1. Introduction

Introduction

1.1 Engineering Solution



With the growing population the world as a whole is facing, we would of course need more food, as

we would have more and more mouths to feed. It may not seem like a problem now, but it will be in 5

to 10 years, and it's only a matter of time before we run out of space to grow food. Our capacity to

hold people in this same planet we share might be close to infinite, but space for agricultural means is

not. (Erin, R.2014, 01 29).This is gradually becoming a massive problem and if we do not solve it now.


1.1 Engineering Problem


Our solution is to turn to Urban farming as a way to relieve some of the food shortages on an

international scale. Why go through the process of cooling, freezing and shipping tonnes of food when

you can grow it just at your neighbourhood? (Jane, B. 2014, January 22)This way of agriculture

ensures quality, value for money and can lower the cost of vegetables and other food, thus helping the

lower to middle income families to afford groceries and lessen their burden. Urban farming is definitely

the way to go, if we want to solve this problem efficiently.

Specify Requirements

In particular, our team wanted to

1)   Control the amount of water used to water the plant without giving too much or little

2)   Control the amount of light in the box ensuring the plant growing efficiently

3)   Maximise the amount of crops being able to be planted in a design

1.4 Alternative solutions


1.4.1  Aquaponics


Aquaponics is a sustainable food production system that consists of conventional aquaculture of breeding aquatic animals and hydroponics, which is a water-based method of cultivating plants. Effluents which are gases and slightly polluted water from the waste of the aquatic animals will accumulate in the water, and increase the toxicity level for the fish. As such, these by-products will be broken down by nitrogen-fixing bacteria, then filtered out by the hydroponics plants.

The advantage is that this system is self-sustainable, and it is an environmentally-friendly method for the hydroponics, which usually uses chemical-based solution for breeding. As the water is constantly being recirculated, water usage is minimal and reuse of water is highly efficient (McCarthy, 2013).


Unfortunately, a major disadvantage would be that it is usually expensive to set up, inclusive of the cost for the tank, tubes and pumps. Water pH level will also have to be monitored closely, as one faulty component can cause the whole system to break down easily. It is also not advised to grow root crops. Leafy vegetables are advised instead. The water needs to be free of toxins such as ammonia and nitrates and have sufficient oxygen levels for aquatic organisms to survive. This would create a complex system that may break down easily (McCarthy, 2013).


1.4.2 Hydroponics


Hydroponics is a method of crop cultivation which uses the method of soilless growth of plants. The nutrients that are normally found in soil are dissolved into water, creating nutrient solutions.  Roots are usually submerged or suspended to be able to absorb the nutrients found in the solution. Since arable land is on the decline, hydroponics is seen as a solution where plants can be cultivated using water which is abundant, hence it is versatile (Turner, 2008).


Hydroponics has several advantages. It has almost no pollution as most of the nutrients are all absorbed by the plants. Normally, agricultural runoff contains fertiliser, containing high amounts of nitrogen and phosphorous. If leaked into water bodies, algae would bloom uncontrollably and use up oxygen rapidly. This would cause the death of aquatic organisms. Hydroponics do not require any herbicides or pesticides, as they are usually grown indoors. Less labour is involved in the up-keeping of such a garden as only the nutrient solutions need to be in check. The growth rates are spruced up as compared to normal soil cultivation, due to the availability of water, oxygen and easily accessed nutrients (Hydroponic Setup, 2010). The water can also be recycled, hence there would be lower water costs.


However, everything has its advantages and disadvantages. It has a high set-up cost as it requires meticulous planning when designing and constructing (Hydroponics Center, 2011). Hydroponic conditions, especially the presence of high humidity, would create a hot bed for salmonella growth (Department of Agriculture, Forestry and Fisheries, 2011). Salmonella can then be transmitted through human consumption and cause food poisoning. Since hydroponics are soilless, diseases are able to spread quicker as they are not contained (Black, 2009). Hydroponics also require many varieties of fertiliser. Finally, hydroponics are unable to cultivate all plants, hence you are limited to certain species only (The Iloveindia website, 2013).
1.4.3 Aeroponics


Aeroponics is a method where plants are grown in a humid environment without the use of any growing medium, making it suitable for indoor gardening or greenhouses (True Aeroponics™, 2013). It stimulates rapid plant growth as the plants will rapidly develop root systems.

The plants are suspended in a growing chamber. A pulsed sprayer will release a fine, high pressure mist which consists a mixture of water, nutrients and growth hormones into the enclosed environment of the growing chamber at a time interval and duration for the plants (True Aeroponics™, 2013).


Aeroponics, when compared to the traditional method allow plants to grow faster, as the roots are exposed to more oxygen, and thus obtain higher yields from the plants. It has been proven that it can aid growers to optimize rooting on most plants. When root cutting is performed on the plant grown through aeroponics, the plant will maximise its overall yield. Also, the plants in an aeroponics system are fed more than those planted using the traditional method. Aeroponics is beneficial to the environment in a sense that the water used in aeroponics can be reused. The water loss of an aeroponics system is cut by 99% when compared to the traditional farming methods. When compared to hydroponics, aeroponics offers more control over the root system as the roots aren’t immersed in any liquid (True Aeroponics™, 2013).


The Disadvantages of the aeroponics system is that the root chamber, the one containing the dangling roots, attract lots of bacterial growth due to its semi-moist environment, so it has to be cleaned regularly. The entire system depends on the pumps, sprinklers and timers, so if any one of these break down and are not fixed in time, the plants can wither and maybe even die. One must also be proficient in knowledge about plants, such as nutrition amount as there would be no soil to soak up excess nutrition (D’Gardener, 2008). All these may make the system a meticulous one that requires time and effort.

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