Do you think that we could grow plants without soil? Yes, we can certainly grow plants in that manner. But how? Curious, isn’t it? The new precision agricultural techniques are used for this purpose. Light, air, water and nutrients are the four main things that plants need to be alive. Soil acts as the substrate for plants to anchor to the ground and provides nutrients and water. Plants don’t need soil if the nutrients and water required for plants can be obtained in any other way instead of the soil. This is the key point that is used in ‘Hydroponics’, ‘aquaponics’, ‘aeroponics’ cultivation techniques.
Hydroponic cultivation is a technology used for growing plants in nutrient solutions. “Hydroponics” is a word derived from Greek to reflect the importance of ‘Hydros’(water) and ‘Ponos’(working). Hoagland and Albert Solutions are the main nutrient solutions used in Sri Lanka for this cultivation. These solutions contain water and fertilizer. It is essential to dip the plant roots in the solution. Sand, Coir, gravel, vermiculite, peat moss, sawdust, etc. are used to provide mechanical support to plants. Solutions should be aerated since plants uptake oxygen from roots. This cultivation technique is mostly done in greenhouses because air and root temperatures, light, water, and plant nutrition should be maintained. Tomatoes, cucumbers, lettuce, eggplant, peppers, melons, strawberries, and herbs such as basil are mostly cultivated plants in hydroponic systems.

The aquaponic system is a way of growing fish and crops together in a completely closed-loop ecosystem. Fish excretes urine and fecal matter into the water. Those waste materials are rich in ammonia. But the accumulation of these waste materials in the water can be toxic to plants and fish. Therefore, waste is pumped into a separate tank where microbes (nitrifying bacteria) break fish waste into nutrients which can be considered as a nitrogen-rich fertilizer for plants. Then, the nutrient-rich water is pumped to another tank where plants grow like in hydroponics systems. Plants uptake the nutrients through their roots. Clean water is pumped back into the fish tank and the process continues.

Aeroponic cultivation is the process of growing plants in the air or a mist environment consisting of a complete nutrient solution. In this technique, plants are allowed to find the best condition in terms of oxygenation and moisture. Moreover, plants can absorb the maximum amount of nutrients under low-stress conditions. Therefore, plants are healthier overall and have better colour, texture, and taste. This can lead to having greater plant productivity than hydroponic and aquaponic cultivations.

The number of people in the world is increasing drastically while the number of arable lands is decreasing. Traditional farming is not enough to feed that amount of population. Therefore, above mentioned agricultural techniques are essential for tomorrow. Not only that, but people also ask for pesticide and insecticide-free crop cultivations and search for food produced in an environmentally healthy manner with good quality. We can use these hydroponic, aquaponic and aeroponic techniques to solve all those problems. We should encourage all plant growers who like to incorporate modern technology into agriculture. Beginning with a small step will direct to a huge milestone!

Image courtesy:
Featured image:
https://miro.medium.com/max/1600/0*5pd3QRi-2ztJoQY1.jpg
Figure 1:
https://www.maximumyield.com/images/uploads/maximum-yield-flushing-hydroponics-garden.jpg?height=580&width=940&mode=crop
Figure 2:
https://714493.smushcdn.com/1156533/wp-content/uploads/2020/07/Aquoponics_1200x675-1024×576.jpg?lossy=1&strip=1&webp=1
Figure 3:
https://cdn.greencamp.com/wp-content/uploads/2017/09/aeroponics-illustration-02.jpg
References –
http://chesci.com/wp-content/uploads/2017/01/V6i22_30_CS072048042_Irene_838-849.pdf