Key Types of Hydroponic Systems and Their Applications
Plants transform light energy to chemical energy by the process of Photosynthesis. They need light, water, CO2, and certain minerals. Plants absorb water and essential nutrients for the growth of the plants 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.
The word “Hydroponics” came up from the word “hydros'' which means water and “ponos” meaning toil or labour. It is an agricultural 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, and 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 time to time 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 with 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 drains on top of plants. By using this method, small plants tend to have less developed root systems.
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. In the form of mists, the mineral solution is sprayed to the plants 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 is the best method that can be used to grow food away from earth where there is unavailability of soil.
In Spite of All the Benefits, There Are a Few Drawbacks of Using Hydroponics
High upfront investment
Requires technical knowledge
It can also be misused to grow marijuana that comes under banned products
FAQs on Hydroponic Systems Explained: Benefits & Working
1. What is hydroponics and what is its basic working principle?
Hydroponics is a method of growing plants without soil. Its working principle is to provide all the essential nutrients that plants would normally get from the soil directly to their roots through a water-based nutrient solution. Plants are typically held in an inert growing medium like perlite or rockwool for support, while their roots are bathed in this solution, which also needs to be well-aerated to provide oxygen.
2. What are the main types of hydroponic systems used for cultivation?
There are six primary types of hydroponic systems, each differing in how it delivers the nutrient solution to the plant roots:
- Wick System: A simple system where a nylon wick draws nutrient solution from a reservoir up to the growing medium.
- Deep Water Culture (DWC): Plant roots are suspended directly in an oxygenated nutrient solution.
- Nutrient Film Technique (NFT): A continuous, thin film of nutrient solution flows over the ends of the plant roots.
- Ebb and Flow (Flood and Drain): The growing medium is periodically flooded with the nutrient solution and then drained back into the reservoir.
- Drip System: Nutrient solution is dripped onto the base of each plant using emitters.
- Aeroponics: Plant roots are suspended in the air and misted with the nutrient solution at regular intervals.
3. What are the most significant advantages of hydroponics over traditional soil-based farming?
Hydroponics offers several key advantages over traditional agriculture. Firstly, it allows for a much higher crop yield in a smaller space. Secondly, it conserves a large amount of water, often using up to 90% less than soil farming. Other major benefits include faster plant growth, elimination of soil-borne pests and diseases, and the ability to grow food in any location, regardless of soil quality or climate.
4. What are the main challenges or disadvantages of setting up a hydroponic system?
While beneficial, hydroponics has its challenges. The primary disadvantage is the high initial setup cost for equipment like pumps, timers, and containers. It also requires a good understanding of plant science and system management. Since many systems rely on electricity, they are vulnerable to power outages, which can harm or kill the plants. Finally, if a water-borne disease infects the system, it can spread very quickly to all the plants.
5. How is hydroponics used in scientific research to identify essential plant nutrients, as per the CBSE syllabus?
Hydroponics is a crucial tool for plant scientists. It allows them to create a perfectly controlled environment to study plant nutrition. By growing a plant in a nutrient solution where a specific element is deliberately omitted, researchers can observe the resulting deficiency symptoms. This process helps them determine precisely which mineral elements are essential for a plant's survival and growth, distinguishing between macronutrients and micronutrients.
6. Why is aeration of the nutrient solution so critical for plant health in hydroponics?
Plant roots require oxygen for cellular respiration, a process that releases energy needed for nutrient and water uptake. In soil, roots find oxygen in air pockets between soil particles. In a hydroponic system, since the roots are submerged in water, oxygen is limited. Therefore, aeration (using an air pump and air stone) is critical to dissolve sufficient oxygen in the water. Without adequate oxygen, roots can effectively 'drown', leading to root rot and plant death.
7. What are the key components of the nutrient solution in a hydroponic setup?
The nutrient solution is far more than just water; it is the complete diet for the plant. It must contain all the essential elements for plant growth in a dissolved, ionic form. These are broadly categorised as:
- Macronutrients: Needed in larger quantities, such as Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), and Sulphur (S).
- Micronutrients: Needed in smaller amounts, including Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Boron (B), and Molybdenum (Mo).
8. Can all types of plants be grown hydroponically? What are some common examples?
While the technique is versatile, not all plants are practical for hydroponics. It is best suited for plants with smaller root systems and relatively fast growth cycles. Excellent examples include leafy greens like lettuce and spinach, herbs like basil and mint, and vining crops such as tomatoes, cucumbers, and peppers. Large root vegetables like potatoes and carrots, as well as large shrubs and trees, are generally not suitable for typical hydroponic systems due to their size and growth requirements.
