With water and soil scarcity, and a large majority of the world’s population moving to urban areas, it is a fact that in the future agricultural production will not be able to keep up with the demand that will exist. According to the UN, to feed 9 billion people in 2050, global food production must increase by more than 70%. However, we have neither the natural resources nor the fertile soils to achieve this goal with current methods. For this reason, alternatives such as aquaponics and hydroponics have emerged in the world of agriculture. Both methods cultivate without soil, and although they have some things in common, they should not be confused.
Broadly speaking, aquaponics and hydroponics share the following characteristics:
- They do not use soil, but rely on water to supply nutrients to the plants.
- Plants grow faster than in soil crops and require less surface area.
- They suffer less pest damage.
- They save large amounts of water.
- It is not necessary to water the plants.
- They make very efficient use of natural resources.
- They do not need fertile soil; they can be practised in any space or on any surface.
That said, what is the difference between hydroponics and aquaponics? Here’s how they work and the pros and cons of each.
Aquaponics: a combination of hydroponics and aquaculture
Aquaponics systems aim to achieve a balance between plants and fish, with the former relying on the latter’s waste for nutrients. It is a more complex technique than hydroponics because it involves fish farming, but the benefits obtained from this practice are worth the effort. Aquaponics uses up to 95% less water than a conventional farm to irrigate vegetable production, due to its process of circulation and reuse of the resource.
Among the disadvantages of aquaponics is the design and construction of the system, which can be a bit more complex than hydroponics. The same applies to management, as in aquaponics we are dealing with an ecosystem, whereas hydroponics involves administering diluted fertilisers to the plants. This means that in aquaponics we will need more knowledge and have the responsibility for the welfare of the fish.
Now, there are several points in which aquaponics is more advantageous than hydroponics. As it is a more complex ecosystem, everything is more balanced. While in hydroponic installations there is more danger of the system losing its fragile equilibrium, in aquaponics the microbiological life present in the system gives stability and increases its ability to cope with changes, thus allowing it to self-regulate.
As an organic process from start to finish – which is another great benefit – aquaponics avoids pesticides and chemical fertilisers, usually artificially synthesised. Its nutrients are found in the fish waste. This means that once the tank is set up, the only product to buy is fish food. On the other hand, pesticides are dangerous for fish and micro-organisms, so healthier and more sustainable pest control methods, such as biological control, must be used.
Finally, it is thanks to the biological origin of the fertiliser that the texture and taste of aquaponic vegetables is achieved, incomparable to hydroponic vegetables, which often lack flavour despite their impeccable appearance.
In short, aquaponics has the great merit of being a circular technology that allows the cultivation of high quality plants and fish, as well as caring for the environment. It may take a little more time to learn this discipline, but it is worth it if you are looking to produce food in the most sustainable way. As a big plus, aquaponics technology also produces protein in the form of fish, so you get animal and plant products in the same process and without the need for additional resources.
Hydroponics: Focusing on plant growth
Hydroponics consists of delivering a nutrient solution dissolved in water to the plants. In this way, the fruits and vegetables receive all the necessary chemicals and minerals, and the use of soil is taken out of the equation.
Hydroponics systems are virtually self-contained to feed the plant, so learning this technique can be simple; you just need to know how to add nutrients properly. Like aquaponics, this technique is ideal for reducing pollution (by producing locally, they reduce the carbon footprint caused by transporting food), which is why both technologies have gained popularity in urban spaces such as rooftops, gardens, terraces, etc.
As mentioned above, the advantage of hydroponics is its simplicity and low cost, although finding the perfect mix of nutrients can be tricky when starting out. In addition to this, although the investment may be high at the beginning, the costs are consistent and predictable. Also the amount of fertiliser used can be estimated within a narrow range. Finally, the size of the system can be as small as a pot.
Now, among the disadvantages of hydroponics, there are some factors to take into account: it requires chemical fertilisers based on fossil fuels and mineral extraction. Therefore, its main disadvantage is the unsustainable origin of the inputs to the process. In addition, a wastewater of concentrated fertilisers has to be periodically disposed of to avoid the accumulation of salts, which is harmful to plants. Algae growth can also be a problem, whereas in an aquaponic installation, fish control algae growth. Finally, the absence of fish and microbiological life means that the system has little ability to balance itself, and that water quality must be controlled much more precisely.
In conclusion, both hydroponics and aquaponics follow similar purposes, but their working methods are different. If the farmer is looking for simplicity and lower investment, hydroponics will be an interesting option. On the other hand, for a farmer looking for maximum sustainability and product quality, aquaponics will be the more attractive option.
For people looking to install a system at home, you will need to look at the space available and choose the process that best suits your needs. It is important to stress that the upfront and running costs will be forgotten when the fresh vegetables are in your home and not in the supermarket! Furthermore, once you consider the money spent on supermarket food, it is easy to conclude that an aquaponic system can pay for itself within a few years.
Remember that if you are looking to learn about aquaponics or to buy food grown with this technology or even an aquaponic system, you can do so through Green in Blue.
