The Pennsylvania State University the Graduate School College Of
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The Pennsylvania State University The Graduate School College of Agricultural Sciences GREENTOWERS: PRODUCTION AND FINANCIAL ANALYSES OF URBAN AGRICULTURAL SYSTEMS A Thesis in Horticulture by Jonathan Gumble 2015 Jonathan Gumble Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science August 2015 The thesis of Jonathan Gumble was reviewed and approved* by the following: Robert D. Berghage Associate Professor of Horticulture Thesis Co-Advisor Dan T. Stearns J. Franklin Styer Professor Thesis Co-Advisor Mark A. Gagnon Harbaugh Entrpreneurship Scholar & Entrepreneur Coordinator Andrew Lau Associate Professor of Engineering Rich Marini Professor of Horticulture Head of the Department of Horticulture *Signatures are on file in the Graduate School ii Abstract By the year 2050, the population of planet Earth is expected to reach over nine billion people. In the next 35 years, we will have the task of supporting an additional two billion lives on a planet that is already struggling to provide a stable and acceptable food supply as well as an effective means of food distribution. Estimates show that of the seven billion people living on planet Earth, 870 million suffer from hunger. The fight against world hunger is a complex, challenging, and multi-faceted issue that can only be fought through innovative solutions that address the multiple aspects comprising it. One of these aspects is simply limited access to food in urban neighborhoods and rural towns which are referred to as “food deserts”. These are prevalent throughout the United States and have resulted in food-insecure households. Solutions to limited access do exist today in the form of innovative growing on developed land. The use of controlled agricultural environments through the means of greenhouse structures, LED lights, hydroponics, aquaponics, and aeroponics have made this possible. Multiple companies have come into existence and have built their businesses out of providing these innovative growing systems or growing food through their utilization. Although these techniques and systems do exist, there is limited information and data on production yields both from the companies themselves as well as from existing scientific literature. GreenTowers, LLC is an Urban Agricultural Design Company that came into existence in the past three years as a result of Penn State University’s College of Agricultural Science’s 2012 Ag Springboard Competition. The four co-founders; Dustin Betz, Jared Yarnall-Schane, Michael Zaengle, and Jonathan Gumble have transformed GreenTowers from a student competition team, to a full-time business. GreenTowers’ mission is “to reconnect individuals with nature and with food to help consumers realize the interconnection shared between ecological systems and food systems”. This is primarily accomplished through the use of two innovative growing systems developed by the company; the Rotating Living Wall and Living Furniture. The goal of this master’s program through these sets of experiments was to understand not only the production potentials of these two systems, but the financial aspects as well to determine economic viability in specific case scenarios. The Rotating Living Wall was tested through the growing of 12 varieties of microgreens. Experiments were performed from June 2014 to June 2015 to understand differences in seasonal yields, differences in yields based on variety of microgreen, yield comparison to a traditionally grown microgreen control group; both on a yields per/trough method as well as a yields per/ft.² method, rotational timing, moving versus stationary growth, differences in growth based on media depth, and differences in production yields from supplemental lighting. iii Performance criteria were based on measuring fresh weight, dry weight, height, and SPAD-meter readings (soil plant analysis development). Differences in yields throughout seasons were significant as well as differences between the Rotating Living Wall systems compared to the control group. The use of LED supplemental lighting provided significant differences in yields throughout winter season growing. Rotational timing, media depth, as well as physical movement of plants showed minimal or no significant influence on yields. By establishing the potential revenues and various costs that are part of growing with the Rotating Living Wall system, financial viability was analyzed showing that these systems can be profitable when used in State College, PA, within certain operating parameters. Living Furniture, which is a small scale aesthetic aquaponics system, was tested through the course of ten trials to understand not only the yield potentials for a variety of microgreens, but the operating costs as well. Number of fish and fish food mass did not result in significant differences in production yields with chelated iron supplementation, but did result in significant differences for water chemistry (specifically concentrations of ammonia, nitrite, and nitrate). Water chemistry overall did prove to be better in the Living Furniture systems compared to a control setup tank with a standard mechanical filter. Chelated iron supplementation resulted in significant improvement for overall production of the systems; even resulting in the aquaponic systems surpassing the production yields from control-grown microgreens produced in a commercial potting mix. The research completed throughout these studies has not only provided a base line of operation for both these systems, but has also given insight into future studies and research that can be completed for further optimization and increased efficiency. Developed and improved growing systems may have the potential to provide solutions for fighting food deserts and ultimately the big picture of world hunger. iv Table of Contents Page List of Figures vii List of Tables xi Acknowledgements xii Chapter 1 Literature Review 1 1.1 Current Global Food Statistics and Future Predictions 1 1.2 Vertical Farming 4 1.3 Controlled Environment Agriculture (CEA) 6 1.4 Innovative Growing Systems and Current Use of CEA 7 1.5 CEA through LED utilization 9 1.6 Realizations of CEA and Energy Consumption 11 1.7 Microgreen and Organic Food Trends 13 1.8 Urban Agriculture and Urban Farming 15 1.9 Urban Agriculture Implementation 16 1.10 Realizations of Urban Farming 17 1.11 Benefits of Urban Farming 19 1.12 CEA and Urban Farming 19 1.13 Review and Preface 20 1.14 GreenTowers 21 1.15 Aquaponics 22 Chapter 2 Rotating Living Wall 28 2.1 Introduction 28 2.2 Materials and Methods 28 2.2.1 System Design and Construction 28 2.2.2 Production Experiments Methods 33 2.2.3 Experimental Setup and Layout 37 2.2.4 Process 40 2.2.5 Performance Criteria 43 2.2.6 Light Analysis Methods 44 2.2.7 Financial Analysis Methods 46 2.3 Results and Discussion 49 2.3.1 Production Experiments Results 49 2.3.2 Light Analysis Results 59 2.3.3 Financial Analysis Results 62 Chapter 3 Living Furniture 68 v 3.1 Introduction 68 3.2 Materials and Methods 68 3.3 Results and Discussion 80 3.4 Financial Analysis 81 3.5 Discussion 82 Chapter 4 Conclusions and Future Direction 83 4.1 Conclusions for Rotating Living Wall 83 4.2 Future Direction and Research 84 4.2.1 Passively Rotating Living Wall Integration 84 with Commercial Aquaponics Systems 4.2.2 Research for the Future 89 4.3 Conclusions for Living Furniture 90 4.4 Future Direction and Research for Living Furniture 90 4.5 Future Predictions 92 References 93 Appendix A Statistical Outputs Rotating Living Walls 98 Appendix B Statistical Outputs Living Furniture 104 Appendix C Light Analysis Data 109 vi List of Figures Page Figure 1.1-1. USDA Economic Research Service Food Access Research Atlas (US) 2 Figure 1.1-2. USDA Economic Research Service Food Access Research Atlas 2 (NY, PA, MD, DC) Figure 1.1-3. USDA Economic Research Service Food Access Research Atlas 3 (NY-Philadelphia) Figure 1.1-4. US Households By Food Security Status, 2013 3 Figure 1.7-1. USDA Economic Research Service U.S. Organic Food Sales (2012) 14 Figure 1.7-2. USDA Economic Research Service U.S. Certified Organic Cropland (2012) 14 Figure 2.2.1-1. Overall System Layout 28 Figure 2.2.1-2. Friction Drive 29 Figure 2.2.1-3. Gutter Trough J Bolt 29 Figure 2.2.1-4. Gutter Troughs 29 Figure 2.2.1-5. C.A.P. ART-DNE Digital Adjustable Recycling Timer 30 Figure 2.2.1-6. Framing 30 Figure 2.2.1-7. 3D SketchUp Model (Front View) 31 Figure 2.2.1-8. 3D SketchUp Model (Side View) 31 Figure 2.2.1-9. 3D SketchUp Model (Trough Detail) 32 Figure 2.2.1-10. 3D SketchUp Model (Alternative Frame) 32 Figure 2.2.2-1. 12 Varieties of Microgreens 34 Figure 2.2.2-2. Oscillating Linear Actuator Bench 36 Figure 2.2.3-1. Greenhouse Setup 37 vii Figure 2.2.3-2. SketchUp Model of Experimental SetUp 37 Figure 2.2.3-3. General Experimental Layout 38 Figure 2.2.3-4. Experimental Setup in Greenhouse (Summer) 38 Figure 2.2.3-5. Experimental Setup in Greenhouse (Fall) 39 Figure 2.2.3-6. Experimental Setup in Greenhouse (Winter) 39 Figure 2.2.3-7. Experimental Setup in Greenhouse (Spring) 40 Figure 2.2.4-1. Vacuum Seeder Manifold 41 Figure 2.2.4-2. Shop Vacuum 41 Figure 2.2.4-3. Seeding Template 41 Figure 2.2.4-4. Jig and Hopper 42 Figure 2.2.4-5. Hedge Trimmer 42 Figure 2.2.4-6. Harvested Product 43 Figure 2.2.5-1. SPAD Meter 43 Figure 2.2.7-1. Two Fluorescent Light Fixtures 46 Figure 2.2.7-2. Metal Halide Light Fixture 47 Figure 2.2.7-3. LED Light Fixture 47 Figure 2.2.7-4. Light Meter 48 Figure 2.2.7-5.