Home

Health

Organic Terrace Garden

Indian Recipes

HPS 1976

Travel Log

Wheat Grass

Wine

Farming

Hydroponics

Hydroponics is a method of gardening without soil. By eliminating the soil, one also eliminates a large number of soil borne pests & diseases. Inputs can be optimized to achieve greater control over the plants.

A simple hydroponic system requires a container to hold the aggregate and nutrient solution. The aggregate is an inert medium for providing a support structure for the roots. Some examples of materials which can be used as aggregates are sand, gravel, rockwool, perlite, vermiculite and shards of brick. I have even used a block of sponge to serve as an aggregate to make an interesting display!

Use of aggregate is not essential and can be eliminated if a method of supporting the plant can be worked out. I have used a clay vessel with a narrow neck. Plant support was achieved by wrapping a sponge around the stem of the plant and inserting it into the vessel so that the sponge is firmly wedged in the neck and the roots freely dangle in the nutrient solution. As the plant grew, external supports were used to support the folliage.

Nutrient solution can be prepared from a ready-made dry mix formulation by mixing 1 level teaspoon in 3.8 liters of water. This will give a pH in the range of 6 to 6.5 .

A simple formulation for a dry mix nutrient is shown in the table below:

Fertilizer Salts

Quantity in Grams

Nutrients Supplied

Sodium Nitrate

350

Nitrogen

Potassium sulphate

110

Potassium, sulphur

Superphosphate

140

Phosphorus, calcium

Magnesium sulphate

100

Magnesium, sulphur

Iron sulphate

A pinch

Iron

There are two methods of applying the nutrients, active and passive. In the active method, the nutrient is pumped onto the aggregate and allowed to drain off. This method is difficult to implement without automation. In the passive method, the nutrients are allowed to be wicked up from a reservoir into the aggregate. In my passive method (using a clay vessel with a narrow neck) the aggregate was eliminated and the nutrient solution was directly filled into the vessel. Although literature cautions against water-logging, the variety of plants I have grown did not appear to suffer from this problem since plants grown hydroponically quickly adapt to the situation by growing special roots which trap air within them.

The nutrient solution must be periodically replaced since replacing only the nutrients consumed is not a viable proposition unless one has the expensive setup to carryout chemical analysis. I have replaced the nutrient solution every alternate day and used the spent solution to water other plants which were being grown conventionally in the soil. Every day the nutrient solution was topped up in the container with water to compensate for evaporation and to keep the pH within the acceptable range.

I have grown tomatoes, cucumbers and capsicums by the method outlined above. Tomatoes are perhaps the easiest to grow. I was delighted with the vigorous growth of my plants which grew as vines to a height of 6 feet. The plants were grown in the open but I provided a screen above to diffuse the strong sunlight in summer to prevent scorching the leaves.

I came to know about Hydroponics after reading a wonderful book by Richard E. Nicholls entitled "Begining Hydroponics" which is a beginner's guide to growing vegetables, house plants, flowers and herbs without soil. The book is published by Running Press, Philadelphia, Pennsylvania.

Home

Health

Organic Terrace Garden

Indian Recipes

HPS 1976

Travel Log

Wheat Grass

Wine

Farming