Introduction:


Hydroponics in practice means planting plants in water and nutrient solution without using soil. Hydroponic cultivation allows the farmer to cultivate a crop with higher efficiency in a shorter time. Hydroponic science has proved that soil is not needed for plant growth, but it requires elements in the soil (minerals, minerals). Each plant can be cultivated as hydroponics, but some of them are more successful in this system. Hydroponic cultivation is ideal for fruits with resistant crops such as tomatoes, minks, peppers, brothel plants such as lettuce, vegetables and plants that grow fast.

Nowadays, hydroponic cultivation is widely used for livestock forage production and this has become an economical and suitable way to produce livestock forage.

In hydroponic cultivation, you can make progress if you provide the right nutrient solution to provide plant requirements.
 
Most of the actions performed for hydroponic cultivation are similar to planting in soil. Hydroponic commercial cultivation includes a combination of hydroponic technology by controlling environmental factors to achieve the best quality of crop. In the greenhouse structure, you can be cultivated all year round by controlling the temperature, humidity and light.

Some of the advantages of hydroponic cultivation.


● Due to the lack of soil and weed, farming operations are simpler 
● By removing the soil, the pests in the soil are also removed. 
● In hydroponic cultivation only a percentage of water consumed in soil culture is used. Because the waters are not wasted and are not consumed by weeds. 
● In general, hydroponic crops are better in terms of food than soil cultivation. And this is due to the control of the elements and substances used by the plant. 

Plant roots:


Plant roots have two major tasks.
1- Plant maintenance in culture medium
2- Transferring water and plant required elements to all parts of it 
Water absorption is carried out by sucking water from the roots by the transpiration process, but the absorption of ions is not precisely known.


Root physicality.

There are limitations in soil cultivation for root growth, which are not these limitations in hydroponic cultivation, so they may grow more than their volume in these roots. The physical properties of roots play an important role in the absorption of elements and also in hydroponic systems, growth and development of roots are effective in plant work. 

Ventilation:

Ventilation is one of the most important factors that contribute to plant growth and root. The energy needed for root growth and absorption of ions is provided from the process of cell respiration, which requires oxygen. The solubility of oxygen in water is almost low and decreases with increasing temperature. Therefore, with increasing temperature, more oxygen should be considered for plant needs. One of the problems of hydroponic systems is lack of proper ventilation with root mass growth.

Root Environment:

Some plants have the ability to adapt to the surrounding environment. Most environmental changes are changes in PH. In addition, some plants have the ability to increase adsorption and ineffective ions by releasing substances (such as sydrofos) from their roots. This property is known as iron adequacy. In cases where the plant cannot adapt to the environment, more attention should be dediculous in the balance of the elements and control of the soluble pH. 

Temperature:


Temperature is one of the most important factors that affect the root growth and absorption of water and essential elements and ions. The optimum temperature of roots changes in different species. But in general, temperatures below 20°C cause changes in root behavior and growth. At the lowest optimum temperature, root root growth and branching decreases and the root becomes shiny. When the temperature of the roots decreases, the plant withers and due to the high air requirement per day, a shortage of elements appears. At low temperatures, the deficiency of phosphorus, iron, and manganese is more evident. About above temperatures is still unclear. Roots can withstand temperatures of up to 30 and even up to 35 °C. 

Therefore, root temperature should be set between 20 and 30 °C. 

Hydroponic culture media


From 1930 to 1950, they usually used grohl and sand. In small hydroponic units, gravule, rock wool or haddite are generally used. In commercial systems, perlite and stone wool are used more. The all culture media that are used today are peat mouse, pine bark, peat mousse mixture, pin bark and minerals such as vermicollite and perlite.

Four methods for hydroponic cultivation.

Tide systems (Ebb and Flow)
Putting plants in a culture medium
The nutrient solution is pumped from the reservoir to the culture medium in a certain period of time, the plants absorb the nutrient solution by the culture medium, and then the water goes out with drainage.

Drip System
Rockwolves Cubes.
The nutrient solution is dripping on the culture medium based on a schedule, provided that fresh water, food and oxygen are provided.

Food Film Technique (NFT)
Plant roots grow in canals. The tip of the roots is exposed to air and the bottom of them is exposed to nutrient solution.

Passive System
In this method, the plant is freely located in nutrient solution. Oxygen must be available at the bottom of the root, often by a pump. Water losses must be compensated daily.

There are various other systems, including aeroponics, in which plant roots are suspended in the environment and the nutrient solution is sprayed on it by spraying.

In general, in hydroponic system, what is important is oxygen, water, environmental conditions and the most important of them is nutrient solution. That in a successful system all of this must be observed. The above systems have been tested and their success has been proven.