Use of Hydroponics as a Method to Study Mineral Nutrition

Introduction

Soil is an integral source of nutrition for growing plants. Apart from plant growth, soil also assists plants in retaining water and protecting themselves against erosion. It can even be said that we are very accustomed to the image of plants growing in soil. 

However, there exists a technique of growing plants that do not use soil at all. This technique is known as hydroponics. The elementary idea of hydroponics is used as a method to study mineral nutrition. The term hydroponics has been derived from the Greek words “hydros” and “ponos” and roughly translates to “water working”.

Hydroponics

Hydroponics refers to the process of growing plants using water instead of soil. It can be considered a subtype of hydroculture, a science that uses capillary action to distribute water and nutrients in the plant.  

In this technique, plants receive nutrition through water-based solutions containing the minerals that the plant requires. These nutrients can be synthesised in the lab or obtained from compost material such as fish waste and duck manure. 

Popular examples of hydroponic produce are peas, onions, artichokes, cucumbers, leeks, radish, etc. This technique can benefit commercial farmers that need to grow high yields of specific crops. Additionally, this technique is also beneficial in cities with less space where residents wish to cultivate fresh plants in their surroundings. 

How does hydroponics work? 

Hydroponics works by delivering nutrients to the plant through a growing medium with a well-balanced ph level in a soluble solution form. This allows plants to carry their food without much exertion. This is in contrast with the energy exerted to obtain nutrients from the soil. Therefore, by delivering the exact quantity of nutrients required by the plant with ease, the hydroponics technique makes the plant grow up to its potential.

A growing medium is a substance from which the roots of a plant emerge. The nutrient solutions for the plant are delivered through the growing medium. The hydroponics technique can use several different growing mediums. They can be gravel, sand, coconut fibre, vermiculite, rock wool and other organic materials. 

Different kinds of hydroponics delivery system

The growing medium used for hydroponics requires a delivery mechanism to deliver the nutrient source. The following are delivery mechanisms:

1. Wick System: This technique uses the wick’s capillary motion to transport nutrients from a reservoir to plant roots.
2. Ebb and Flow System: This system is also known as the flood and drain system. It is frequently automated through a pump and timer. In this system, the growing medium or tray is filled with the nutrient solution and then subsequently drained.  
3. Drip Recovery System: in this system, a tube is used to pump nutrient solution through drip lines dropped into the roots of the plant. 
4. Water Culture System: In this system, plants stored in net pots are put on a floating vessel on top of containers of water filled with nutrients. The hovering roots are spread out into oxygenated solutions rich with nutrients. This is done to facilitate growth and development.  

Apart from these systems, other popular types of hydroponics systems include the aeroponic system and the nutrient film technique.

1. The Nutrient Film Technique (NFT) is frequently used to cultivate small, fast-growing plants such as lettuce. It’s a well-known hydroponic system with components similar to Ebb and Flow. They both use water pumps to supply nutrients to the plants but the NFT system, in contrast to the flood and drain dynamics of an Ebb and Flow configuration, is continually flowing.
2. Aeroponics is a way of cultivating plants that does not require the use of soil. Roots are hung in the air and irrigated with a nutrient-rich mist. It  provides better oxygen access to the roots, resulting in stronger plant root mass, higher crop growth rates, and enhanced yield.

Hydroponics as a method to study plant mineral requirement 

Soil is the traditional medium for the mineral nutrition of the plant. But since soil contains a mix of nutrients, it may be difficult to determine what the plant in what measure requires nutrients and minerals. 

To solve this question, in the mid 19th century, Julius von Sachs, a German Botanist, came up with a method to evaluate the mineral requirements of plants. This technique is now known as hydroponics. The technique analyses plants grown in a specific nutrient solution. 

Over time, researchers studied the plant’s reaction to nutrient solutions containing different proportions, mixtures, and variations of nutrients. Based on these observations, there now exists a database of information about the essential elements required for plant growth. The technique can also evaluate what elements are deficient in the plant based on deficiency symptoms.  

This wealth of knowledge makes hydroponics a very commercially viable as well as a sustainable practice.

Advantage of the hydroponics technique

The following are advantages of hydroponics that make the technique accessible, feasible, and efficient: 

• An optimum level of nutrition 
• The plants are healthier and mature faster
• Increase in yield
• No use of fertilisers or other harmful chemical
• Allows for controlled plant growth with control of the nutrition 
• Plants are less susceptible to diseases and pests
• Leads to the conservation of water as the water can be reused 
• Ease in eliminating weeds due to lack of soil
• Possibility of introducing automation in the process
• Decreases loss of nutrients 

Disadvantages of hydroponics techniques

The following are prevalent issues concerning hydroponics: 

• A high initial cost of investment
• The need for technological know-how and expertise
• The water-based system is susceptible to waterborne infections
• The method is time-consuming and may divert time from other farming activities
•  Only certain soluble nutrients can be used in the process

Considerations while using hydroponics for farming

While most crops can be grown using hydroponics, certain vegetables specifically grow much better in hydroponics systems. These include moisture-resistant crops such as capsicum, tomato, lettuce, strawberries, and other leafy vegetables. Another important consideration while establishing hydroponic farms is the delivery system going to be used. This choice must be made based on the type of crop as well as climate. 

Conclusion

Hydroponics is a new technique used in farming that uses water-based mineral solutions and nutrition sources instead of soil. The process has immense benefits and thus is a commercially viable environment-friendly farming practice. The hydroponics technique can thus be considered the future of farming in a world with changing climates and degrading soil quality. The fact that hydroponics can increase crop yield can also prove to be the solution to eradicating world hunger. Lastly, hydroponics can also help in further nutrition studies of new emerging plant species. Thus this technique has both commercial and research applicability.