Soilless vegetable cultivation can not only improve the yield and quality of products, but also does not occupy arable land, saves fertilizer and water, simplifies the process, and is conducive to the modernization and automation of vegetable production. Its cultivation technology is:

1. Select the substrate. The substrate should be low-cost, breathable, good performance, strong root fixation, and strong water retention. Generally, inorganic granular substrates such as slag and gravel are better. Slag is light, easy to carry, and has good water retention. It is suitable for rooftops, balconies, and bungalow roofs; gravel is more stable, easy to clean, easy to disinfect, has poor water retention, is heavier, and is not easy to carry. It is suitable for use in courtyards and open fields. Generally, three grades of particles with a particle size of 0.1-0.5 mm, 1.0-2.5 mm, and 2.5-5.0 mm are selected and mixed in one third each. The total porosity can reach 45-50%, of which air pores account for 25%. The substrate used multiple times should be sieved and placed in a pool or suitable container, stirred continuously, rinsed with running water, and the residual roots and dirt should be washed away. Then, 0.1% potassium permanganate or 0.1% formalin solution is added to soak for 12-24 hours, and rinsed with running water before use.

2. Cultivation technology Soilless vegetable cultivation requires cultivation bags, generally 0.1 mm thick and 70 cm wide white polyethylene tube plastic bags, folded into double layers, with ropes on both sides to form a “U”-shaped cultivation bag with a depth of 20 cm and a cross section. According to the size of the cultivation site, prepare the corresponding number of cultivation bags, fill them with substrates, and place them neatly. Every three rows of bags are placed close together to form a 90-120 cm wide cultivation bed. Each small bed is planted with 3 rows of vegetables, that is, each bag is planted with a row of vegetables. A 60 cm wide channel is left between the beds for watering nutrient solution and manual management.

3. Prepare the solution In order to make full use of the limited area and equipment, intercrop and interplant a variety of different varieties of vegetables, and improve the multiple cropping index, it is necessary to prepare nutrient solution to supply the growth and development needs of various vegetables. The method of preparing the nutrient solution is to put the selected fertilizer into the selected container, add a certain amount of water, and the water surface is about 20 cm away from the container mouth. For fertilizers that are difficult to dissolve, they can be dissolved with hot water first, and then put into the container and add appropriate amount of water. Stir well to make the water and fertilizer solution synthesize the nutrient solution. The concentration of the nutrient solution should not exceed 0.2%, and the pH value should be between 5.5 and 6.5. Due to the evaporation of water and the absorption of nutrient ions by crops, the concentration and pH value of the nutrient solution often change, so they should be tested and adjusted frequently, usually once every 7-15 days.

IV. Watering management After soilless vegetables are planted, fertilizer is generally not added to the substrate, and nutrient solution can be used directly for watering. According to the size of the plant and the cultivation season, intermittent, regular, and quantitative nutrient solution should be used. In the early stage, less nutrient solution should be used. As the plant grows and the temperature rises, the amount of nutrient solution should also be appropriately increased. Watering should be done 2-3 times a day, and it is best to use a spray bottle for watering. It is advisable to keep the substrate moist, but not excessive, so as not to cause root hypoxia and damage the roots. The suitable temperature of the nutrient solution is 20-25℃, the relative humidity should be maintained for 2.5 hours during the day, the air content of the nutrient solution should be adjusted to 50-60%, 80-85% at night is appropriate, and the humidity is controlled at 15-30%, which can be higher in the morning and lower in the afternoon and at night, which is conducive to the accumulation of organic matter and the healthy growth of plants.

In soilless vegetable cultivation, in order to prevent falling flowers and fruits and regulate plant growth and development, biological hormones can be used comprehensively, and ethephon, dwarfing, 920, and yield-increasing spirit can be sprayed at appropriate concentrations and sprayed evenly. For pest control, in addition to selecting disease-resistant varieties and seed disinfection, strong seedlings can be cultivated, humidity can be reduced, ventilation can be carried out, and comprehensive prevention and control technical measures combining biological agents and chemical agents can be adopted. Multiple agents can be used alternately, with significant effects and high efficacy.