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Växthuset är en idrottshall kombinerad med en hydroponisk odling i centrala Järna. Det stora idrottshallsrummet är 46x32 meter och tillräckligt stort för att hålla i internationella tävlingar i flera sporter. På idrottshallens takbjälkar vilar den hydroponiska odlingen där olika grödor gror i inerta material genom tillförsel av näringsberikat vatten som cirkuleras genom odlingen. Förutom sportutrymme och odlingsgolv så innehåller byggnaden utrymmen för utbildning, kontor och fröodling samt en restaurang som tillagar grödorna från odlingen. I Järna bor över 9000 invånare som ska samsas om två idrottshallar under kvällstid, resultatet blir att många tvingas avstå från sport eller köra bil till en annan tätort och ingen av dessa alternativ är hållbara ur en social, ekonomisk eller ekologisk synpunkt. Jag vill öka tillgängligheten till idrott och möjligheten att anordna evenemang för sport i staden samt skapa en mötesplats för befolkningen. Genom att ta in en liten del av jordbruket i Järnas tätort skapas en koppling mellan det urbana och det rurala på platsen. Att förstå mattillverkningen skapar respekt för jordbruket och en ökad medvetenhet om matens värde. / Greenhouse is a sport shall combined with a hydroponic greenhouse in central Järna. The sports floor is 46x32 m which is big enough to host international contests in multiple sports. The hydroponics rests on the sports halls ceiling beams and grows different types of crops in inert material by supply of nutritionally enriched water. In addition to the sports hall and the cultivation floor the building also contains lecture halls and a study kitchen, office and a restaurant that uses the crops from the greenhouse in their menu. The population of Järna is over 9000 people and there are only two sports halls in the area and they are both only available after the school day is over. Therefore, many are forced to refrain from sports all together or drive to another area and non of these options are sustainable in a social, economical or ecological point of view. I want to increase availability to sports and sport events in Järna and create a public space for the people of Järna. By adding a small part of agriculture in central Järna a link is created between the urban and the rural on the site. Understanding the food production and its process builds a respect for the hard work put in and an increased awareness of the value of food.

Experiments were conducted with tomato under shade netting and with lettuce in a vertical hydroponic system at the Hatfield Experimental Farm, University of Pretoria. The objectives of the study were: 1. To evaluate the effect of different types of shade netting on tomato production 2. To develop a vertical hydroponic system for lettuce production which would be suitable for use by small-scale farmers. In the tomato trial the highest number of fruit per plant (47) was produced under 12% white shade and 40% black shade nets, and the lowest fruit number (35) was produced under 30% black net. The highest yield of 6.2 kg per plant was obtained under the 18% white net while 30% black net produced the lowest yield of 3.9 kg per plant. The test yield of lettuce grown in plastic tubes with eight vertically arranged plant positions were obtained with a continuous high flow rate of the nutrient solution. However, a simplified manual system where the nutrient solution was delivered by gravity from a small reservoir tank resulted in comparable yields. / Dissertation (M Inst Agrar (Agronomy))--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted

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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.

Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Kimberly A. Williams / Liquid organic fertilizers and microbial inoculants of beneficial microorganisms are garnering interest from commercial greenhouse growers who seek to produce crops more sustainably, but research about their efficacy is limited and results are conflicting. This research focused on comparing the effect of microbial inoculant addition in two soilless crop production systems under organic versus conventional fertilization. Two experiments were conducted with impatiens (Impatiens walleriana) in a peat-based substrate and four experiments were conducted with butterhead lettuce (Latuca sativa) in nutrient film technique (NFT) hydroponics. In the impatiens studies, nitrogen, phosphorus, and potassium were incorporated pre-plant equally across treatments using OsmocoteTM, or organic fertilizers Bloodmeal or Feathermeal. An inorganic constant liquid feed (CLF) was also evaluated. Microbial inoculants that contained a variety of beneficial species, including Bacillus spp. and Trichoderma spp. were drench-applied at the beginning of the cropping cycle. Impatiens growth was comparable between the nutrient regimens in one of the studies. CO2 respiration was measured on substrate samples. At a 5X application rate, inoculants contributed to subtle increases in plant growth in organic treatments, but microbial activity was unaffected as measured by CO2 respiration. However, organic nutrient sources contributed to higher CO2 respiration at day 7 of the production cycle compared to inorganic nutrient sources. The hydroponic trials consisted of inorganic and organic nutrient regimens, evaluated with and without microbial inoculant addition. Nutrient analyses and CO2 respiration of the nutrient solutions were collected. Use of inoculants resulted in increased plant growth when used in organic nutrient regimens in some trials. Plant dry weight and CO2 respiration in the inorganic nutrient regimens were increased in certain instances with inoculant addition. No differences in mycorrhizal root colonization were observed in either nutrient regimen with mycorrhizal inoculant addition. Petiole NO3-N concentration of lettuce plants grown with inorganic nutrient sources was greater than that of plants in organic regimens. Organic fertilizers and inoculant products resulted in comparable or positive impacts on plant growth and food crop quality in some treatment scenarios in these studies. The specific circumstances of crop production systems dictate whether plant growth response may occur from inoculant incorporation.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Horticulture in the Faculty of Applied Sciences at the Cape Peninsula University of Technology 2013 / This study evaluated the effects of different pH levels and supplementary phosphorous concentrations on Salvia chamelaeagnea grown in hydroponics. The treatments consisted of 12 treatments of 4 differing nutrient solutions offering: low concentration of supplementary P (control), balanced concentration of supplementary P, moderate concentration of supplementary P and a high concentration of supplementary P at 3 differing pH levels. Each treatment was replicated 10 times. The objectives of this study were to asses the effect of supplementary phosphorous concentrations and 3 different pH levels on the growth, development and chlorophyll responses of Salvia chamelaeagnea grown hydroponically. Growth and development was recorded by measuring weekly heights, numbers of basal shoots, stem diameters and the number of branches, while root length and wet and dry weights of roots and shoots were measured post harvest. Chlorophyll responses were recorded by measuring weekly SPAD-502 measurements while post harvest DMSO analysis of chlorophyll A, B and total chlorophyll were recorded along with nutrient uptake levels of N, P,K, Ca, Mg, Na, Mn, Fe, Cu, Zn and B in the plant leaves. This study has shown that the use of a hydroponic nutrient system offering a moderate concentration of supplementary P at a pH level of 4 significantly influences the growth and development of Salvia chamelaeagnea grown in hydroponics. Plants treated with a pH level of 4 generally produced higher wet and dry shoot weights, root lengths, stem diameters, basal shoot numbers, branch numbers, and plant heights than that of the control and all treatments delivering nutrients at a pH level of 6 and 8. Although no one treatment offering supplementary P produced consistently high results, in most cases all the plants receiving supplementary P at a pH level of 4 outperformed the pH 6 and pH 8 treatments receiving the same amount of supplementary P. This indicates that at a pH level of 4 the mineral nutrient availability of a nutrient solution is at an adequate level for the growth and development of Salvia chamelaeagnea. Furthering studies into the effects of arbuscular mycorrhiza on the uptake of mineral nutrients, root morphology and growth and development are recommended.

Thesis (MTech (Horticultural Science))--Cape Peninsula University of Technology, 2016. / This aim of this study was to investigate the viability of growing P. tomentosum in deep water culture (DWC) hydroponics and to assess the effects of various methods of oxygenating the nutrient solution with regards to growth, development and chlorophyll responses. The experiment was conducted over a period of 74 days. In chapter 3, 16 different methods of oxygenation were applied to 9 replicates. The control had passive aeration. The treatments were made up of air-pumps, vortex oxygenators and the application of hydrogen peroxide (H2O2) at various frequency intervals; these were combined with each other and run as separate oxygenation methods.

Mineral nutrients have marked effects on plant health by providing the building blocks for plant growth, as well as for mitigating abiotic and biotic stress factors, particularly disease development. Even if mineral nutrition field studies are conducted to study pest management, they are at the mercy of complex soil, water, and climatic conditions not amenable to strict experimental control. Therefore, a hydroponic method of growing lettuce was developed and growth curves were established for the macronutrients nitrogen (N), phosphorus (P), and potassium (K). Lettuce plants were grown at varying levels of each nutrient: 2.5, 5, 10, 20, 40, 80, 160, and 320 mg N/L; 0.5, 1, 2, 4, 8, 16, 32 and 64 mg P/L; and 0, 2.5, 5, 10, 20, 40, 80 and 160 mg K/L. Due to inadequate results lettuce was grown again at 0, 10, 20, 40, 80, 160, 320 and 640 mg L K. Optimal levels of N, P, and K were 160 mg/L, 4.0 mg/L, and 80 mg/L respectively. C:N ratios were also looked at for the N experiment. The overall result was consistent with results from similar studies. Unlike similar hydroponic studies done with other plants, micronutrient levels did not become deficient at high phosphorus levels suggesting phosphorus toxicity. These growth curves can be used to test lettuce resilience to various biotic and abiotic stresses.

Silicon is a major component of most soils, and is found in significant concentration in plant tissue. Plants vary widely in the amount of silicon they take up, with some plants excluding it, and others using transporters to move the silicon from the soil into their roots. Early plant physiology studies were unable to determine conclusively whether silicon was essential to plant growth, but for some plants, most notably rice, it has proved to be important enough to justify fertilizing silicon deficient fields. Researchers at the USU Crop Physiology Lab tested the effect of silicon on wheat growth and seed yield components. One study was grown in buckets of peat moss, with half the buckets being stressed with low water. The other study was grown in hydroponic tubs, with half the tubs being stressed with high levels of salt. The results from these studies showed that silicon does increase wheat seed yield and vegetative mass. Wheat with low levels of silicon exhibited twisting of the awns and decreased roughness of leaf surfaces. Silicon also improved water efficiency of drought stressed plants, and affected the concentration of many micro- and macro-nutrients in leaf tissue.