When it comes to lettuce, a very common vegetable in daily life, everyone's first reaction is that it is delicious and delicious. Hydroponic lettuce has gradually entered everyone's field of vision, and high-quality and high-yield hydroponic lettuce is very suitable for commercial production. Lettuce, along with tomatoes and cucumbers, is one of the three major vegetables in greenhouse soilless cultivation. Due to its large plant shape, short growth period, strong cold resistance, and good yield, lettuce can be planted all year round.
What should be noted for hydroponic lettuce?
Choose the correct hydroponic method:
According to the depth of the nutrient solution layer, the structure of the facilities, and the management of oxygen and liquid supply, hydroponic culture can be divided into deep liquid hydroponic culture and nutrient liquid film technology. The nutrient layer of dwc hydroponic system is relatively deep, usually 5-15cm. The concentration, temperature, and pH value of the nutrient solution are relatively stable, and the rhizosphere environment has a large buffering capacity, making it more suitable for regions with large seasonal temperature differences in northern China. Many varieties of lettuce and herbs can grow well in dwc hydroponic system, where they grow quickly and healthily.
The dwc hydroponic system method is the most primitive method of hydroponic systems. Due to the high oxygen and nutrient rich solution, the harvesting speed of plants grown in the dwc hydroponic system is twice that of plants grown in ordinary soil. If all operations are normal, plants can be harvested in 30-40 days.
Control temperature and dissolved oxygen in water:
The suitable liquid temperature for hydroponic lettuce is 18-22 ℃, and the water-soluble oxygen content is 4-5mg/L. In hot summer, when the water temperature of the nutrient solution exceeds 30 ℃, the dissolved oxygen content in saturated water will decrease. When the water temperature reaches 50% at 0 ℃, without oxygen supplementation, the roots around the roots will be hypoxic, leading to root decay. Therefore, it is necessary to control the temperature of the nutrient solution reasonably.
Timely replacement of culture medium:
In nutrient solution hydroponics, it is important to keep the nutrient solution clean because once root diseases occur, they can quickly spread and cause irreparable losses. In addition to disinfecting the nutrient solution, it should be thoroughly updated once a month.
Hydroponic lettuce has a short production cycle, relatively controllable environmental conditions, and fewer pests and diseases. Hydroponic lettuce is carried out under relatively controllable conditions, and the probability of disease and pest occurrence is very low, but it cannot be ruled out that it will not occur. Pest control should follow the principle of "prevention first, comprehensive prevention and control", remove old and weak seedlings, remove old leaves, yellow leaves and dead leaves, clean up green algae on the surface of nutrient solution, and control the initial source of infection.
Lettuce is rich in water, with a moisture content of up to 94%~96% per 100 grams of edible parts. Due to the presence of lettuce in its stems and leaves, it has a slightly bitter taste and has analgesic, hypnotic, cholesterol lowering, and auxiliary therapeutic effects on neurasthenia. With the support of scientific planting techniques, hydroponic lettuce can be harvested in 30 days. Hydroponic lettuce has high quality and good taste, and is deeply loved by contemporary people, especially young people.