What are the different methods of soilless cultivation? Three kinds of water culture, fog culture and substrate (with advantages and disadvantages)

There are three kinds of soilless cultivation methods: water culture, fog culture and substrate cultivation. Hydroponic culture: direct contact between plant roots and nutrient solution, without substrate. Aerosol culture: the nutrient solution is compressed into an aerosol and sprayed directly on the roots of crops. this method is too expensive and has not been widely used for the time being. Substrate cultivation: crop roots are fixed in organic or inorganic substrates and nutrients are provided to crops through drip irrigation. This method has been widely used because of its simple operation, low cost and low investment.

I. hydroponic culture

Hydroponic culture actually makes direct contact between plants and nutrient solution, and does not require the planting method of substrate. The earliest hydroponic culture is to directly invade the plant into the nutrient solution to let it grow, but it is prone to hypoxia, so as to affect root respiration and seriously lead to root death. Later, in order to solve this problem, someone in Britain put forward the hydroponic culture method of nutrient liquid membrane.

Principle: a very thin layer of nutrient solution, about 1cm, circulates through the crop roots, not only ensuring the supply of nutrients and water to the crops, but also providing fresh oxygen to the roots. This irrigation technique is much simplified, and after the root system is isolated from the soil, a variety of soil-borne diseases and insect pests can be avoided, and there is no need for soil disinfection.

2. Fog culture

Aerosol culture can also be called aerosol culture, which compresses the nutrient solution into an aerosol shape and then sprays directly on the root system of the crop, which is suspended in the space of the container. However, the equipment cost of this method is too high, it also needs to consume a lot of power resources, and can not be cut off, this method is only suitable for scientific research and application, can not be used in large-scale production.

1. Generally use polypropylene foam board to drill holes according to a certain distance and plant them in the holes.

2. Build the two foam plates obliquely into a triangle to provide space for the liquid pipe to pass through the middle of the triangle and spray directly on the overhanging root system.

3. Spray for a few seconds every 3 minutes or so, so that the nutrient solution can be recycled and the oxygen needed by the crop roots can be ensured.

III. Substrate cultivation

Substrate cultivation is the largest way to popularize in soilless culture. its principle is to fix the roots of crops in organic or inorganic substrates, and then provide nutrients to crops by trickle irrigation or drip irrigation.

The cultivation substrate can be packed in plastic bags or spread in cultivation ditches or grooves. The nutrient solution of substrate cultivation will not be recycled, which is also called open-circuit system, which can also avoid the spread of diseases.

The buffer capacity of substrate cultivation is strong, there is no contradiction between water, oxygen supply and nutrients, and the equipment is simpler than water culture or fog culture, does not need any power, has low cost and low investment, and has been widely used in production. this is a very practical method of soilless cultivation.