“Agriculture is the definitive evolutionary step that raised man to human. No doubt ‘society’ pre-dated agriculture, but that was a society of marauders, looters, pillagers, hunters, or a society of wandering opportunists at best.

Agriculture brought stability to the lives of man, and this sense of stability introduced a sense of neighbourhood based on locality, a civic sense, that eventually developed to citizenship, nationality, patriotism, and all those concepts and values that are the hallmark of humanity.

My point is that it humanity is a product of agriculture. So we should focus on agriculture to maintain our evolution to the next higher stage of human development.”

– (Excerpted from www.agriwisdom.com with permission.)

Agriculture is without doubt the most important and necessary human activity. It provides us with the basic sustenance of life – food and nutrition! Apart from food crops, agriculture also gives us cash crops and medicinal crops. There are many varieties of agriculture – horticulture, floriculture, silviculture, arboriculture, olericulture, pomiculture – each of which defines and describes the purpose of that variety of agriculture.

Agriculture is rapidly becoming a critical necessity for the human race. The global population is exploding with an unimaginable ferocity. The demand for food and nutrition is inexorably outstripping the supply. We are witnessing the early stages of mass hunger and starvation. This will develop into global hunger and starvation within the next century unless we do something to reduce the supply-and-demand chasm. That ‘something’ has to be something drastic if we are to impact the supply-and-demand problem in a relatively short while. One way to solve the problem is to increase our agricultural yield manifold. Agricultural scientists all over the world are busy trying to do just that. Their research has come up with techniques ranging from radical to ultra-radical. One such technique is called hydroponics. Together with its sibling – aeroponics – it holds a lot of promise of being a viable agricultural cultivation technology for the whole world and especially for developing and under-developed nations.

“Hydroponics is steadily growing in popularity throughout the world. There are many reasons for this. First of all it is an eco-friendly method of cultivation since it minimizes use of water and potentially harmful chemicals.
The same two reasons mentioned above make it economical for the cultivator as he now has to pay out a heavily reduced bill on account of electricity (for pumping) and chemicals (for nutrients and soil beneficiation).
Hydroponics allows the cultivator to target the root system very easily, precisely and directly. The interference of soil-borne adulterants and compounds is totally alleviated in a hydroponics cultivation system.
Hydroponics allows for manipulation of crop growth more thoroughly than any other cultivation methodology. It is possible to accelerate or decelerate crop harvesting through interventions possible only through hydroponics.
The whole hydroponics cultivation setup is ideally suited for protected cultivation technology. This means it can be easily adopted by cultivators who already are using greenhouses/nethouses, etc. Nurseries are the best example of this.
In my opinion hydroponics is very suitable for developing and under-developed countries like most Asian and African countries.”
(Taken from Avinash Dubay’s LinkedIn discussion –
“Viability of Hydroponics Projects in Developing Countries” –
[Group – Hydroponics Network])

Hydroponics 101

The shortest way of describing hydroponics is – ‘soil-less cultivation’. This is not the most precise or technically correct definition of hydroponics but it is a simple and popular way of presenting the most noticeable feature of hydroponics, namely, the absence of ordinary soil for growing the seedlings for the crop!

Hydroponics is better described as a cultivation methodology that comes under the umbrella nomenclature of Controlled Environment Agriculture or CEA in short. Hydroponics attempts to control all aspects of seedling growth as directly as possible. The very first step is to remove the commonest cause of seedling mortality – soil! Therefore hydroponics replaces the traditional soil with some other growing medium. There are a number of soil-substitutes that are used in hydroponics – these soil substitutes are called substrates. The substrates are biologically neutral. The more common hydroponics substrates are: coco pith, coco peat, vermiculite, perlite, and rock wool. The suitably processed substrate is placed in trays, troughs, or individual seedling containers. Grow bags and trays are factory-prepared combinations of substrate and container. This removes the need for the substrate to be placed in the container by the cultivator.

The seed is placed in the substrate, one per cell, usually by hand but there are seedling placement machines available that do this mechanically.

After replacing soil with substrate, the next major feature is the way in which nutrients are supplied to the plant. Nutrients appropriate for the plant are mixed in the irrigation water in the proper proportion. The water is usually passed through a RO-filter to ensure its purity. This system of combining the supply of water and nutrients is known as fertigation. A fertigation system is used to distribute the nutrient solution to the plants in any one of many ways – drip and micro-sprinkler being two of the more popular methods. The distribution of the nutrient solution is done according to a schedule known as the fertigation schedule. The fertigation schedule is of critical importance to the health and well-being of the seedlings. The fertigation schedule can make all the difference between the success and failure of a crop. That is why the fertigation schedule must be designed especially for the crop being cultivated and the schedule must be designed by a professional or an expert.

The third major feature is the way in which the aerial environment is controlled. Every hydroponics project is grown inside protected environments like greenhouses and the like. This controls entry of insects, pests, birds, and animals. It also controls entry of pollutants. The seedlings are protected from disease causing organisms. The plant gets the proper growing environment by carefully controlling the temperature and humidity.

The seedling is constantly monitored for vital parameters and also for disease. The substrate is tested for operational parameters like EC/pH. The nutrient solution is tested for EC/pH and nutrient availability.

When the seedlings grow to a viable size they may be repotted or transferred out to open fields. The seedling may be sold or transported to distant places for replanting once it becomes viable.

The substrate and the trays may be reused for a number of cultivation seasons.

That, in a nutshell, is what hydroponics is all about.

Aeroponics goes one step further by removing the substrate and using just the nutrient solution.

The Fancy Steps of Hydroponics

There are many advanced techniques that are employed in hydroponics by the cultivator. These advanced techniques help to control the growth parameters more precisely and in a more timely fashion.

For example, LED lighting units are used to control the quantity and quality of light to the seedlings. Environmental growth chambers are used to control the temperature, humidity of the air.