Annabelle Tuma 

Professor Weyn 

Writing for Engineers 

Lab Report on Efficiency of Aquaponic vs Soil Systems

 

Introduction

 

                    Our organization aims to build one of the largest urban farming compounds ever created in a city in the United States of America. We hope to grow enough fresh produce annually to help combat certain food desserts in the city of Chicago. Though urban farms are proven to be significantly more environmentally efficient than traditional agriculture, both in immediate water consumption and in associated transportation carbon emissions and fuel usage, this study aims to prove that plants grown in aquaponic systems are also more individually healthy than those grown via traditional soil farming methods. Though soil-grown plants will also be cultivated in a laboratory setting for the purpose of this experiment, we believe our findings will still provide an accurate idea of the farming benefits of an aquaponics system, providing your foundation with a stronger foundational understanding of our vision going forward. 

 

Hypothesis

 

                    We believe that plants grown in an aquaponic system will be healthier than those grown in traditional soil systems. Plant health is here taken to mean number of surviving plants, plants’: leaf size, stem length, leaf number, overall height, and lack of any discoloration, pests or fungus. 

 

Procedure

 

                    We will create a simple “flood and drain” aquaponic system with a 40 gallon fish tank, and ten gallon grow bed. The aquarium will be placed directly underneath the grow bed, with a simple sump pump to drain the grow bed. Another motorized electric pump will be placed on the far edge of the aquarium, and will continuously move a small amount of water into the grow bed. When the water in the grow bed reaches a certain height, it will begin to fill the sump pump, which will then drain back into the fish tank. This design was chosen because of its simplicity and lack of excessive factors that may affect plants and fish health. 

                    The soil system will consist of only a grow bed of equal ten gallons. Grow lights of equal wattage will be placed above both systems at an equal height, and the soil system will receive twice-daily watering of an appropriate amount for any surviving plants’ sizes. If plants are growing unevenly and may require different amounts of water, scientists will use the appropriate amount for the week of growth of the plants, regardless of plant size. The aquaponic system will have an air-tight cover to the fish tank to prevent evaporation, and will have water replenished if the water level in the fish tank directly after sump pump drainage lowers by more than a half-inch. 

                    Twenty sprouted seeds of red kidney bean plants will be placed identically in the grow beds of both systems. They will be planted in five rows of four seeds, equally spaced from each other and the walls of the grow bed. Scientists will observe their growth every day over four weeks. This growth will be observed by number of sprouted plants, surviving plants, leaf number per plant, leaf size, leaf area, stem length, and plant height, as well as any potential buds, plants or seeds, though these would be unlikely given the time limitation of the expirement. Scientists will also make note of any observed discoloration, illness, and infestation, though only if present and not if absent. If plants are observably unwell because of illness or infestation, the plant will be removed from both system and experiment as is the protocol in commercial farms. 

 

Results

 

                    After four weeks of observation, all twenty plants survived in both systems without any notable illness or pest infestation. Of the group of plants in the Aquaponic Systems (Group A), three plant sprouts broke soil before any of those in the Soil System (Group B). Once all twenty sprouts in both systems broke soil, the plants in Group A grew more quickly, with larger and more abundant leaves on average. Five plants in Group B have more leaves of larger area and length than five of the plants in Group A. The other fifteen plants in Group A, however, completely surpassed all those in Group B. 

                    This table shows the growth of the largest plant from both Group A and Group B by collective area of the plants’ leaves. This table shows the initial sprouting of the top plant from Group A’s preceding that of Group B by two days, and the plant’s continued superior size except for a brief tie on day 19, when several days of unusually quick growth by Group B’s plant resulted in an intersection with Group A plant’s steady continued growth. Both plants had a leaf area of 40 square inches on day nineteen, but Plant B’s growth slowed after this while Plant A’s continued to steadily rise, resulting in ending areas of 80 square inches for Plant A, and 65 square inches for Plant B.

 

Conclusion

 

                    In conclusion, our initial hypothesis that aquaponic farming results in healthier plants than traditional soil farming proved correct. Plants grown in an aquaponic system on average sprouted faster, had steadier and more consistent lateral growth, and had more leaves with a larger area. These findings help support the idea that a large urban farm is worth investing in for its superior agricultural yield and more efficient plant growth overall, in addition to aquaponics’ more sustainable water usage and environmentally responsible associated transportation.