Knowledge Sharing

Why Hydroponic is Required ? 

Happy family Everyone is aspiring for a happy family. There are three enablers to achieve happy family. These enablers are financial security, health security and social security. Every human being is busy in achieving financial and social security in their own way. But the health security could be achieved by following : 

Healthy Life style 

Regular Physical Exercise 

Regular Breathing Exercise 

Creating Healthy Environment 

Consuming Healthy Food 

First three could be achieved by doing individual efforts, but last two could be better achieved by collaborative approach. With Covid pandemic, breathing exercise become integral part of our daily life. Pre-Covid, we all were struggling with the air pollution. So, healthy environment and nutritive food are the major enabler for ensuring healthy life. Healthy environment and healthy food could be ensured by “khetibadi” especially by hi-tech khetibadi like Hydroponics, Aquaponics or Aeroponics.

Our ancestors started their life as hunter and gatherer moved to shifting cultivation when they learnt farming. They further advanced to subsistence farming and adopted the barter system. With the increasing food demand, we were forced to adopt commercial farming. We experienced the green revolution during this phase and achieved food self-sufficiency and become net food exporter. These benefits were coupled with some serious drawbacks like natural resource deterioration, agriculture produce quality deterioration, etc. The problem aggravated when as a consumer we don't have any tool to asses the quality of agriculture produces. 

The Covid pandemic disrupted the logistics of the agri-value chain. This led to adoption of hydroponics by the consumers themselves and the area under urban and peri-urban hydroponic started expanding. The consumers were become producers and were able to produce nutritive food for their own consumption. As there were resource constraint faced by the producers in peri urban and urban hydroponic, it limited the growth of area under hydroponic growing systems. 12 With the development of perry urban and urban hydroponic growing systems, the agriculture sector has developed in to two distinct segments. One is the existing traditional farming and other is urban farming. The traditional farming is distinctly supplying the food grains whereas hydroponics/urban farming provides the greens and therefor they are not competitors. As the urban farming is an additional producing agri-produce system, it requires due attention for removing the constraints like technology, resources and skill development. This will lead to expansion of urban farming like hydroponics in the next 10-20 years. 

A world bank estimate indicates that by 2050 globally there will be additional 30 billion population of which around 80% is going to settle in urban areas. The significance of hydroponic growing systems will assume a greater role. 

The peri-urban and urban farming is now developing in to two different segments, commercial vegetable growing and hi-tech vegetable growing like hydroponics/aeroponics/aquaponics. The commercial vegetable farming is growing because of the producer to ripe more profit irrespective of the produce quality. The commercial peri-urban and urban vegetable growing is mostly practiced on marginal lands and using urban manure and sewage water. Where growers use fertilizers and pesticides they are ignorant of good farming practices. The produce quality has therefore suffered because of the load of pesticide residues, heavy metals and the nitrate load. 

Looking in to the interest of consumers from the produced quality, the dependence on hi-tech growing systems like hydroponics/aquaponics/aeroponics is called for. 

What is Hydroponics? 

Word hydroponics comes from the Latin language and it means “working with water”. “Hydro” means water and “ponos” means labor. The most popular definition of hydroponics is “growing crops without soil”. But this definition does not give any information whether the technology is related to the crop root or crop leaf or crop shoot. In hydroponic growing system, most of the modifications are confined to the crop root zone. In NFT and DWC hydroponic growing system the roots are absorbing nutrient solution from the running water in grow chambers. Whereas in soilless hydroponics, the root absorbs nutrients from the water stored in the tiny pores of growing media. This indicates that the hydroponic growing technique is related to modifying the growing condition around the root zone. This technique does not have any direct interference in shoot part of any crop. Roots are the mouth of plant. They absorb the required raw material and shoots help in translocating the absorbed raw material to the location of food synthesis. Healthy mouth i.e. roots ensure better crop growth and development and ultimately help in ensuring better quality and productivity of any crop. 

An efficient grower in hydroponic growing system is having option to control all the factors for ensuring ideal micro-climate around the rootzone. They can calibrate the hydroponic growing system as per the requirement of crop and climatic conditions. This crop growing technique provides 100% control in the hand of growers. This technique eliminates any possibility of plants eating any junk foods like heavy metals, imbalance fertilizer, harmful micro-organisms etc. and it ensures quality agricultural produce. The technical definition of hydroponic growing system is "enabling the growers to create ideal micro-climate around the rootzone". 

Types of Hydroponics 

There are different types of hydroponic growing systems. These hydroponic systems could be classified based on the following criteria : 

1. Growing conditions; 

2. Nutrient circulation; 

3. Light used. 

As per the crop growing conditions, hydroponic system is divided into three different segments. These segments are: 

i. Soilless Hydroponics 

ii. Nutrient Film Technique (NFT) Hydroponics 

iii. Deep Water Culture (DWC) Hydroponics 

The crops grown with growing media are called soilless hydroponic growing systems. In this system any inert growing medium is used to grow crops. Any material fulfilling the following requirements is considered to be a good growing medium for hydroponic growing system: 

I. Inert in nature i.e. zero potential of crop nutrient supply, 

ii. having the ability to hold moisture, 

iii hard to digest/disintegrate. 

Cocopeat, perlite, rockwool and vermiculite are the most commonly used growing media. In this system drip irrigation system is used to deliver nutrient solution to the crops. 

Nutrient Film Techniques (NFT) is one of the most commonly used hydroponic growing system. In this system NFT grow channels are used to grow plants. In this system no growing media is used. The plants only grow in nutrient solution. A thin layer of nutrient solution runs in grow-channels and the plant root absorbs nutrients from the flowing nutrient solution. These NFT grow channels are available in different designs and shapes. Flat bottom grow channels are always a preferred choice for any commercial hydroponic projects over circular pipes. In flat bottom channels the root spared across the flat surface. This helps in increasing the surface area of root contact with the flowing nutrient solution. The surface area of root contact with nutrient solution is always higher in flat bottom as compared to circular pipes. This happens because in circular pipes roots always try to confined on the lowest point of the pipe, which reduces the root area of contact with the flowing nutrient solution. 

Deep Water Culture (DWC) system is a modified version of NFT hydroponic. In this system, the thickness of the water layer ranges from 12-15 inches. In this system the crop is also grown without growing media. Plant roots are always suspended in the moving water and the root absorbs nutrients from the solution. 

Controlling algae growth is one of the most critical challenges in this system. Rapid algae growth is the outcome of direct exposure to sun and abundance of moisture. Algae growth in the system leads to higher requirement of dissolved oxygen. This becomes a cause of competition for dissolved oxygen between algae and plant roots, which is not good for proper plant growth. Though in DWC hydroponics the impact of high climatic temperature is limited on root development, despite this benefit, NFT hydroponics is a preferred hydroponic system in the hot, humid and sunny regions. 

As per the nutrient circulation, soilless hydroponics system is classified in to two sub categories i.e. open and close system. Close nutrient circulation system is a system where the excess leached water recirculates in the system. This is an efficient system over the open nutrient circulation system where the excess leached water runs for the waste. NFT and DWC system is a close circulating system, where the nutrient solution continuously circulates in grow-channels. 

Light is a source of energy for plant growth and development. Based on the type of light used, hydroponic growing system is classified into two sub categories i.e. natural light and artificial light. As per the project requirements, hydroponic growing systems are either installed in natural light or in artificial light. 

How to identify ideal hydroponic growing system for Different Crops – The plant root system depends on the morphological characters of any plant. Depending on the root systems, different crops prefer different hydroponic growing systems. In most of the long duration vine crops' the total root mass is higher as compare to short duration leafy crops. Higher root mass is an indicator for higher rate of root respiration which requires higher amount of dissolved oxygen around the root zone. Soilless hydroponic growing media holds a higher amount of dissolved oxygen content and because of that this is the preferred hydroponic growing system for long duration crops like cucumber, tomato, capsicum etc. This does not mean that the leafy crops cannot be grown in soilless hydroponic growing system. There are references indicating a successful production of short duration leafy vegetables in soilless hydroponics, especially in hot and humid climatic areas. But there are limited references available where the vine crops are successfully grown in NFT or DWC hydroponic growing system. 

Most of the leafy crops are short duration crops like leafy crop i.e. lettuce, rocket, spinach. The root mass of these crops is less as compared to the long duration vine crops. Less root mass helps these crops to perform better in the growing medium where the level of dissolved oxygen content is lower. Hence NFT and DWC hydroponic growing systems are the best growing systems for these crops. 

The selection of NFT vs DWC depends on the prevailing climatic condition. NFT growing system is a good system for the areas with uniform temperature, but DWC growing system performs better in the area where the temperature variation is quite high. The higher volume of running water in DWC takes longer time in increasing and decreasing the temperature of water around the root zone, which helps in maintaining uniform temperature around the root zone. Despite these benefits, NFT is becoming popular in areas with temperature extremes. This popularity of NFT system is because of the challenge of algae growth in DWC growing system. 

Due to these challenges the growers are choosing NFT hydroponic growing system in extreme temperature areas too. But to get the benefit of DWC hydroponic system they are adding water cooling system and keeping the water temperature as per the crop requirement. Inclusion of water-cooling system helps in increasing the volume of dissolved oxygen in water. It is an established fact that the water temperature inversely proportion to the dissolved oxygen content in water. 

So, identification of the right hydroponic growing system enables the growers to minimize the risk of crop failure. One of the options, to mitigate this risk, is bridging the existing knowledge gap to ensure selection of the right growing system. 

Crop grown in Hydroponic growing system 

Different crops are grown in hydroponic growing systems, these crops are categorized into different categories. These categories are: 

Established crops 

These crops have been grown in Hydroponic growing system for the past few decades. The growing techniques of these crops are quite established in hydroponics. Most of these crops are grown in the developed countries, but past decade Indian hydroponic growers are growing these crops in India too. These crops are: 

Vine crops like Cucumber, Tomato, Capsicum etc. 

Leafy vegetable crops like Lettuce, Basil, Kale, Arugula, Rocket, Spinach etc. 

Flowers like Rose, Gerbera, Lilium etc. 

Trial crops 

These are the crops which are being tested in hydroponic growing system and showing better result in different hydroponic growing systems. These crops are: 

Essential oil-bearing crops like damask rose, jasmine, saffron etc. 

Medicinal crops 

Herbs 

Fruit crops 

Potential Crops 

The crops having high market value are the potential crops. These crops need to be tested in Hydroponic growing system and develop a crop production protocol. 

As the hydroponic is a technique to create better micro-climate around the root zoon, “any crops can be grown in hydroponic growing system” be an orchard crops like mango, guava etc. The only requirement is to establish the crop production protocol before growing any crop in commercial hydroponic growing system.