Hydroponics is the method of growing vegetables without any soil. It deals with growing vegetables on a nutrient solution. Crops like leafy vegetables (Lettuce, Kang Kung, Gotukola) and vegetable crops like tomato, eggplant, green bean, winged bean, capsicum, cauliflower, cabbage, bell pepper can be grown by the non-circulating method of hydroponics.
In this method nutrient solution is taken in a container made out of Styrofoam or wooden boxes or plastic buckets or cement troughs except metal containers. Within these Styrofoam is the best one (it can maintain the temperature of nutrient solution).
How to prepare the box?
Take a box of 30 cm height. Cover the inside of the box with black polythene of 0.15 mm thick. A board with holes to cover the box is made out. The board must contain an additional hole to ensure the air circulation. Nutrient solution can be filled up to the height of 20 cm. The above space provides enough air circulation to the root system.
Ideally top 2/3 of young root system must be in the air and the rest must be floating or dipping in the nutrient solution.
Plastic cups with holes on the bottom and sides can be used for this purpose (roots emerge through them and seepage of nutrient solution into the potting material occurs).
Commonly old coir dust is used as potting material. Small pieces of nets are placed inside the pot to prevent fall off of potting material. Seeds can be directly raised on these pots.
The planting pots with seedling are fixed to the holes on the board. During maintenance if the solution level goes down it must be siphoned out and replaced with fresh solution.
Preparation of nutrient solution
Farmers can prepare nutrient solution in their own by dissolving compatible (no reaction between them) water-soluble nutrient salts. In the market different formulations are available to prepare the nutrient solution.
The nutrient solutions must be free from impurities like sand/clay. At the same time urea can't be used as a nutrient solution. Because it doesn't change into ionic forms to absorb by plants.
The followings are the combinations of soluble fertilizers can be used for nutrient solutions:
Ammonium nitrate (AN) can be used with any one of the nutrient salts like Ammonium sulphate (AS) or Calcium nitrate (CAN) or Mono ammonium phosphate (MAP) or Potassium sulphate (SOP) or Potassium chloride (MOP) or Potassium nitrate (PN).
(MOP) can be used with any one of the nutrient salts like AN or AS or CAN or MAP or SOP or PN.
To prepare 1,000 litres of nutrient solution following chemicals are required (the Albert's mixture is locally available in the market)
These amounts are completely dissolved in water and volume is adjusted upto 1,000 litre by adding of pure water.
Training and pruning system can be adopted to provide supports to tall growing plants and heavy fruit bearing plants.