Introduction

1. Introduction

1.1 Engineering Problem

The world’s population is increasing very rapidly and the supply for food is not going to be able to meet demand soon. (Collins, 2013) An answer to this is to increase the rate of agriculture. However, this poses another set of problems. Lots of land will be required and the space will not be maximized to full potential. An answer to this is ways of farming. This project aims to make use of technology to make space efficient agriculture techniques.

1.2 Engineering Goals

To build a single-layer and sustainable aeroponics farm that can operate in space restricted urban areas.

1.3 Specific Requirements

- Low-energy consumption

- Must be space saving

- Cost effective

- Time saving

- Easily manageable

1.4 Alternative Solutions

1.4.1 Aeroponics

Aeroponics is the process of growing plants in an air or mist environment without the use of soil. Aeroponics is a relatively new way of growing plants that is getting increasingly popular with many people because of the speed, cost and novelty. (Garderner, 2008)

Unlike hydroponics, which uses a liquid nutrient solution as a growing medium and essential minerals to sustain plant growth; or aquaponics which using water and fish waste, aeroponics is conducted without a growing medium. (Garderner, 2008)

Plants grown using aeroponics spend 99.98% of their time in air and 0.02% in direct contact with hydro-atomized nutrient solution. (Garderner, 2008) The time spent without water allows the roots to capture oxygen more efficiently. (Clark, 2008)

Aeroponics allows more control of the environment around the root zone, as, unlike other plant growth systems, the plant roots are not constantly surrounded by some medium. (Clark, 2008)

A typical aeroponics system is made up of high pressure pumps, sprinklers and timers. If any of these break down, your plants can be damaged or killed easily. (Garderner, 2008)

Most aeroponic systems are not exactly cheap. Aeroponic systems may cost many hundreds of dollars each and they use lots of energy to operate.

1.4.2 Hydroponics

Hydroponics is a subset of hydroculture and is a method of growing plants using mineral nutrient solutions, in water, without soil. (Wikipedia, 2013) Terrestrial plants may be grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, gravel, mineral wool, expanded clay pebbles or coconut husk. (Wikipedia, 2013)

No soil is needed for hydroponics. The plants are grown in other mediums. The water stays in the system and can be reused. Thus, there is a lower water requirement. It is also possible to control the nutrition levels in their entirety, which results in lower nutrition requirements. (Patterson, 2013) No nutrition pollution is released into the environment because of the controlled system. (Patterson, 2013) There are stable and high yields and pests and diseases are easier to get rid of than in soil because of the container's mobility. (Patterson, 2013) The plants grow healthier because there is no pesticide damage. It is also easier to harvest, and better for consumption.

Without soil as a buffer, any failure to the hydroponic system leads to rapid plant death. Other disadvantages include pathogen attacks such as damp-off due to verticillium wilt caused by the high moisture levels associated with hydroponics and over watering of soil based plants. (Wikipedia, 2013) Also, many hydroponic plants require different fertilizers and containment systems.

1.4.3 Dynaponics

Dynaponics is an improvement from aeroponics to make it more energy and water efficient while maintaining the air environment for the plants to grow in. (Kevin, 2013) This is done by having air pumped through a reservoir under the roots of plants that are suspended in mid-air, shooting water drops at the plant roots providing the plants with the nutrients and water that they need. (Kevin, 2013)

The use of Dynaponics will reduce the amount of water used and the area needing while increasing the rate at which the plants will grow dynaponics systems are also much more energy-efficient than aeroponics systems. (Kevin, 2013)

Like Aeroponics, the roots are suspended in mid-air and the roots are oxygenated, resulting in healthier crops and better produce. (Kevin, 2013)

Dynaponics, while they are energy and water efficient, and able to grow plants much quicker and space saving, were not designed for commercial farming. (Kevin, 2013) These systems might not be able to deliver the water fast enough due to the air jets being of low pressure, and the crops may wilt and die. (Kevin, 2013)

1.4.4 Final Solution

Our final solution is Aeroponics.

Why did we choose it over other solutions?

Aeroponics allows plants to have an easier intake of oxygen due to exposed roots. It is also easier to manipulate the environment of the plants due to the lack of need for a medium for the roots.

While Aeroponics may be generally known to use a lot of energy and be expensive, we can overcome these problems by using a low-cost solar panel to provide energy to the set-up. We are also using cheap but effective materials such as foam boards, PVC pipes, and relatively low pressure pumps.

The disadvantage of other solutions outweigh their advantages, as Dynaponics is not practical for large-scale use, and is mostly used in small-scale experiments or as demonstrations, as it is a relatively new concept.

As for Hydroponics, the plants will be less healthy than those grown in an Aeroponics set-up, due to the roots not being able to take in much oxygen.

The Final Design

We chose this project because our country is facing restricted land space and almost all of our food is imported. We hope to be self-sustaining in terms of food.