System composition and working principle
Nutrient solution storage and circulation: The NFT hydroponic system is mainly composed of nutrient solution reservoir, water pump, planting trough and reflux device. The nutrient solution is stored in a large reservoir, and the water pump draws the nutrient solution from the reservoir and transports it to the planting trough through a pipeline. The planting trough is generally inclined, and the nutrient solution forms a very thin liquid film (usually 0.5-1 cm thick) at the bottom of the planting trough. The root system of the plant partially contacts this liquid film to absorb nutrients and water.
Oxygen supply method: In the nutrient solution reservoir, air pumps and air stones are usually used to keep the nutrient solution oxygenated. In this way, when the nutrient solution is in the circulation process, it can provide the roots of the plant with nutrient solution containing enough oxygen to meet the root breathing needs.
Advantages
In terms of facility cost
Low investment: The planting trough of the NFT hydroponic system is made of lightweight plastic or spliced ​​with corrugated tiles. The entire facility structure is light and simple, easy to install and easy to disassemble. Compared with some complex hydroponic systems, such as deep flow hydroponic systems (DFT), NFT systems do not require a large amount of capital investment in the initial construction of complex water tanks and other facilities.
Plant growth conditions
Good root oxygen supply: The intermittent liquid supply method makes the liquid layer shallow and flowing, which can better solve the root respiration oxygen demand. Because the nutrient solution layer is very thin, part of the root system is exposed to the air and can directly obtain oxygen from the air. At the same time, the flowing nutrient solution can also carry a certain amount of oxygen to the root system, thus avoiding problems such as poor growth caused by lack of oxygen in the root.
Efficient nutrient absorption: The plant roots can be in close contact with the nutrient solution film, and the nutrients in the nutrient solution can be quickly absorbed by the roots. This efficient nutrient absorption method is conducive to the rapid growth of plants, allowing plants to achieve higher yields in a shorter time.
Production management
Easy to automate management: The nutrient solution circulation and supply of the NFT hydroponic system can be controlled by simple automation equipment. For example, the timer can be used to control the opening and closing time of the water pump to achieve intermittent supply of nutrient solution. This automated management method not only saves manpower, but also improves the accuracy and stability of production.