a comparison between cost-minimizing and revenue-maximizing strategies.

Minimizing Escherichia coli O157:H7 contamination in indoor farming: effects of cultivar type and ultra-violet light quality.

Bacterial contamination of produce is a concern in indoor farming due to close plant spacing, recycling irrigation, warm temperatures, and high relative humidity during production. Cultivars that inherently resist contamination and photo-sanitization using ultraviolet (UV) radiation during the production phase can reduce bacterial contamination. However, there is limited information to support their use in indoor farming. Lettuce (Lactuca sativa) cultivars with varying plant architectures grown in a custom-built indoor farm exhibited differences in E. coli O157:H7 survival after inoculation. The survival of E. coli O157:H7 was lowest in the leaf cultivar (open architecture) and highest in the romaine and oakleaf cultivars (compact architecture). Of the different UV wavelengths that were tested (UV-A, UV-A + B, UV-A + C), UV A + C at an intensity of 54.5 μmol m-2 s-1 (with 3.5 μmol m-2 s-1 of UV-C), provided for 15 min every day, was found to be most efficacious in reducing the E. coli O157:H7 survival on romaine lettuce with no negative effects on plant growth and quality. Contamination of E. coli O157:H7 on lettuce plants can be reduced and the food safety levels in indoor farms can be increased by selecting cultivars with an open leaf architecture coupled with photo-sanitization using low and frequent exposure to UV A + C radiation. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Optimization of Plant Nutrition in Aquaponics: The Impact of Trichoderma harzianum and Bacillus mojavensis on Lettuce and Basil Yield and Mineral Status.

The present study aims to test the effect of a nutrient solution, with the addition of microbial inoculum, on the growth and mineral composition of 'Hilbert' and 'Barlach' lettuce cultivars (Lactuca sativa var. crispa, L.) and basil (Ocimum basilicum, L.) cultivated in a vertical indoor farm. These crops were grown in four different variants of nutrient solution: (1) hydroponic; (2) aquaponic, derived from a recirculating aquaculture system (RAS) with rainbow trout; (3) aquaponic, treated with Trichoderma harzianum; (4) aquaponic, treated with Bacillus mojavensis. The benefits of T. harzianum inoculation were most evident in basil, where a significantly higher number of leaves (by 44.9%), a higher nitrate content (by 36.4%), and increased vitamin C (by 126.0%) were found when compared to the aquaponic variant. Inoculation with T. harzianum can be recommended for growing basil in N-limited conditions. B. mojavensis caused a higher degree of removal of Na+ and Cl- from the nutrient solution (243.1% and 254.4% higher, in comparison to the aquaponic solution). This is desirable in aquaponics as these ions may accumulate in the system solution. B. mojavensis further increased the number of leaves in all crops (by 44.9-82.9%) and the content of vitamin C in basil and 'Hilbert' lettuce (by 168.3 and 45.0%) compared to the aquaponic solution. The inoculums of both microbial species used did not significantly affect the crop yield or the activity of the biofilter. The nutrient levels in RAS-based nutrient solutions are mostly suboptimal or in a form that is unavailable to the plants; thus, their utilization must be maximized. These findings can help to reduce the required level of supplemental mineral fertilizers in aquaponics.

Production Planning in an Indoor Farm: Using Time and Space Requirements to Define an Efficient Production Schedule and Farm Size

Production Planning in an Indoor Farm: Using Time and Space Requirements to Define an Efficient Production Schedule and Farm Size

Retracted: Performance Analysis and Development of a Semiconductor Junction Rectifier with Multicolor Coding for Indoor Farm Applications

Retracted: Performance Analysis and Development of a Semiconductor Junction Rectifier with Multicolor Coding for Indoor Farm Applications

Cow key point detection in indoor housing conditions with a deep learning model

Lameness in dairy cattle is a costly and highly prevalent problem that affects all aspects of sustainable dairy production, including animal welfare. Automation of gait assessment would allow monitoring of locomotion in which the cows' walking patterns can be evaluated frequently and with limited labor. With the right interpretation algorithms, this could result in more timely detection of locomotion problems. This in turn would facilitate timely intervention and early treatment, which is crucial to reduce the effect of abnormal behavior and pain on animal welfare. Gait features of dairy cows can potentially be derived from key points that locate crucial anatomical points on a cow's body. The aim of this study is 2-fold: (1) to demonstrate automation of the detection of dairy cows' key points in a practical indoor setting with natural occlusions from gates and races, and (2) to propose the necessary steps to postprocess these key points to make them suitable for subsequent gait feature calculations. Both the automated detection of key points as well as the postprocessing of them are crucial prerequisites for camera-based automated locomotion monitoring in a real farm environment. Side-view video footage of 34 Holstein-Friesian dairy cows, captured when exiting the milking parlor, were used for model development. From these videos, 758 samples of 2 successive frames were extracted. A previously developed deep learning model called T-LEAP was trained to detect 17 key points on cows in our indoor farm environment with natural occlusions. To this end, the dataset of 758 samples was randomly split into a train (n = 22 cows; no. of samples = 388), validation (n = 7 cows; no. of samples = 108), and test dataset (n = 15 cows; no. of samples = 262). The performance of T-LEAP to automatically assign key points in our indoor situation was assessed using the average percentage of correctly detected key points using a threshold of 0.2 of the head length (PCKh0.2). The model's performance on the test set achieved a good result with PCKh0.2: 89% on all 17 key points together. Detecting key points on the back (n = 3 key points) of the cow had the poorest performance PCKh0.2: 59%. In addition to the indoor performance of the model, a more detailed study of the detection performance was conducted to formulate postprocessing steps necessary to use these key points for gait feature calculations and subsequent automated locomotion monitoring. This detailed study included the evaluation of the detection performance in multiple directions. This study revealed that the performance of the key points on a cows' back were the poorest in the horizontal direction. Based on this more in-depth study, we recommend the implementation of the outlined postprocessing techniques to address the following issues: (1) correcting camera distortion, (2) rectifying erroneous key point detection, and (3) establishing the necessary procedures for translating hoof key points into gait features.

Testing Cultivar-specific Tipburn Sensitivity of Lettuce for Indoor Vertical Farms

Low evaporative conditions in indoor (vertical) farms reduce mass-flow–driven transport of calcium (Ca), resulting in tipburn of lettuce. Lettuce tipburn symptoms develop along the margins of young leaves and the growing shoot tip, where necrotic tissue forms as a result of Ca deficiency. For indoor farms, lettuce tipburn poses a major economic risk because the crop becomes unmarketable as a result of its appearance. Difference in tipburn sensitivity among cultivars has been thought to be related to differences in growth rate, morphology, or anthocyanin production, whereas most commercial lettuce cultivars have been known to express tipburn symptoms in the indoor farm setting. We created a tipburn-inducing growing condition in walk-in growth chambers that limits plant potential transpiration rate while achieving relatively high growth rates, and examined 10 commercial cultivars selected for tipburn sensitivity. Selected cultivars differ in morphology (butterhead, romaine, and leafy type) and color (red or green; resulting from anthocyanin production). All cultivars expressed visually detectable tipburn symptoms 22 ± 2.6 days after transplanting, and varied tipburn rates of 7% to 41% of all leaves at the time of harvest (28 days after transplanting). Despite cultivar-specific variation, neither lettuce morphology nor anthocyanin content were significantly correlated with the incidence or severity of tipburn. However, cultivars recommended for “indoor” production by seed suppliers had less tipburn severity than those recommended for outdoor or both indoor and outdoor production systems. Although tipburn risk may vary under other environmental conditions, low evaporative conditions in this experiment caused tipburn symptoms in all tested cultivars at varying degrees of severity. Cultivar-specific average yield and tipburn severity were not correlated with the Ca concentrations in the inner leaves, suggesting that the amount of tissue Ca required to prevent tipburn is cultivar specific and not related to yield. Our selected tipburn-inducing condition was found to be effective in comparing tipburn sensitivity of lettuce cultivars for indoor farm settings, and similar fast-growing but low-evaporative conditions should be used to assess cultivars for indoor farm production.

Public perception and social sustainability of indoor farming technologies: A systematic review

Indoor farming applications have recently been identified as a potential alternative to contribute to sustainable food production in the urban context. Anyhow, the social impacts of these technologies are still uncertain. The first purpose of this study is to analyse the public perception of indoor farming products and to identify the factors that influence it. The second aim is to assess the positive and negative impacts that these new technologies could have on society. A systematic review of the literature on indoor farming applications was performed to answer these research questions. Following this approach, 40 publications were selected and analysed. The results show that consumers are still uncertain about indoor food production, mainly due to the lack of naturalness. Anyhow, effectively communicating the benefits of these technologies to the public can help to increase their acceptability. Social benefits found in the literature include increased fresh food supply, social integration, revaluation of urban areas, educational opportunities, and added value in terms of the local economy and job creation. To successfully develop from a social point of view indoor farm projects must integrate different functions and carefully evaluate the context in which they are set. The main challenges will be the increase of accessibility, inclusion, and transparency of this production process, as well as gaining financial and political support. Given consumers’ uncertainty around these technologies, it seems essential for managers to increase sustainability potential while effectively conveying these benefits to the public. Further quantitative research in this field, as well as policies and regulations, will be needed for market development.

Growing biofortified microgreens in indoor farm and in greenhouse: a comparison

Growing biofortified microgreens in indoor farm and in greenhouse: a comparison

Internet of things-based indoor smart hydroponics farm monitoring system

Internet of things (IoT)-enabled systems are being used to monitor, control, and optimize agricultural systems like hydroponics. Optimization of these systems requires monitoring of various growth factors for plants which will also require multiple sensors. With the number of wireless sensors needed to track the conditions of the hydroponics system, the wireless sensor network will also grow in size and complexity. In this paper, a hybrid IoT-based monitoring system, with both wired and wireless components, with a target indoor farm application is proposed. The system was implemented using controller area network for the wired component, IPv6 over low power wireless personal area network (6LoWPAN) for the wireless component, and Amazon Web Services for the cloud services. Network simulations were performed to compare the network performance of the proposed hybrid system and the purely wireless system. The simulations show that incorporating a wired system results in improvements such as the reduction of packet loss from 12.23% in the purely wireless system to 5.62% in the hybrid system with burst traffic and even down to 0.0% in the hybrid system with continuous traffic.

Vertical farming for crop production

Vertical farming for crop production

Performance evaluation of a novel adjustable lampshade-type reflector (ALR) in indoor farming practice using choy sum (Brassica rapa var. parachinensis).

The retrieval of lost light energy for promoting vegetable development could be a challenge in indoor farming practice, yet little is attempted so far. In this study, the performance of a novel adjustable lampshade-type reflector (ALR) was investigated to evaluate the feasibility of applying such a device in indoor farm racks (IFR). This application targeted at reflecting stray light back to the IFR for improving the growth and quality of leafy vegetable choy sum (Brassica rapa var. parachinensis). The optimal configuration of ALR was firstly confirmed via simulations using TracePro software. The combination of an included angle at 32° and a reflective board width of 10 cm, under 12 cm of distance between the light sources and the germination tray surface, was revealed to achieve a cost-optimal reflective effect. The simulation-based ALR was subsequently custom-built for actual performance validation. It was shown to effectively produce uniform distributions of temperature, relative humidity, and photosynthetic photon flux density as well as to accumulate more photosynthetic photon energy density along the cultivation shelf. Compared with the control where no ALR was used, the fresh weight and the dry weight of choy sum shoots cultivated using an ALR were increased by up to 14% and 18%, respectively. In addition, their morphological traits were found to be more uniform. Furthermore, their total carotenoid level was enhanced by up to 45%, while the chlorophyll b level was markedly decreased. However, no statistically significant difference was found in total phenolic content and antioxidant capacity across the shelf, indicating that the ALR application led to a more uniform antioxidant-related quality of choy sum shoot. ALR application in IFR can thus effectively boost vegetable production and result in quality improvements under an identical amount of electricity consumption in indoor farming compared with ALR-free control.

Milk metagenomics and cheese-making properties as affected by indoor farming and summer highland grazing.

The study of the complex relationships between milk metagenomics and milk composition and cheese-making efficiency as affected by indoor farming and summer highland grazing was the aim of the present work. The experimental design considered monthly sampling (over 5 mo) of the milk produced by 12 Brown Swiss cows divided into 2 groups: the first remained on a lowland indoor farm from June to October, and the second was moved to highland pastures in July and then returned to the lowland farm in September. The resulting 60 milk samples (2 kg each) were used to analyze milk composition, milk coagulation, curd firming, and syneresis processes, and to make individual model cheeses to measure cheese yields and nutrient recoveries in the cheese. After DNA extraction and Illumina Miseq sequencing, milk microbiota amplicons were also processed by means of an open-source pipeline called Quantitative Insights Into Microbial Ecology (Qiime2, version 2018.2; https://qiime2.org). Out of a total of 44 taxa analyzed, 13 bacterial taxa were considered important for the dairy industry (lactic acid bacteria, LAB, 5 taxa; and spoilage bacteria, 4) and for human (other probiotics, 2) and animal health (pathogenic bacteria, 2). The results revealed the transhumant group of cows transferred to summer highland pastures showed an increase in almost all the LAB taxa, bifidobacteria, and propionibacteria, and a reduction in spoilage taxa. All the metagenomic changes disappeared when the transhumant cows were moved back to the permanent indoor farm. The relationships between 17 microbial traits and 30 compositional and technological milk traits were investigated through analysis of correlation and latent explanatory factor analysis. Eight latent factors were identified, explaining 75.3% of the total variance, 2 of which were mainly based on microbial traits: pro-dairy bacteria (14% of total variance, improving during summer pasturing) and pathogenic bacteria (6.0% of total variance). Some bacterial traits contributed to other compositional-technological latent factors (gelation, udder health, and caseins).

Optimizing optical fiber daylighting system for indoor agriculture applications

Optical fiber daylighting technology offers an effective path to deliver sunlight to an indoor farm that requires high energy consumption for illumination and a total visible spectrum for plant growth. However, the high cost of this technology can be seen as a drawback. In this study, the optimized daylighting system based on plastic optical fiber for indoor farm application is devised toward large-scale illumination with high efficiency and low cost. The proposed system comprises of a Fresnel lens array as a sunlight concentrator and plastic optical fiber bundles as a light transportation medium. Rather than previously common designs, we investigated the concentration properties of a non-imaging optics device – the Fresnel lens to find the optimal configuration of the system. Optimizing concentration ratio, optical efficiency, and overheating of an optical fiber daylighting system (OFDS) for the indoor farm application is carried out by simulation (LightTools software) and verified by experiments. The system design allows replacing the costly and sophisticated heat dissipation in conventional OFDS with only a UV-IR filter. The OFDS prototype is fabricated and tested in outdoor conditions. Results show that the proposed system archive concentration ratio of 140, the optical efficiency of ∼19 % by simulation, and ∼16 % by practice. Daylighting performance investigation on the installation of the prototype in the indoor farm demonstrates that energy saving can reach 54.3 % on a sunny day and 38.9 % on a cloudy day. Using proposed OFDS helps the plant to grow better than using LED only. Reliability tests and cost analyses show that our results provide an essential breakthrough for the application and commercialization of large-scale optical fiber daylighting technology for indoor agriculture.

Detection of Tip-Burn Stress on Lettuce Grown in an Indoor Environment Using Deep Learning Algorithms.

Lettuce grown in indoor farms under fully artificial light is susceptible to a physiological disorder known as tip-burn. A vital factor that controls plant growth in indoor farms is the ability to adjust the growing environment to promote faster crop growth. However, this rapid growth process exacerbates the tip-burn problem, especially for lettuce. This paper presents an automated detection of tip-burn lettuce grown indoors using a deep-learning algorithm based on a one-stage object detector. The tip-burn lettuce images were captured under various light and indoor background conditions (under white, red, and blue LEDs). After augmentation, a total of 2333 images were generated and used for training using three different one-stage detectors, namely, CenterNet, YOLOv4, and YOLOv5. In the training dataset, all the models exhibited a mean average precision (mAP) greater than 80% except for YOLOv4. The most accurate model for detecting tip-burns was YOLOv5, which had the highest mAP of 82.8%. The performance of the trained models was also evaluated on the images taken under different indoor farm light settings, including white, red, and blue LEDs. Again, YOLOv5 was significantly better than CenterNet and YOLOv4. Therefore, detecting tip-burn on lettuce grown in indoor farms under different lighting conditions can be recognized by using deep-learning algorithms with a reliable overall accuracy. Early detection of tip-burn can help growers readjust the lighting and controlled environment parameters to increase the freshness of lettuce grown in plant factories.

Current Technologies and Target Crops: A Review on Australian Protected Cropping

Protected cropping offers a way to bolster food production in the face of climate change and deliver healthy food sustainably with fewer resources. However, to make this way of farming economically viable, we need to consider the status of protected cropping in the context of available technologies and corresponding target horticultural crops. This review outlines existing opportunities and challenges that must be addressed by ongoing research and innovation in this exciting but complex field in Australia. Indoor farm facilities are broadly categorised into the following three levels of technological advancement: low-, medium- and high-tech with corresponding challenges that require innovative solutions. Furthermore, limitations on indoor plant growth and protected cropping systems (e.g., high energy costs) have restricted the use of indoor agriculture to relatively few, high value crops. Hence, we need to develop new crop cultivars suitable for indoor agriculture that may differ from those required for open field production. In addition, protected cropping requires high start-up costs, expensive skilled labour, high energy consumption, and significant pest and disease management and quality control. Overall, protected cropping offers promising solutions for food security, while reducing the carbon footprint of food production. However, for indoor cropping production to have a substantial positive impact on global food security and nutritional security, the economical production of diverse crops will be essential.

Efficiency of the electric energy consumption of an indoor farm by focusing on optimized lighting strategies

Efficiency of the electric energy consumption of an indoor farm by focusing on optimized lighting strategies

스마트팜 레스토랑의 친환경심리혜택에 관한 연구 : 행동 의도와 인구통계학적 특성을 중심으로

Smart farms are environmentally friendly and future-oriented agriculture, and also they play an important role in the restaurant industry. Therefore, this study tried to examine the importance of psychological benefits of green in the context of ‘indoor smart farm restaurants.’ More specifically, this study examined how three sub-dimensions of psychological benefits of green (i.e. warm glow, nature experiences, and self-expressive benefits) affect behavioral intentions. In addition, this study investigated the differences among the three sub-dimensions of psychological benefits of green based on the respondents’ demographic factors. For this, the study collected 320 responses, and data analysis results indicated that all of the three dimensions of psychological benefits of green significantly affect behavioral intentions. In addition, the results showed that differences in warm glow and nature experiences were partially found in gender, age, and marital status.

Bringing the outside in: Indoor farm

I made an indoor farm using natural resources with a group of children when I was teaching reception age. It was such a success, I wanted to share the idea with you.