Growing the Future: Exploring Vertical Farming from a Plant Science Perspective : a pilot study in hydroponic controlled environment agriculture using Ocimum basilicum, Lactuca sativa var. romana, and Lactuca sativa L.

By introducing high-density crop production in controlled environments, vertical farming (VF) offers a sustainable solution to problems with urban food security. Incorporating plant science is necessary to improve an already functioning VF system after technological improvements and breakthroughs like robotics. This is where the following pilot study steps in: examining the output of the hydroponic vertical farming system at SweGreen AB, Stockholm, where we planted basil (Ocimum basilicum), romaine lettuce (Lactuca sativa var. romana), and oakleaf lettuce (Lactuca sativa L.). One objective is to compare plant performance, post-transplant recovery support, and growth forecast across ebb and flow (EF) and the nutrient film technique (NFT) irrigation system. Further, image analysis and chlorophyll contents were used to see whether digital images can be used as a substitute for direct measurements of chlorophyll. Leaf temperature was monitored as a proxy for plant growth that is fueled by photosynthesis. NFT was found to outperform EF for the lettuce species for plant performance and prediction accuracy. Image analysis algorithms for leaf color in RGB color channels were shown to need improvement, e.g. by machine learning, to make robust statements on the correlation to chlorophyll. For leaf temperature, it was found that in NFT leaf temperature has less influence on plant growth but additional studies are needed to fully understand the mechanisms behind it. With this study, I intend to contribute to the autonomy and sustainability of vertical farms to supply people with nutritious, fresh food in the future

Characterization of plant water flows in Controlled environment -PLANT SMART SENSORS

The present thesis project "Characterization of water flows in Controlled Environment -PLANT SMART SENSORS" has a multidisciplinary core and aimed towards the creation of synergies between the world of scientific research and the industry. By applying research results to technological development, this research targeted at innovation in the Agrotechnology and Aerospace sectors. Indeed, the introduction of new technologies is pivotal for controlled environment production on Earth to feed a growing population as well as for human permanence in Space in longterm missions where plants are used to regenerate resources (e.g. oxygen, water) and as source of fresh high-nutritious food. The realization of these systems must be based on a precise knowledge of plant morpho-anatomical development and its physiological behavior in closed growth systems, which are strongly influenced by numerous environmental factors including the relative humidity or more specifically the Vapour Pressure Deficit (VPD). In a protected environment (e.g. in Space greenhouses, vertical farm, indoor growing-modules), the control of relative humidity represents a significant problem, which has often been neglected. For instance, in conditions of poor aeration, too high humidity can occur with consequent low values of VPD which reduces the plant transpiration, slowing or stopping the water flow through the SPAC (Soil-plant-atmosphere-continuum), and ultimately blocking the photosynthesis, yield and biomass production. Even though there have been many studies regarding the VPD control, alone and/or in combination with other environmental factors, certain points are still unclear or controversial, providing contrasting results in different or even in the same species. This happens mainly due to the complex interactions between many microclimatic factors and plant physiological behaviour at different phenological stages. In a context of climate change, the efficient regulation of VPD can be applied to greenhouse and indoor-module production in order to enhance crop productivity, improve WUE and reduce total water consumption to design irrigation strategies, considering the balance between the amount of water saved and the quantity used to regulate the VPD. The regulation of the VPD and related environmental parameters need to be designed according to the species and its adaptive plasticity at morphophysiological levels.  Thus, the characterization and modeling of water flows in model plants in different growth chamber scenarios (from small modules intended for the spatialization for Space applications, up to structures that can be used in protected cultivation on Earth), as well as the real-time monitoring of the water status of plants, become fundamental for the management of precision agriculture both in support of Space exploration and for the sustainability of urban agriculture. To date, most of the research has focused on either specific physiological/structural aspect at the single-plant level, or on cultivation management or even on technological aspects, with only a few interlinks of knowledge. The aim of this thesis is to develop knowledge to help filling this gap to improve the understanding of VPD effects on crop productivity, with the creation of synergies among different expertise (e.g., plant physiology, crop science, engineering). To do so, it is fundamental to study the complexity of plant morpho/physiological responses, since without a deep knowledge of mechanisms behind plant responses to the environment it is difficult to determine how and to which extent plants can adapt to any changes in the environmental conditions. The application of a multidisciplinary approach in research will allow crop production in a sustainable way, even in harsh environments, where a "climate smart-agriculture" becomes necessary to improve crop yield and quality. The present thesis is organized as follows: Chapter 1 is a review which presents the current state of knowledge on how VPD influences plant morpho-physiological traits in controlled environment agriculture. The study has been published as a review article in Annals of Applied Biology (Amitrano et al., 2019 https://doi.org/10.1111/aab.12544). It covers main important aspects of VPD influence on plant growth, morpho-anatomical development, and physiology, emphasizing the possible interaction between VPD and other microclimatic factors in protected cultivation. Furthermore, the rewiew identifies and discusses future research areas, which should be explored further, based on needed synergies among different expertise from biological and horticultural fields. Chapter 2 presents evidence that the modulation of relative humidity (RH) together with other important cultivation factors such as light (presence/absence), can influence morpho-anatomical development and improve antioxidant content, even at the early stages of plant life cycle (germination, seedling establishment). The combined effect of RH and light was studied during the germination and seedling development of Vigna radiata L. (mung bean), a species widespread throughout the world also due to the high nutritional value of its edible sprouts. A manuscript reporting these data has been published in Plants (Amitrano et al., 2020a https://doi.org/10.3390/plants9091093). In Chapter 3, the role of leaf anatomical traits (e.g. leaf mesophyll features, stomata and vein traits) in photosynthetic acclimation to short- and long-term changes in VPD was examined in Vigna radiata L. adult plants. In this study, we underlined the key role of leaf structure in photosynthetic acclimation to air VPD. The long-term exposure to different VPD levels determined a pre-acclimation at the leaf morpho-anatomical level which influenced the extent of leaf physiological plasticity, changing plant ability to acclimate to any changes in the surrounding microclimate. This different leaf anatomy-related capacity of pre-acclimating becomes therefore fundamental in the present climate-change scenario due to its key role in the adaptation process under changing environmental conditions. A manuscript reporting these data has been published in Environmental and Experimental Botany (Amitrano et al., 2021a https://doi.org/10.1016/j.envexpbot.2021.104453). In Chapter 4, the effect of VPD on morpho-physiological traits also incorporating the trade-off between transpiration and carbon gain was evaluated in two cultivars of Salanova lettuce (Lactuca sativa L.) with green and red leaves, in a growth-chamber experiment. Low-VPD turned out to significantly improve growth, stomata development and hydraulic-related traits which led to higher photosynthesis and a reduced water consumption compared to the high-VPD condition. A manuscript reporting these data was published in Agronomy (Amitrano et al., 2021b https://doi.org/10.3390/agronomy11071396).  Chapter 5 represents a clear interlink of knowledge between plant scientists, engineers, mathematician and modelists. In this study, published in Sensors (Amitrano et al., 2020b https://doi.org/10.3390/s20113110), we used experimental data, based on morpho-anatomical analyses of lettuce plants, to run the Energy Cascade Model (MEC), a model already used to predict biomass production and photosynthetic efficiency in advanced life support systems studies (Space-oriented research). Here, the modification of the model is discussed together with possible improvements and applications. Chapter 6 focuses on how to modulate the micro-environment, and in particular the VPD levels, in protected cultivation to improve plant antioxidant content in crops. More specifically, the exposure of the same lettuce cultivars mentioned in previous chapters to high VPD determined an improved phytochemical content in lettuce leaves, especially in the red cultivar. Here we discussed a further possibility to use short-term high VPD treatments as a mild stress to boost the phytochemical production in lettuce plants. A Manuscript reporting these data has been published in Horticulturae (Amitrano et al., 2021c http://doi.org/10.3390/horticulturae7020032). Chapter 7 is a deep focus on how the VPD drives the coordination among morpho-anatomical traits in leaves of the above-mentioned lettuce cultivars, also exploring the variability of traits along the leaf lamina. More specifically, the attention is focused on how stomata and vein develop within lettuce leaves and how these traits are coordinated with leaf size under different VPDs. Results from this study suggest that VPD triggers a different response in lettuce plants in terms of balance of leaf 4 traits and highlight the possibility of further exploring the microenvironment (combined influence of light and VPD) to adjust the development of stomata and vein densities, thus providing optimal water and gas fluxes through the leaves. In Chapter 8, the experiments conducted during the period spent at the Controlled Environment Agriculture Center of the University of Arizona (UA-CEAC) are reported. The experiments reported here were conducted on the same species of the previous chapters (Salanvoa lettuce with green and red leaves) in a multi-layer vertical farm to test the interaction between VPD and other microclimatic factors on plant morpho-physiological development. More specifically two experimental trials are reported (E1 and E2). In E1, the interaction between VPD levels (low and high) and increasing DLI (Daily Light Integral - 8.6, 12.9, 15.5) was tested to study morpho-physiological changes and to determine the optimal combination of DLI and VPD for lettuce growth. In E2, a sudden salt stress was applied to the cultivation and then CO2 enrichment was provided, based on the hypothesis that the CO2 enrichment would mitigate the salt stress, modifying the plant carbon gain/water balance. We evaluated whether the mechanisms of salt stress mitigation due to CO2 enrichment were different under high and low VPD conditions, depending on the different morphoanatomical leaf structure.   Chapter 9 reports on experiments conducted at the IPK-Leibniz institute of plant genetics and crop plant research (Gatersleeben, Germany) in the framework of the EPPN2020 transnational access (https://eppn2020.plant-phenotyping.eu/EPPN_Transnational_Access). A report with obtained results is showed in this chapter. These experiments concern the application of high-throughput phenotyping combined with morpho-anatomical analyses on Salanova green and red plants acclimated to a VPD level and then subjected to short-term changes in the VPD. The project submitted to the EPPN transnational access and winner of the grant is presented in Appendix 1. Chapter 10 and 11 report on the possible industrial applications after the collaboration with the partner company "Kayser Italia srl" (http://www.kayser.it/). Chapter 10 is a study for the definition of scientific and technical requirements for the realization of a miniaturized phenotyping growth chamber to grow microgreens or small crops in Space. The structure of the chamber is based on the "Kubik" incubator, an incubator facility of the European Space Agency with the shape of a cube of about 40 cm that has been operating aboard the International Space Station for more than 12 years, carrying different life science experiments. In the chapter, technical and scientific requirements are listed and a preliminary schedule for the project realization is provided. At the end of the chapter, open issues are also discussed. In Chapter 11, the set-up of a prototype miniaturized cultivation chamber for use in Space is described and the results of validation tests, carried out at Kayser Italia with brassica microgreens (Brassica rapa subsp. sylvestris var. esculenta) under different air relative humidities (VPD), are reported. In Appendix 1, the project submitted to the EPPN transnational access (PHEW- Automated phenotyping platform to improve lettuce water use efficiency under different VPD and watering regimens) and winner of the grant is presented. In Appendix 2, a brief recap on the activities conducted during the Ph.D. program is presented

Automation and Control

Advances in automation and control today cover many areas of technology where human input is minimized. This book discusses numerous types and applications of automation and control. Chapters address topics such as building information modeling (BIM)–based automated code compliance checking (ACCC), control algorithms useful for military operations and video games, rescue competitions using unmanned aerial-ground robots, and stochastic control systems

Integrated Environmental Modelling Framework for Cumulative Effects Assessment

Global warming and population growth have resulted in an increase in the intensity of natural and anthropogenic stressors. Investigating the complex nature of environmental problems requires the integration of different environmental processes across major components of the environment, including water, climate, ecology, air, and land. Cumulative effects assessment (CEA) not only includes analyzing and modeling environmental changes, but also supports planning alternatives that promote environmental monitoring and management. Disjointed and narrowly focused environmental management approaches have proved dissatisfactory. The adoption of integrated modelling approaches has sparked interests in the development of frameworks which may be used to investigate the processes of individual environmental component and the ways they interact with each other. Integrated modelling systems and frameworks are often the only way to take into account the important environmental processes and interactions, relevant spatial and temporal scales, and feedback mechanisms of complex systems for CEA. This book examines the ways in which interactions and relationships between environmental components are understood, paying special attention to climate, land, water quantity and quality, and both anthropogenic and natural stressors. It reviews modelling approaches for each component and reviews existing integrated modelling systems for CEA. Finally, it proposes an integrated modelling framework and provides perspectives on future research avenues for cumulative effects assessment

Guiding the development of a controlled ecological life support system

The workshop is reported which was held to establish guidelines for future development of ecological support systems, and to develop a group of researchers who understand the interdisciplinary requirements of the overall program

Controlled Ecological Life Support System: Research and Development Guidelines

Results of a workshop designed to provide a base for initiating a program of research and development of controlled ecological life support systems (CELSS) are summarized. Included are an evaluation of a ground based manned demonstration as a milestone in CELSS development, and a discussion of development requirements for a successful ground based CELSS demonstration. Research recommendations are presented concerning the following topics: nutrition and food processing, food production, waste processing, systems engineering and modelling, and ecology-systems safety

Management and Modeling of Winter-time Basil Cultivars Grown with a Cap MAT System

Basil (Ocimum basilicum) is a high value crop, currently grown in the field and greenhouses in Nebraska. Winter-time, greenhouse studies were conducted during 2015 and 2016, focusing on cultivars of basil grown on a Cap MAT II® system with various levels of fertilizer application. The goal was to select high value cultivars that could be grown in Nebraska greenhouses. The studies used water content, electrical conductivity, photosynthetically active radiation (PAR), and relative humidity, air and soil media temperature sensors. Greenhouse systems can be very complex, even though controlled by mechanical heating and cooling. Uncertain or ambiguous environmental and plant growth factors can occur, where growers need to plan, adapt, and react appropriately. Plant harvest weights and electronic sensor data was recorded over time and used for training and internally validating fuzzy logic inference and classification models. Studies showed that GENFIS2 ‘subtractive clustering’ of data, prior to ANFIS training, resulted in good correlations for predicted growth (R2 \u3e 0.85), with small numbers of effective rules and membership functions. Cross-validation and internal validation studies also showed good correlations (R2 \u3e 0.85). Decisions on basil cultivar selection and forecasting as to how quickly a basil crop will reach marketable size will help growers to know when to harvest, for optimal yield and predictable quantity of essential oils. If one can predict reliably how much essential oil will be produced, then the methods and resultant products can be proposed for USP or FDA approval. Currently, most plant medicinal and herbal oils and other supplements vary too widely in composition for approval. The use of fuzzy set theory could be a useful mathematical tool for plant and horticultural production studies