Plants transform light energy to chemical energy by the process of Photosynthesis. They need light, water, CO2, and certain minerals. Plants derive water and the nutrients essential for the growth from soil. In 1860, Von Sachs, a German botanist demonstrated that plants can grow without soil if they are provided with a nutrient-rich solution and fulfil their oxygen demand. This technique of growing plants without soil is known as hydroponics. It may sound weird to grow plants without soil but there are many plants like tomatoes that are already being grown hydroponically.
What is Hydroponics?
The word “Hydroponics” is derived from the word “hydros” meaning water and “ponos” meaning toil or labour. It is an agriculture technique where plants are grown in a nutrient solution in the complete absence of soil. Here soil is substituted by sterile mediums such as rockwool, vermiculite, sand, gravel, clay pellets, perlite to give stability to roots. Nutrients are passed through roots differently, based on the type of hydroponic system used and oxygen is pumped through, pH level is regulated and sufficient light is provided to carry out photosynthesis. In the areas where natural light is not available, artificial lighting is provided. It is an innovative method of farming and is being widely used now for food production.
The hydroponic technique is used in determining the deficiency symptoms of various nutrients in plants and to find out essential nutrients for the plant’s growth and development.
Types of Hydroponic Systems
Plants need water, mineral nutrients and oxygen to thrive. There are six hydroponic systems, based on different ways by which these requirements are fulfilled.
- Ebb and Flow System: It requires a medium such as perlite to give stability. Water and mineral solutions are periodically pumped into the tray containing plants. Plants absorb the solution and the remaining solution drains back to the reservoir. This method is simple and used in home gardens. Herbs are grown by this method.
- Nutrient Film Technique (NFT): No medium is required. Plants are kept in wooden channels having a slope. The mineral solution is pumped to the high end of the channel and slope down water is collected and reused. Plants with large roots are grown by this method.
- Drip Systems: It is similar to ebb and flow but here water goes through smaller tubes and drain on top of plants. Small plants having less developed root system is grown using this method.
- Wick Systems: This is a medium based system where perlite or rockwool is used. Nylon rope is placed at the base of each root which extends to the reservoir. It takes up mineral and water and releases in the medium which makes it available for plants. It is an economical method because no pumps are required.
- Aeroponics: This is a water-based system similar to NFT and doesn’t require a medium. The mineral solution is sprayed onto the plants in the form of mist. This is difficult to set up but is beneficial in the large commercial setting.
- Deep Water Culture (DWC): In a container, the plant’s root is suspended in oxygenated water containing minerals. An air pump is used. This is an easy method and requires low maintenance.
Benefits of Hydroponic Systems
Hydroponics has been used since ancient times. Hanging Gardens of Babylon is one such example. There are many benefits of growing plants hydroponically.
- Plants grow faster so the yield is high
- Can be grown anywhere, underground, rooftops and greenhouses
- Plants can be grown where traditional farming is not possible
- Water and nutrients are recycled and reused
- Organic food can be produced without using fertilizers or pesticides
- Hydroponics is extensively used in space research programmes. Hydroponics can be used to grow food away from earth where soil is unavailable
In spite of all the benefits, there are a few drawbacks of using hydroponics:
- High upfront investment
- Requires technical knowledge
- It can be misused to grow banned products like marijuana