In protected environments, peppers can also be grown without soil using a hydroponic system. The substrates used in hydroponic cultivation can be organic, inorganic, or synthetic. Organic substrates include coconut coir, rice husks, sawdust, bark, and pine needles; inorganic substrates include rock wool, vermiculite, perlite, quartz sand, and expanded clay; synthetic substrates include expanded polyurethanes, expanded polystyrenes, and urea-formaldehyde.
Regardless of their origin, the substrate must be inert and stable (it should not decompose, dissolve, or significantly alter the composition of the nutrient solution), clean, allow easy drainage of excess nutrient solution, and have a favorable balance of micro and macro capillaries.
Advantages of Hydroponic Cultivation:
- No crop rotation required
- Reduced occurrence of pathogens
- Less use of plant protection products
- Reduced environmental pollution
- Cultivation on surfaces unsuitable for traditional farming
- High production intensity
- High degree of automation
- Less labor required for processing, cultivation, and disinfection
- Reduced water and nutrient consumption
Cultivation on Rock Wool
Rock wool is a fibrous substrate made from basalt, limestone, and coke at a temperature of 1600°C, making it completely sterile. It has a low bulk density (70 kg/m³), a high pore volume, high water capacity, and good absorption properties. The soil in the protected area is covered with white plastic sheeting, and polystyrene panels, which are good thermal insulators, are placed along the rows. Additional heating pipes can also be installed in these panels. The rock wool slabs are wrapped in black-and-white film, and openings are made for the seedlings. Seedlings grown in rock wool cubes, wrapped in film, are placed on the slabs at planned intervals. A drip irrigation system is used to apply a nutrient solution tailored to the plant’s developmental needs.