Dissertations / Theses on the topic 'Hydroponic greenhouse'

In a world with an ever growing population, the ability to grow food eciently is essential. One way to improve the eciency is by automation. The purpose of this project is therefore to investigate how the identification of a plant’s stage in its growth cycle that can be made autonomous. This was done with the method of measuring the amount of green pixels in an image of the plant. To be able to answer our research questions a demonstrator was built. The demonstrator is a greenhouse with a non regulated aeroponic system, a regulation system for humidity and an identification system for determining the plant growth stage. The plant chosen to test the identification system was basil. The identification system successfully identified the stage of plants well into the adult stage, in the seed stage and in the middle of the sprout stage. It was however not always successful in the identification of plants transitioning from the sprout stage into the adult stage.
I en värld med en ständigt växande befolkning är förmågan att odla mat effektivt nödvändig. En metod för att öka denna effektivitet är genom automatisering. Syftet för detta projekt är därför att undersöka hur identifieringen av en plantans stadie i dess växtcykel kan automatiseras. Detta gjordes genom att mäta antalet gröna pixlar i en bild av plantan. För att kunna svara våra forskningsfrågor byggdes en testmiljö. Testmiljön bestod av ett växthus med ett oreglerat aeroponiskt system, ett regulationssystem för luftfuktighet och ett identifikationsssystem för att avgöra en plantas stadie i dess växtcykel. Plantan som valdes för att testa identifikationssystemet var basilika. Identifikationssystemet som togs fram kunde med framgång identifiera stadiet av en planta som är långt in i dess vuxna stadie, i förstadiet eller i mitten av dess groddstadie. Plantor som precis övergått från grodd till vuxet stadie blev däremot inte alltid identifierade korrekt.

Städerna växer och samtidigt ökar efterfrågan på närodlade och ekologiska grödor. För att klara av att producera närodlat och mer hållbart skulle ett alternativ vara att odla i så kallade vertikala växthus. I Kiruna finns Sveriges största malmgruva som drivs av företaget LKAB vars olika processer leder till spillvärme. I Kiruna är klimatet kallt jämfört med större delen av Sverige och därför erfordras uppvärmning om odling ska kunna ske året runt i ett växthus. Examensarbetets uppgift är därför att undersöka hur man kan utnyttja spillvärme till ett vertikalt växthus i samband med en ny kontorsbyggnad på LKABs gruvområde. LKABs nya kontorsbyggnad har ett kvadratiskt avtryck på marken med ett hörn i sydlig riktning. Fördelningen mellan växthus och kontor kan förenklas genom att kvadraten delas på diagonalen där den södra halvan är växthus och den norra halvan kontor. Eftersom solförhållandena för odling är speciella i Kiruna har växthusets väggar en lutning som är anpassad efter solens låga infallsvinkel vilket gör att växthusets area minskar med varje våningsplan. Som yttermaterial till växthuset används glas och som stommaterial används stål. Ett hydroponiskt odlingssystem används där plantorna sätts direkt i en cirkulerande näringslösning och på så sätt kan systemet utformas med horisontella odlingsrör i flera vertikala odlingsplan. För uppvärmning av växthuset kommer spillvärme från LKABs verksamhet att utnyttjas, i examensarbetet undersöks två olika alternativ av spillvärmekällor och resultatet är att båda de alternativ som undersökts kan utnyttjas för uppvärmning av hela växthusdelens volym.
While the cities are expanding the demand for locally grown and organic crops is increasing. To be able to produce locally and more sustainable crops, one option could be to grow in a so-called vertical greenhouse. In Kiruna the largest ore mine in Sweden is operated by the company LKAB. Various processes in the mining industry lead to waste heat. In Kiruna, the climate is cold compared to most parts of Sweden, and therefore requires heating for the cultivation to be able to take place all year round in a greenhouse. The project’s task is to explore how to utilize waste heat from the mine to a vertical greenhouse in the context of a new office building at LKAB's mining area. LKAB's new office building has a square footprint on the ground with one of the corners in the south direction. The division between the greenhouse and the office can be simplified by the square divided diagonally where the southern half is the greenhouse and the northern half the office. Since the sunlight is limited in Kiruna the greenhouse walls has been design to adjust to the sun’s low position. The sun’s low position requires a sloped facade in the south direction. The greenhouse’s floor area decreases with each floor. As the external material for the greenhouse glass is used and as framing material steel is used. A hydroponically system is used where the seedlings are put directly in a circulating nutrient solution and in this way the system can be designed with horizontal pipes in several vertical cultivated floors. The greenhouse will be heated with waste heat from LKAB's industry, the project examines two alternatives of waste heat sources, and the result is that both of the alternatives studied can be used to heat the entire volume of the greenhouse.

Pythium diseases are common in the greenhouse production of tobacco transplants and can cause up to 70% seedling loss in hydroponic (float-bed) greenhouses. However, the symptoms and consequences of Pythium diseases are often variable among these greenhouses. A tobacco transplant greenhouse survey was conducted in 2017 in order to investigate the sources of this variability, especially the composition and distribution of Pythium communities within greenhouses. The survey revealed twelve Pythium species. Approximately 80% of the surveyed greenhouses harbored Pythium in at least one of four sites within the greenhouse, including the center walkway, weeds, but especially bay water and tobacco seedlings. Pythium dissotocum, followed by P. myriotylum, were the most common species. Pythium myriotylum, P. coloratum, and P. dissotocum were aggressive pathogens that suppressed seed germination and caused root rot, stunting, foliar chlorosis, and death of tobacco seedlings. Pythium aristosporum, P. porphyrae, P. torulosum, P. inflatum, P. irregulare, P. catenulatum, and a different isolate of P. dissotocum, were weak pathogens, causing root symptoms without affecting the upper part of tobacco seedlings. Pythium adhaerens, P. attrantheridium, and P. pectinolyticum did not affect tobacco seeds or seedlings. The consequences of Pythium infection were more likely to be severe when they occurred during seed germination than at seedling emergence, or after plant stem elongation when seedling roots had started to grow into underlying nutrient solutions, depending on the species of Pythium. High and low variation was observed among isolates of P. dissotocum and P. myriotylum, respectively. Pythium myriotylum co-existed with multiple other Pythium or oomycete species in the same environments within tobacco greenhouses, and significant in vitro and/or in vivo interactions between P. myriotylum and some naturally co-existing species were revealed. Pythium porphyrae may have the potential to protect tobacco seeds and seedlings from P. myriotylum infection. Greenhouse Pythium control trials identified ethaboxam, mefenoxam, and copper ionization as potentially promising alternatives to etridiazole for Pythium disease management in tobacco transplant production. The outcomes of this project provide useful new information to better understand the composition, distribution, and diversity of Pythium communities in tobacco transplant greenhouses and to improve Pythium disease management for tobacco transplant production.
Doctor of Philosophy
Pythium diseases are common in tobacco transplant production and can cause up to 70% seedling losses in hydroponic (float-bed) tobacco transplant greenhouses. However, little is known about the composition and distribution of Pythium communities in tobacco transplant greenhouses. This project began with a tobacco transplant greenhouse survey, in which 12 Pythium species were recovered from center walkways, weeds, greenhouse bay water, and tobacco seedlings. Pythium dissotocum and P. myriotylum were the two types (species) of Pythium most commonly found in the survey. Pythium myriotylum, P. coloratum, and P. dissotocum were aggressive pathogens that suppressed seed germination and caused root rot, stunting, foliar chlorosis, and death of tobacco seedlings. Pythium aristosporum, P. porphyrae, P. torulosum, P. inflatum, P. irregulare, P. catenulatum, and an isolate of P. dissotocum, were weak pathogens causing root symptoms without affecting the upper part of tobacco seedlings. Pythium adhaerens, P. attrantheridium, and P. pectinolyticum did not affect tobacco seeds or seedlings. The symptoms caused by infection by Pythium species differed among host (tobacco) growth stages, except for the most aggressive species, P. myriotylum. High levels of variation were observed among isolates of P. dissotocum, in terms of vegetative growth rate (on V8 agar media) and aggressiveness on tobacco seed and seedlings. Pythium myriotylum was found to co-exist with multiple other Pythium or oomycete species (neighbor isolates) in the same environments within tobacco greenhouses. Significant interactions between P. myriotylum and some neighbor isolates were revealed, and these interactions significantly affect the consequences of P. myriotylum infection of tobacco seeds. Greenhouse Pythium control trials identified two chemical water treatments (ethaboxam and mefenoxam), and a non-chemical water treatment (copper ionization) as potentially promising alternatives to the current standard Pythium control (etridiazole) for Pythium disease management in tobacco transplant production. The outcomes of this project provide useful new information to both better understand the composition, distribution, and diversity of Pythium communities in tobacco transplant greenhouses and to improve Pythium disease management for tobacco transplant production.

Denna rapport behandlar en fallstudie i ett kandidatexamensarbete som utförts tillsammans med en livsmedelsbutik i Stockholmsområdet och som grundar sig i intervjuer, platsbesök och vetenskapliga artiklar. Där livsmedelsbutiken har ett intresse av att implementera en odling i form av ett hydroponiskt system direkt i sin butik.  I fallstudien har det undersökts hur implementering av odling i butik genom ett samarbete med ett odlingsföretag skulle fungera och se ut för butiken. Studien har begränsats till två olika odlingsföretag i Sverige, som har varsitt koncept på hur odlingen kan implementeras, gemensamt för dem är att de använder vertikal odling i form av hydroponiska system. Där det ena företaget erbjuder vertikal odling i en odlingscontainer och det andra vertikal odling inne i ett växthus. Båda företagens olika odlingskoncept har redan implementerats i två andra livsmedelsbutiker inom samma koncern som livsmedelsbutiken i Stockholm befinner sig i.  Fallstudien har genomförts genom att först skapa en bred bakgrund genom litteratursökningar i olika databaser kring relevanta nyckelord för att sedan genomföra intervjuer med båda odlingsföretagen och livsmedelsbutikerna. Därefter har kunskap och svar från respondenterna i intervjuerna sammanställts och ett förslag har tagits fram om vilket odlingsföretag som lämpar sig bäst för livsmedelsbutikens ändamål.  Resultatet visar att möjligheterna och fördelarna vid en implementering av hydroponisk odling för livsmedelsbutiken i Stockholmsområdet att implementera hydroponisk odling är flera och överväger till största del de möjliga utmaningarna. Dessutom gynnas flera av hållbarhetsmålen till livsmedelsbutikens koncern genom implementering av en hydroponisk odling i butiken. Vidare gynnas även några av de Förenta Nationernas Globala mål och även livsmedelsbutikens egna hållbarhetsmål.
This report is the result and outcome of a bachelor's thesis project conducted during the spring of 2021. The report presents the performed case study of a grocery store, in the area of Stockholm, where the company is aiming to implement a hydroponic self-cultivation inside their grocery store. The work is based on conducting interviews and reviewing established scientific articles in the field.  In the case study, it has been investigated how a potential collaboration between the grocery store and a cultivation company can be established. The study was limited to investigating two cultivation companies active on the Swedish market. These two cultivation companies have different solutions of how the cultivation can be implemented on the store area, but both offer vertical hydroponic solutions. Further, both systems of the individual cultivation companies’ have been implemented in other grocery stores that can be used as reference for validation of data.  The literature review of existing publications were conducted by searching in different databases by using the keywords of this work, for the researcher to increase knowledge to create guides for the interviews and for creating the theoretical frame of reference. Thereafter, literature findings and answers from the interviewees were compiled, analyzed and discussed to make a proposition of which cultivation company is best suited for a potential collaboration, with regard to the grocery stores’ wishes of implementing a hydroponic solution.  The results show that several of the grocery stores’ sustainability goals would benefit from a potential implementation of a self-cultivation. Also, implementing a hydroponic farm on the store area would increase the grocery store’s contribution towards achieving the Sustainable Development Goals.

O presente trabalho é um estudo da utilização da forragem hidropônica como opção para alimentação de ruminantes em épocas do ano em que há escassez de alimentos volumosos. O experimento foi realizado em ambiente protegido, no Instituto Federal do Rio Grande do Sul, em Sertão, Brasil, no ano de 2009, com o objetivo de avaliar o efeito da densidade de semeadura e da idade de colheita na produtividade e na composição bromatológica de milho produzido em substrato de feno de aveia. Adotou-se o delineamento experimental inteiramente casualizado, com quatro repetições, utilizando parcelas de 1,0 m2 (1,0 x 1,0 m). As densidades foram distribuídas em esquema fatorial (3 x 2), constituído de 3 densidades de semeadura (1,0; 2,0 e 3,0 kg.m-2). A fertirrigação foi usada do 3º ao 17º dia. Foram realizadas duas colheitas, aos 10 e 17 dias, onde foram determinadas a massa de matéria verde e seca (kg.m-2), a altura das plantas e os teores de PB, FDA, FDN e NDT. Os resultados foram submetidos à análise estatística pelo teste de Tukey ao nível de significância de 5%. Não houve diferença estatística para os valores obtidos pela análise bromatológica em relação às densidades de semeadura utilizadas. A massa de matéria seca aos 17 dias para a densidade de 3,0 kg.m-2 sofreu redução e diferenciou estatisticamente das demais. Para a utilização da forragem verde, a colheita pode ser realizada aos 17 dias (não houve diferença significativa em relação às densidades de semeadura de 2,0 e 3,0 kg.m-2).
The present work is a study of the use of hydroponic forage as an option for feeding ruminant during period of the year with food scarcity. The experiment was carried out in greenhouse, at Federal Institute of Rio Grande do Sul in Sertão, Brazil, in 2009, with the objective of evaluating the effect of the sowing density and crop age in the productivity and bromatological composition of maize under hydroponic system, produced under oat hay substrate. The statistical design was completely randomized, with four replications, using plots of 1,0 m2 (1,0 x 1,0 m). The densities were distributed in outline factorial (3 x 2), constituted of 3 sowing densities (1.0, 2.0 and 3.0 kg.m-2). The fertirrigation was used from the 3rd to the 17th day. There were two harvests, at 10 and 17 days, which were determined the green and dry mass (kg.m-2), the plant height and the PB, FDA, FDN and NDT content. The results were submitted to the statistical analysis by the Tukey test (P > 0.05). There was no statistical difference between values obtained by the bromatological analysis related to the sowing densities. The dry matter at 17 days using the seeding rate of 3.0 kg.m-2 was statistical lower than others treatments. For the use of the green forage, the harvesting can be performed at 17 days (there was no significant difference in relation to seeding rates of 2.0 and 3.0 kg.m-2).

Шевченко, І. М. Оздоровлення сортів картоплі за використання біотехнологічних методів : випускна кваліфікаційна робота : 201 «Агрономія» / І. М. Шевченко ; керівник роботи О. Ю. Локоть ; НУ "Чернігівська політехніка", кафедра аграрних технологій та лісового господарства . – Чернігів, 2021. – 70 с.
Об’єктом досліджень є процеси оздоровлення картоплі від вірусної інфекції та прискореного розмноження безвірусного матеріалу в умовах гідропонної теплиці. Предметом дослідження є використання біотехнологічних методів в технології оздоровлення картоплі від вірусних хвороб. На сьогодні відомо про новітні технології отримання першого покоління міні бульб картоплі за використання гідропоніки. Гідропонне вирощування, є альтернативою більш традиційному процесу вирощування рослин у ґрунті. Використовуючи системи, засновані на вирощуванні рослин шляхом подачі води наповненої поживними речовинами, значно прискорює виробництво продукції. В господарстві ПрАТ НВО «Чернігівеліткартопля» успішно працює „Промислова гідропонна технологiя виробництва міні бульбоздоровленої картоплi”, яка закоефiцiєнтом розмноження перевищує iснуючi технологiї прискоренного розмноження в 5 – 10 разiв і забезпечує одержання від однієї оздоровленої пробіркової рослини, висадженої у гідропонну установку, за вегетаційний період 50 – 100 мінібульб масою 3 – 5 грамів. Це дозволяє відтворювати еліту за скороченою трьохрічною схемою, до того ж без добору клонів.
The object of research is the processes of recovery of potatoes from viral infection and accelerated reproduction of virus-free material in a hydroponic greenhouse. The subject of research is the use of biotechnological methods in the technology of recovery of potatoes from viral diseases. Today we know about the latest technologies for obtaining the first generation of mini potato tubers using hydroponics. Hydroponic cultivation is an alternative to the more traditional process of growing plants in the soil. Using systems based on growing plants by supplying water filled with nutrients, significantly accelerates production. In the economy of PJSC NPO "Chernigivelitkartoplya" successfully works "Industrial hydroponic technology for the production of mini-bulb potatoes", which by the coefficient of reproduction exceeds the existing technologies of accelerated reproduction in 5 - 10 times and provides from one healthy, - 100 minibulbs weighing 3 - 5 grams. This allows you to reproduce the elite on a shortened three-year scheme, in addition, without the selection of clones.

The purpose of this project is to create a fully automatedgreenhouse that can produce year-round crops, using sensorsand actuators. Temperature in both water and air,relative humidity, water level, nutrient level and pH are allmeasured with different sensors. Though only water level,pH and nutrients will be regulated. The greenhouse will berelying on a hydroponic growing technique, meaning thatthe growing is soil-less and will be done in water. Thismakes measuring and controlling said levels easier and alsominimizes water waste and makes for a more environmentalsystem. The main focus of this project is on regulating pHand nutrient levels of the water. The system has shown tobe stable and self regulating within the desired intervals fornutrient concentration and pH for growing basil.
Syftet med det här projektet är att skapa ett automatiserat växthus som kan producera grödor året runt med hjälp av sensorer och aktuatorer. Med olika sensorer mäts temperaturen i både vattnet och luften, relativa luftfuktigheten, vattennivå, pH- och näringsvärden. Dock kommer endast vattennivå, pH- och näringsvärden regleras. Växthuset använder sig av så kallad hydroponisk odling, vilket innebär att odlingen inte sker i jord utan i vatten. Detta underlättar bland annat mätningar och kontrollering av systemet men minimerar även vattenkonsumptionen och bidrar till ett mera miljövänligt system. Projektet kommer i huvudsak inrikta sig på reglering av pH och näringsnivåer av vattnet. Systemet har visats stabilt och har förmågan att reglera sig självt inom önskat intervall för näringskoncentration och pH för att odla basilika.

The goal of this study was to prove that aquaponic systems can produce lettuce of equal growth and quality compared to hydroponic lettuce production and to determine the stocking density of fish required for plant growth. Aquaponics is the integration of recirculating aquaculture and hydroponic plant production. The project had four objectives. The first objective was to determine the biomass of fish required for plant growth to develop a fish to plant density ratio. The second objective was to compare lettuce grown with aquaponic water and a hydroponic solution under the same environmental conditions. The third objective was to compare the quality of lettuce grown with aquaponics water plus nutrient supplementation with a hydroponic solution. The fourth objective was to determine the nitrogen dynamics in the aquaponic system and to compare the nutrient composition of lettuce grown with aquaponics water with nutrient supplementation and hydroponic solution. It was determined that under the specified environmental conditions 5 kg m⁻³ of Nile tilapia (O. niloticus) fed 2% of their body weight daily yields on average 4.7 kg m⁻² of lettuce (L. sativa cv. Rex) in 35 days. There was no significant difference (p ≤ 0.05) in biomass or chlorophyll concentration index in lettuce (L. sativa cv. Rex) grown with aquaponics water and nutrient supplements versus a hydroponic solution. The aquaponics solution generated equal biomass and chlorophyll concentration indexes compared to the hydroponic solution. Aquaponics water plus supplementation can yield L. sativa cv. Rex with equal biomass accumulation and chlorophyll concentration indexes compared to hydroponics lettuce. Nutrients added to the aquaponics system consisted of iron, manganese, and zinc. These nutrient concentrations became depleted in the aquaponics water over time and were not replenished via the fish feed. Dolomite was added to the aquaponics system every two weeks to increase the buffering capacity of the water and maintain optimal pH levels. Aquaponics lettuce had similar nutrient composition to hydroponic lettuce. One head of L. sativa cv. Rex (176.75 ± 31.03) will assimilate approximately 5.96 grams of nitrogen (3.38% per dry gram lettuce). One kilogram of fish will yield 6.4 lettuce heads (1,128 grams) and fixate 38.13 grams of nitrogen.

Greenhouse cultivation is a growing industry, especially in mild climates, much due to the ability toadjust the growing conditions and increased water utilization efficiency. The most important aspect onthe cultivation is the indoor temperature. The variation in temperature is due to the Swedish climatewhere the highest and lowest outdoor temperature respectively varies greatly during the year. To enableoptimal indoor climate additional heating is required during colder periods. Presently, most of theexisting greenhouses utilizes combustion of fossil fuels for heating, which contributes to the climatechange through the emissions of greenhouse gases. One way to circumvent this impact is to exchangethe fossil fuels with biogas. Combining biogas production and greenhouse cultivation enables synergiesand a more closed cycle of material flow can be achieved. However, this combination is rather immaturedue to lacking previous research, giving this report its main purpose, to examine the synergies andsustainability of combining a greenhouse with small-scale biogas production. Initially, an extensive literature study was carried out followed by a simulation based on the obtainedknowledge. The simulation was comprised of two greenhouses with different geometries, one with theshape of an arch with polyethylene-film cladding and the other with a sawtooth roof with glass cladding,both with two layers. The other properties such as internal area and volume are more or less the samefor the simulated greenhouses. Useful data such as outdoor temperature, rainfall and solar irradiationetc. was obtained for the city of Enköping, Sweden. The calculations for the models were carried out inthe program Microsoft Excel. In order to evaluate the feasibility of these models a reference greenhousewas studied, which had similar properties and conditions. The optimal temperature for tomato cultivation is 20° C, and to maintain this level over the entire yearit was found that the heat requirements were 89 500 kWh for the arched greenhouse and 94 400 kWhfor the sawtooth greenhouse. In comparison with the reference greenhouse, the heat requirement wasaround 200 kWh per m2 and year less in the simulated greenhouses. Furthermore, it was found thataround 31 800 kWh of cooling is required over the year (249 kWh per m2 and year) for the archedgreenhouse and 30 900 kWh per year (241 kWh per m2 and year) for the sawtooth greenhouse, to keepthe indoor temperature at 20 °C. Moreover, two to three possible harvests annually gives the yield of 3456-5184 kg tomatoes per year. Both the simulated greenhouses are feasible concepts, however thesawtooth greenhouse is a better option due to its increased longevity and lower contribution ofgreenhouse gas emissions over time. Furthermore, more research needs to obtain a fully closed cycle.

Controlled environment agriculture offers a solution to challenges including less available land, water deficits, and consumer demand for pesticide free produce. However, control of soil-borne diseases is a major limiting factor. The goal of this dissertation was to examine predictions of the hypothesis that border cells function to protect plant health by controlling microorganisms associated with plants grown in hydroponic culture. Border cells separate from root tips upon immersion in water, and appear to have important roles in the defense mechanisms of plant roots. The general objectives were (1) to study the delivery of border cells in hydroponics; (2) to evaluate interactions between border cells and microorganisms in hydroponics; and (3) to explore approaches to alter border cell production for improved root disease control. In this study it was confirmed that border cells can be released continuously into the solution of hydroponic culture suggesting that plants grown in this system may use extra energy in the production of new border cells. Free border cells interacted with microorganisms present in the hydroponic solution by secreting an extracellular capsule. Previous studies showed that proteins are a key component of this capsule, including lectins. The interaction of pea lectin and Nectria haematococca spores therefore was explored. Results demonstrated that pea lectin agglutinates fungal spores in a hapten-specific manner, and inhibits their germination. Lectin had no negative effect on root development suggesting that it could be used as a potential control for soil-borne diseases in hydroponics. To control the production of border cells, subsequent studies measured the impact of a transient exposure of root tips to different metabolites secreted by root caps and border cells. Exposure to specific metabolites altered the production of border cells without measurable effects on root growth and development. This is in contrast to results obtained with altered gene expression. For example, gene silencing of a border cell specific gene resulted in altered root growth.

Selenium (Se) is an essential element for human and livestock with antioxidant and anticancer characteristics. Although Se is not an essential element for plants, it has been reported that it can improve plant growth. This experiment was conducted at the Isfahan University of Technology in winter 2010. The experiment was factorial based on a completely randomized design (CRD) with 4 replications. Se was added to nutrient solution in 4 concentrations 2, 4, and 6 mg/l sodium selenite (Na2SeO3). Root volume, fresh and dry weights of shoots and roots, number and weight of fruits, chlorophyll content and photosynthesis traits (photosynthesis rate, stomata internal carbon dioxide (CO2) concentration, stomata conductance) were measured. Results showed that Se increased root dry weight. Fresh and dry weights of shoot increased in the 2 mg/l Se treatment and decreased at the higher level of Se. Chlorophyll content and photosynthesis rate were not affected by Se. Stomata internal CO2 concentration and stomata conductance decreased by Se addition. Overall, Se at 2 mg/l application rate was effective in some physiological characteristics of cucumber.

Moderne Präzisionsgartenbaulicheproduktion schließt hoch technifizierte Gewächshäuser, deren Einsatz in großem Maße von der Qualität der Sensorik- und Regelungstechnik abhängt, mit ein. Zu den Regelungsstrategien gehören unter anderem Methoden der Künstlichen Intelligenz, wie z.B. Künstliche Neuronale Netze (KNN, aus dem Englischen). Die vorliegende Arbeit befasst sich mit der Eignung KNN-basierter Modelle als Bauelemente von Klimaregelungstrategien in Gewächshäusern. Es werden zwei Modelle vorgestellt: Ein Modell zur kurzzeitigen Voraussage des Gewächshausklimas (Lufttemperatur und relative Feuchtigkeit, in Minuten-Zeiträumen), und Modell zur Einschätzung von phytometrischen Signalen (Blatttemperatur, Transpirationsrate und Photosyntheserate). Eine Datenbank, die drei Kulturjahre umfasste (Kultur: Tomato), wurde zur Modellbildung bzw. -test benutzt. Es wurde festgestellt, dass die ANN-basierte Modelle sehr stark auf die Auswahl der Metaparameter und Netzarchitektur reagieren, und dass sie auch mit derselben Architektur verschiedene Kalkulationsergebnisse liefern können. Nichtsdestotrotz, hat sich diese Art von Modellen als geeignet zur Einschätzung komplexer Pflanzensignalen sowie zur Mikroklimavoraussage erwiesen. Zwei zusätzliche Möglichkeiten zur Erstellung von komplexen Simulationen sind in der Arbeit enthalten, und zwar zur Klimavoraussage in längerer Perioden und zur Voraussage der Photosyntheserate. Die Arbeit kommt zum Ergebnis, dass die Verwendung von KNN-Modellen für neue Gewächshaussteuerungstrategien geeignet ist, da sie robust sind und mit der Systemskomplexität gut zurechtkommen. Allerdings muss beachtet werden, dass Probleme und Schwierigkeiten auftreten können. Diese Arbeit weist auf die Relevanz der Netzarchitektur, die erforderlichen großen Datenmengen zur Modellbildung und Probleme mit verschiedenen Zeitkonstanten im Gewächshaus hin.
One facet of the current developments in precision horticulture is the highly technified production under cover. The intensive production in modern greenhouses heavily relies on instrumentation and control techniques to automate many tasks. Among these techniques are control strategies, which can also include some methods developed within the field of Artificial Intelligence. This document presents research on Artificial Neural Networks (ANN), a technique derived from Artificial Intelligence, and aims to shed light on their applicability in greenhouse vegetable production. In particular, this work focuses on the suitability of ANN-based models for greenhouse environmental control. To this end, two models were built: A short-term climate prediction model (air temperature and relative humidity in time scale of minutes), and a model of the plant response to the climate, the latter regarding phytometric measurements of leaf temperature, transpiration rate and photosynthesis rate. A dataset comprising three years of tomato cultivation was used to build and test the models. It was found that this kind of models is very sensitive to the fine-tuning of the metaparameters and that they can produce different results even with the same architecture. Nevertheless, it was shown that ANN are useful to simulate complex biological signals and to estimate future microclimate trends. Furthermore, two connection schemes are proposed to assemble several models in order to generate more complex simulations, like long-term prediction chains and photosynthesis forecasts. It was concluded that ANN could be used in greenhouse automation systems as part of the control strategy, as they are robust and can cope with the complexity of the system. However, a number of problems and difficulties are pointed out, including the importance of the architecture, the need for large datasets to build the models and problems arising from different time constants in the whole greenhouse system.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Hydroponics forage is an alternative to producers who need quality food to their animals, at times of the year with low demand. It was carried out two experiments inside a polyethylene greenhouse (tunnel), in the Ecophysiology and Hydroponic Research Center (NUPECH), of the Federal University of Santa Maria, Brazil. The objective this work was to evaluate the production and bromatological nutrition in hidropoinc wheat forage. The experimental design was randomized complete block in a 2x4 factorial scheme, consisted of two nutrient solutions and four harvesting dates (4, 8, 12 and 16 days after emergence). In the firts experiment, it was evaluated two inorganic nutrient solution: SNN- NEVES (2001) solution and SNS- SANTOS et al. (2004) solution, and nitrate content was determined in wheat forage. In second experiment, the nutrients solutions evaluated were: SNS inorganic nutritive solution according to SANTOS et al., (2004) s recommendation, SNSC organic nutritive solution partly corrected attending SANTOS et al., (2004) s recommendation. It was not observed interaction (P 0.05) between sowing densities and harvest date for the variables dry mat ter (DM), crude protein (CP), soluble protein (SP), acid detergent fiber content (ADF), neutral detergent fiber content (NDF), lignine (LIG) and in vitro digestibility of dry matter (IVDDM). The hydroponic wheat forage cultivated with the SNS solution presented higher dry mass production and lower neutral detergent fiber content. It was observed decrease in dry matter production and digestibility in vitro and increase in nitrate content when delaying the harvesting dates. In the second experiment, it was observed interaction (P< 0.05) between nutrients solutions and harvest date for DM, CP, SP and NDF. The variables one presented square regression in relation to increase in harvest date, with positve response in DM and negative in CP, SP and NDF, for SNS and SNSC nutrient solution. It was observed increase in ADF and LIG and decrease in IVDDM content when delaying the harvesting dates. The superior value of IVDDM was obtained in forage produced with SNS solution in relation SNSC. The of ADF and LIG substance did not presented significant difference (P<0.05) among the SNS and SNSC solutions. The organic solution of bovine vermicompost besides offering the hydroponics forage production of good nutritional quality of wheat, it allows the use of residue produced in property, decreasing the production cost of nutritive solution. In the experiments, the best bromatolical characteristics of hydroponic wheat forage were verified with harvest at 8 - 12 days after sowing.
A utilização da forragem hidropônica é uma opção para atender às dificuldades de produção de pecuaristas, que não dispõem de quantidade e qualidade nutricional nos alimentos, a serem ofertados para animais em épocas do ano com baixa demanda. Neste sentido, foram conduzidos dois experimentos em ambiente protegido (túnel alto), na Universidade Federal de Santa Maria (UFSM) RS, no ano 2004. O trabalho objetivou avaliar a produção e qualidade nutricional da forragem hidropônica de trigo, cultivada com diferentes soluções nutritivas identificando a idade ideal de colheita. O delineamento experimental utilizado foi blocos ao acaso, distribuído em esquema fatorial 2x4, constituído por duas soluções e quatro idades de colheita (4, 8, 12 e 16 dias após a semeadura). No primeiro experimento as soluções avaliadas foram inorgânicas: SNN- solução descrita por NEVES (2001) e SNS- solução proposta por SANTOS et al., (2004), procedendo-se a analise do nitrato. No segundo experimento, as soluções nutritivas foram uma inorgânica, SNSsolução SANTOS et al., (2004), e a outra orgânica (vermicomposto bovino) parcialmente corrigida para atender recomendação de SANTOS et al., (2004). A interação entre soluções nutritivas (SNN e SNS) e idades de colheita não foi significativa (P 0,05) para as variáveis fitomassa seca (FS), proteína bruta (PB), proteína solúvel (PS), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), lignina (LIG) e digestibilidade in vitro da fitomassa seca (DIVFS). A forragem hidropônica de trigo cultivada com a solução SNS apresentou maior produção de FS e menor teor de FDN. O aumento no intervalo de tempo da idade de colheita proporcionou redução na produção de FS e na DIVFS e aumento no teor de nitrato. No segundo experimento, foi observada significância (P<0,05) entre a interação das soluções nutritivas (SNS e SNSC) e idades de colheita para as variáveis: FS, PB, PS e FDN. As variáveis ajustaram-se a equação de regressão quadrática em função da idade de colheita, sendo positiva para FS e negativa para PB, PS e FDN, tanto para a SNS quanto SNSC. O aumento no intervalo de tempo da idade de colheita na produção de forragem hidropônica determinou incremento linear no teor de FDA e LIG, e diminuição linear da DIVFS. A forragem cultivada com SNS apresentou teor superior DIVFS em relação à SNSC. O teor de FDA e LIG não apresentou diferença significativa (P>0,05) entre as soluções. A solução orgânica de vermicomposto bovino proporcionou a produção de forragem hidropônica de trigo de boa qualidade nutricional. Nos experimentos, concluiu-se que a colheita seja realizada entre 8 - 12 dias, principalmente devido aos bons teores protéicos sem o comprometimento do menor teor de FS e de sua digestibilidade.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
A adequaÃÃo do microclima das estufas Ãs necessidades das culturas tornou-se um fator de suma importÃncia para o bom desenvolvimento das culturas no cultivo protegido, sendo que em determinados horÃrios as temperaturas internas se elevam podendo reduzir a fotossÃntese. Para isso, podem ser utilizadas tecnologias alternativas que adequem as temperaturas as necessidades das culturas, tais como o uso de telas de sombreamento, principalmente para a reduÃÃo da temperatura nos perÃodos mais quentes do dia. Sendo assim, o objetivo deste trabalho foi avaliar o efeito de diferentes tipos de telas de sombreamento instaladas internamente nas estufas, logo abaixo da cobertura, sobre o crescimento de duas variedades de alface do tipo crespa (Marianne e VerÃnica), em um sistema de produÃÃo hidropÃnico em NFT (TÃcnica de Fluxo Laminar). O experimento foi conduzido em estufas cobertas com filme PEBD de 150 Âm, que apresentavam os seguintes tratamentos: ambiente sem uso de tela como subcobertura (ST), ambiente com tela termorrefletora como subcobertura (TC), ambiente com tela de sombreamento preta como subcobertura (TP) e ambiente com tela vermelha como subcobertura (TV). Para avaliar a modificaÃÃo ambiental ocasionada pelo uso do filme PEBD e das telas, foram instalados, em cada estufa e no ambiente externo, termo-hidrÃmetros data loggers que registravam as variÃveis ambientais (temperatura e umidade relativa) a cada 30 minutos durante todo o perÃodo experimental. Posteriormente, foram calculados os graus dia acumulados de cada ambiente. Para analisar as alteraÃÃes nos padrÃes de resposta das plantas aos diferentes ambientes de cultivo, foram realizadas cinco coletas de plantas durante o perÃodo do experimento, sendo coletadas ao acaso, vinte plantas por tratamento. As plantas retiradas das bancadas eram repostas por outras vindas das bancadas de reposiÃÃo. ApÃs a coleta das plantas, as mesmas eram levadas ao laboratÃrio para realizaÃÃo das mediÃÃes de peso seco de raiz, caule e folhas, e da Ãrea foliar. Essas informaÃÃes foram utilizadas para estimar as variÃveis morfolÃgicas. Os resultados indicaram que o uso das telas como subcobertura afetou o ambiente no interior das estufas, principalmente a temperatura e a umidade relativa do ar, onde o uso das telas termorrefletora e preta reduziu a temperatura mÃxima em 4,7 e 3,6ÂC, respectivamente, com relaÃÃo ao ambiente que nÃo usava tela como subcobertura (ST). Em relaÃÃo ao acÃmulo de graus dia, o ambiente ST e TV apresentaram comportamentos bem similares, contudo os ambientes TC e TP apresentaram um menor acÃmulo tÃrmico em relaÃÃo a ST e TV. Quanto Ãs alteraÃÃes morfolÃgicas ocasionadas pelas modificaÃÃes ambientais foi possÃvel constatar que o uso das telas termorrefletora e preta influenciou de forma positiva o nÃmero de folhas, o nÃmero de folhas maiores que 10 cm e o Ãndice de Ãrea foliar. TambÃm foi possÃvel observar que as variÃveis, nÃmero de folhas, nÃmero de folhas maiores que 10 cm, Ãndice de Ãrea foliar, taxa de crescimento absoluto e taxa de assimilaÃÃo lÃquida ajustaram-se, com elevados Ãndices de determinaÃÃo, a uma equaÃÃo sigmoidal com trÃs parÃmetros. Enquanto que as variÃveis, razÃo de peso foliar, razÃo de Ãrea foliar, Ãrea foliar especÃfica e taxa de crescimento relativo apresentaram ajuste polinomial de 3Â grau. De modo geral, o uso das telas termorrefletora e preta proporcionou uma melhoria de alguns fatores primordiais ao comÃrcio das plantas (nÃmero de folhas maiores que 10 cm e IAF), porÃm nÃo se pode afirmar que tais condiÃÃes sejam significativas para todas as Ãpocas do ano, fazendo-se necessÃrios mais estudos em outras Ãpocas do ano.
The adequacy of the microclimate of greenhouses to the needs of crop, has become a very important factor for the proper development of protected crops, times and in certain internal temperatures rise and may reduce photosynthesis.For this alternative technologies can be used to suit the needs of temperatures cultures, such as the use of shading screens, particularly for reducing the temperature in the warmer periods of the day. Therefore, the objective of this study was to evaluate the effect of different types of shading screens installed inside the greenhouses, just below the roof, on the growth of two varieties of lettuce crisp (Marianne and Veronica), in a production system in NFT hydroponic (Laminar Flow Technique). The experiment was conducted in greenhouses covered with LDPE film of 150 micron, which had the following treatments: environment without using the screen as undercoverage (ST), ambient thermal reflector screen as undercoverage (TC), Environment shade cloth as black undercoverage (TP) and environment as undercoverage red screen (TV). To assess the environmental changes caused by the use of LDPE film and screens were installed in each greenhouse and an outdoor thermo-hygrometer data loggers that recorded the environmental variables (temperature and relative humidity) every 30 minutes throughout the period of Experimental. Subsequently, we calculated the accumulated degree days for each environment. To analyze changes in patterns of plant response to different environmental conditions, there were five samplings during the experiment, and randomly collected twenty plants per treatment. The plants were removed from the benches replaced by others coming from the stands replacement. After collecting the plants, they were brought to the laboratory for measurement of dry weight of root, stem and leaves, and leaf area. This information was used for estimating of variable morphological. The results indicated that the use of screens as undercoverage affected the environment inside the greenhouse, especially temperature and relative humidity, where the use of thermal reflector and black screens reduced the maximum temperature at 4.7 and 3.6 Â C, respectively, with the environment that was not on screen as undercoverage (ST). Regarding the accumulation of degree days, the environment and TV ST showed very similar behavior, however environments CT and VT had a lower thermal accumulation in relation to TS and TV. As for the morphological changes caused by environmental changes, we determined that the use of thermal reflector screens and black influenced, positively, the number of leaves, leaf number larger than 10 cm and the leaf area index. It was also observed that the variables, number of leaves, leaf number larger than 10 cm, leaf area index, absolute growth rate and net assimilation rate were adjusted, with high levels of determination, a sigmoidal equation with three parameters. While the variables, leaf weight, leaf area ratio, specific leaf area and relative growth rate showed a better fit 3rd degree polynomial. In general, the use of thermal reflector and black screens provided an improvement of some key factors to trade in plants (number of leaves greater than 10 cm and LAI), however, it is not possible to say that these conditions are significant for all seasons , making it necessary more study at other times of the year.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2003.
Appendix consists of reprints and manuscripts of five papers co-authored with others. Includes bibliographical references. Also partially available online in PDF format; online version lacks appendix.

SALES, Francisco Alexandre de Lima. Microclima na produção de alface hidropônica em ambiente protegido utilizando telas de sombreamento como subcobertura. 2012. 96 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2012.
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The adequacy of the microclimate of greenhouses to the needs of crop, has become a very important factor for the proper development of protected crops, times and in certain internal temperatures rise and may reduce photosynthesis.For this alternative technologies can be used to suit the needs of temperatures cultures, such as the use of shading screens, particularly for reducing the temperature in the warmer periods of the day. Therefore, the objective of this study was to evaluate the effect of different types of shading screens installed inside the greenhouses, just below the roof, on the growth of two varieties of lettuce crisp (Marianne and Veronica), in a production system in NFT hydroponic (Laminar Flow Technique). The experiment was conducted in greenhouses covered with LDPE film of 150 micron, which had the following treatments: environment without using the screen as undercoverage (ST), ambient thermal reflector screen as undercoverage (TC), Environment shade cloth as black undercoverage (TP) and environment as undercoverage red screen (TV). To assess the environmental changes caused by the use of LDPE film and screens were installed in each greenhouse and an outdoor thermo-hygrometer data loggers that recorded the environmental variables (temperature and relative humidity) every 30 minutes throughout the period of Experimental. Subsequently, we calculated the accumulated degree days for each environment. To analyze changes in patterns of plant response to different environmental conditions, there were five samplings during the experiment, and randomly collected twenty plants per treatment. The plants were removed from the benches replaced by others coming from the stands replacement. After collecting the plants, they were brought to the laboratory for measurement of dry weight of root, stem and leaves, and leaf area. This information was used for estimating of variable morphological. The results indicated that the use of screens as undercoverage affected the environment inside the greenhouse, especially temperature and relative humidity, where the use of thermal reflector and black screens reduced the maximum temperature at 4.7 and 3.6 ° C, respectively, with the environment that was not on screen as undercoverage (ST). Regarding the accumulation of degree days, the environment and TV ST showed very similar behavior, however environments CT and VT had a lower thermal accumulation in relation to TS and TV. As for the morphological changes caused by environmental changes, we determined that the use of thermal reflector screens and black influenced, positively, the number of leaves, leaf number larger than 10 cm and the leaf area index. It was also observed that the variables, number of leaves, leaf number larger than 10 cm, leaf area index, absolute growth rate and net assimilation rate were adjusted, with high levels of determination, a sigmoidal equation with three parameters. While the variables, leaf weight, leaf area ratio, specific leaf area and relative growth rate showed a better fit 3rd degree polynomial. In general, the use of thermal reflector and black screens provided an improvement of some key factors to trade in plants (number of leaves greater than 10 cm and LAI), however, it is not possible to say that these conditions are significant for all seasons , making it necessary more study at other times of the year.
A adequação do microclima das estufas às necessidades das culturas tornou-se um fator de suma importância para o bom desenvolvimento das culturas no cultivo protegido, sendo que em determinados horários as temperaturas internas se elevam podendo reduzir a fotossíntese. Para isso, podem ser utilizadas tecnologias alternativas que adequem as temperaturas as necessidades das culturas, tais como o uso de telas de sombreamento, principalmente para a redução da temperatura nos períodos mais quentes do dia. Sendo assim, o objetivo deste trabalho foi avaliar o efeito de diferentes tipos de telas de sombreamento instaladas internamente nas estufas, logo abaixo da cobertura, sobre o crescimento de duas variedades de alface do tipo crespa (Marianne e Verônica), em um sistema de produção hidropônico em NFT (Técnica de Fluxo Laminar). O experimento foi conduzido em estufas cobertas com filme PEBD de 150 µm, que apresentavam os seguintes tratamentos: ambiente sem uso de tela como subcobertura (ST), ambiente com tela termorrefletora como subcobertura (TC), ambiente com tela de sombreamento preta como subcobertura (TP) e ambiente com tela vermelha como subcobertura (TV). Para avaliar a modificação ambiental ocasionada pelo uso do filme PEBD e das telas, foram instalados, em cada estufa e no ambiente externo, termo-hidrômetros data loggers que registravam as variáveis ambientais (temperatura e umidade relativa) a cada 30 minutos durante todo o período experimental. Posteriormente, foram calculados os graus dia acumulados de cada ambiente. Para analisar as alterações nos padrões de resposta das plantas aos diferentes ambientes de cultivo, foram realizadas cinco coletas de plantas durante o período do experimento, sendo coletadas ao acaso, vinte plantas por tratamento. As plantas retiradas das bancadas eram repostas por outras vindas das bancadas de reposição. Após a coleta das plantas, as mesmas eram levadas ao laboratório para realização das medições de peso seco de raiz, caule e folhas, e da área foliar. Essas informações foram utilizadas para estimar as variáveis morfológicas. Os resultados indicaram que o uso das telas como subcobertura afetou o ambiente no interior das estufas, principalmente a temperatura e a umidade relativa do ar, onde o uso das telas termorrefletora e preta reduziu a temperatura máxima em 4,7 e 3,6ºC, respectivamente, com relação ao ambiente que não usava tela como subcobertura (ST). Em relação ao acúmulo de graus dia, o ambiente ST e TV apresentaram comportamentos bem similares, contudo os ambientes TC e TP apresentaram um menor acúmulo térmico em relação a ST e TV. Quanto às alterações morfológicas ocasionadas pelas modificações ambientais foi possível constatar que o uso das telas termorrefletora e preta influenciou de forma positiva o número de folhas, o número de folhas maiores que 10 cm e o índice de área foliar. Também foi possível observar que as variáveis, número de folhas, número de folhas maiores que 10 cm, índice de área foliar, taxa de crescimento absoluto e taxa de assimilação líquida ajustaram-se, com elevados índices de determinação, a uma equação sigmoidal com três parâmetros. Enquanto que as variáveis, razão de peso foliar, razão de área foliar, área foliar específica e taxa de crescimento relativo apresentaram ajuste polinomial de 3º grau. De modo geral, o uso das telas termorrefletora e preta proporcionou uma melhoria de alguns fatores primordiais ao comércio das plantas (número de folhas maiores que 10 cm e IAF), porém não se pode afirmar que tais condições sejam significativas para todas as épocas do ano, fazendo-se necessários mais estudos em outras épocas do ano.

As the world population continues to grow, it will be challenging to manage resources, reduce environmental pollution and maintain growing demand for food production. Controlled environment agriculture (CEA) is a novel solution to reduce freshwater use in agriculture, minimize environmental pollution from agriculture sector, and meet the growing food demand. CEA allows for the year-round cultivation in inhospitable climatic conditions. Hydroponics is a common method of growing crops in CEA, where plants grow in a solution enriched with nutrients and oxygen. The technique significantly reduces water use and fertilizer run-off during production. In the United States, lettuce is one of the most important crops grown using hydroponics.

Hydroponic production uses several methods to grow lettuce including nutrient film technique (NFT) and constant flood table (CFT). Moreover, several cultivars of lettuce are grown in the Midwest. There is a lack of knowledge on whether optimal fertilizer concentrations change depending on the cultivar or hydroponic production system. Little information is known about the suitability of a cultivar to a specific method of hydroponic production. For year-round lettuce production in hydroponics, supplemental lighting (SL) and heating are required in the Midwestern regions of the U.S. The energy requirements for SL and heating can be too costly in winter for some growers to produce crop year-round. In addition to light quantity, spectral composition of light can impact growth. Heating the root zone to produce a micro-climate may be more efficient than heating the entire greenhouse and possibly reduce overall heating costs. However, information on spectral composition of light and the efficacy of root zone heating is unclear, at best. Certain cultivars that can tolerate cold stress can be more suitable in the U.S. Midwest during winter. Lettuce cultivar screening for yield under cooler environments is limited.

A completely customizable hydroponic production system that can aid in conducting research related to above-mentioned issues was built as a part of my Master of Science program. Using this system, 24 popular cultivars from four lettuce groups were evaluated for productivity during summer/fall under different concentrations of fertilizer solution, and in two production methods including NFT and CFT during spring. In addition, yield of all 24 cultivars were evaluated under 10, 15.5 and 21.1 °C in a growth chamber. The eight best performing cultivars from the summer/fall trial were evaluated during the winter in a greenhouse with the addition of SL and root zone heating with minimal ambient air heating.

Results indicated that the lowest level of electrical conductivity (EC) of the fertilizer solution used (1.3 dS·m^-1) resulted in highest yield, regardless of cultivar or method of production. Among the 24 cultivars; Red Sails (Leaf), Salvius (Romaine), Cedar (Oakleaf), and Adriana (Butterhead) had the highest yields among each group during summer. Growth chamber study indicated that Dragoon, Adriana, New Fire Red and Red Sails cultivars had higher yields than other cultivars under cooler (10 and 15.5 °C) air temperature conditions. In the winter study, lettuce cultivars did not reach harvestable size even after 40 days of growth without SL and root zone heating. Supplemental light composition significantly affected lettuce growth with higher yield under Purple (with higher proportion of red) than White LED lighting. Commercially acceptable lettuce could be produced using root zone heating. In general, plants grown under CFT yielded higher than those grown under NFT in the winter trial. Among the cultivars, Salvius, Black Seeded Simpson, Cedar, and Red Sails performed better under SL and root zone heating during winter.

Agribusiness advocates claim that modern agro-technology has led to higher per hectare yields. In particular, hydroponic greenhouse agriculture is advanced as a new and particularly productive approach to high output farming. This may contribute to the belief that agricultural land can be urbanized because human ingenuity is seemingly developing substitutes for the lost soil. This thesis challenges this assumption by examining agricultural technology from an ecological perspective. It uses the concept of the ecological footprint (or appropriated carrying capacity) to compare the productivity of hydroponic agriculture with that of conventional open field operations. I assess and compare the biophysical inputs required by these operations to produce 1000 tonnes of tomatoes. These figures are then translated into corresponding land areas (in various categories) necessary to produce the required biophysical inputs. In contrast to common belief, hydroponic operations require 14 – 21 times more land than conventional open field operations to produce the same output (including the land directly occupied by the farms). This case study demonstrates the merits of appropriated carrying capacity analysis for assessing progress toward sustainability. It shows that hydroponic agriculture is a prime example of apparent economic success which is, in fact, ecologically unsustainable. There is no reason for confidence that we can pave over our agricultural lands just yet! Finally, this study demonstrates that the apparent yields of hydroponic greenhouse agriculture are partially a reflection of under priced resource inputs, a form of subsidy which is not sustainable.

The chosen project originated as a response to humanity’s need to eat, and the agricultural processes necessary to feed the global population. The proposed solution will investigate the connection of physically and meta-physically dissociated elements, in order to create responsive architecture. The aim is to steer away from a mono-functional building and design typologies and to strive towards creating architecture that will address the needs of the public. The chosen project investigates future and current solutions for the production of food in urban environments. The scales of investigation range from microscopic research to the implementation and monitoring of skills transferred into the community. The proposed facility is thus composed out of various different programs, each with its own specific requirements. The composition can broadly be divided into scientific research facilities, a greenhouse complex and a public exhibition centre. It is unnecessary for the pragmatic and complex nature of the building to undermine the spatial expression. In the proposed facility, pragmatic limitations informed the design process, but did not govern the outcome. Instead, the limitations fuelled alternative problem solving, which in turn produced creative solutions. Thus, the building accepts that it is pragmatic in program, and compensates accordingly in order to create inviting spaces for people using the facility on an everyday basis. Copyright
Dissertation (MArch(Prof))--University of Pretoria, 2010.
Architecture
unrestricted