The hydroponic cultivation styles can be classified into four core types based on "the presence or absence of substrate" and "the method of nutrient solution supply". Each type has its own applicable scenarios and operational characteristics. The specific classification and details are as follows:
Substrate cultivation: Utilizing solid substrates to fix the root system, with sandstone, rock wool, coconut coir, etc. as the carriers, to adsorb the nutrient solution for the crops to absorb. The operation threshold is low and the stability is strong, making it suitable for large-scale production.
Rock wool cultivation: The mainstream style in Dutch greenhouses, using block-shaped rock wool (10cm × 10cm × 7.5cm) to fix the plants, with the nutrient solution passing through drip irrigation tubes directly to the substrate, suitable for tomatoes, cucumbers, etc. of fruit vegetables, with a water and fertilizer utilization rate of over 95%, but attention should be paid to the recycling and treatment of rock wool.
Coconut coir cultivation: An environmentally friendly style, compressing the coconut coir into blocks, soaking them, and then filling them into planting bags/slots, combined with a drip irrigation system, suitable for strawberries, lettuce, etc. The substrate can be recycled for 2-3 seasons, and the cost is lower than rock wool.
Substrate trough cultivation: Using bricks or foam boards to build planting troughs, filling them with perlite and vermiculite mixed substrates, suitable for leafy vegetables (such as lettuce, romaine), with simple management and suitable for beginners to try.
II. Hydroponics: The root system directly contacts the nutrient solution
Without solid substrates, the root system is suspended or semi-immersed in the nutrient solution, with efficient nutrient absorption, suitable for high-value crops.
NFT deep-flow cultivation: The root system is partially immersed in 5-10cm deep flowing nutrient solution, with sufficient oxygen, commonly used for lettuce, water spinach cultivation, with the advantages of water and fertilizer conservation, but the requirement for controlling the nutrient solution concentration is high.
DWC deep-water cultivation: The root system is completely immersed in oxygen-rich nutrient solution (requiring an aeration device), suitable for watercress, tilapia (fish-vegetable symbiosis), with fast growth, but needs to strictly prevent nutrient solution contamination.
Fog cultivation (air cultivation): Using a fogging nozzle to spray the nutrient solution into a mist form, directly acting on the root system, with the root system suspended to absorb nutrients and oxygen, suitable for tomatoes, cucumbers, etc. of fruit vegetables, with high yield, but the equipment cost is high and requires continuous power supply.
III. Vertical cultivation: Vertical space utilization type
Derived from the above two methods, improving the yield per unit area, suitable for greenhouses with limited space.
Vertical rock wool cultivation: Multi-layer frame structure, placing rock wool blocks on each layer, combined with drip irrigation, used for strawberries, tomatoes, with a per-acre yield of up to 3-4 times that of traditional cultivation.
Vertical hydroponic tower: Cylindrical or square tower bodies, with layers of planting holes, nutrient solution flowing down from the top, suitable for leafy vegetables, beautiful and space-saving, often used in tourist greenhouses or home cultivation.
IV. Other special styles
Fish-vegetable symbiosis: Combining hydroponics and aquaculture, the fish feces are decomposed by microorganisms to become the nutrient solution for the crops, and the water purified by the crops is returned to the fish for breeding, forming an ecological closed loop, suitable for organic vegetables and ornamental fish co-culture, environmentally friendly and high value.
Substrate bag cultivation: Filling the substrate into PE planting bags, planting crops with holes on the side of the bag, suitable for balconies, small-scale greenhouses, flexible movement, and adjustable spacing according to the growth of the crops.
