What are the environmental requirements for growing lettuce?
Lettuce is one of the most common leafy green vegetables in our daily lives. Both the tender leaves and the leaf stems of lettuce can be eaten raw, which is how it got the name "shengcai" (raw vegetable). Nowadays, when people eat barbecue or hot pot, lettuce is almost always an essential vegetable. As a result, the lettuce market is growing larger and larger, and more and more people are growing it. However, growing lettuce has certain environmental requirements. Below, let us walk you through the environmental requirements for lettuce!
1. Temperature
Lettuce is not suited to growing in high-temperature environments; it is a vegetable that prefers cool conditions and tolerates frost. After sowing, it can germinate as long as the temperature is kept above 5°C, with the most suitable germination temperature being around 18°C. Below 15°C, the germination speed will be affected to some extent, and germination will be uneven, with some early and some late. Above 30°C, the seed coat becomes hard and the germination rate decreases. After germination, the growing temperature must not be lower than 12°C, though the lowest temperature that seedlings can withstand is around 4°C. Above 22°C, lettuce is very prone to early bolting, which reduces yield and quality. Overall, throughout the entire growth period of lettuce, keeping the temperature at 18-22°C is sufficient.
2. Light
Lettuce has a relatively high demand for light. During cultivation, sufficient light must be ensured. If light is insufficient, the growth of lettuce will be greatly hindered, the leaves will be thin, the head will not be compact enough, and yield will be reduced. Therefore, when planting, we should pay attention to planting density and avoid planting too densely, to prevent it from affecting the light absorption of lettuce and causing it to only grow leaves without forming heads. However, light should not be too intense either. If the inner leaves are exposed to direct sunlight, the heading rate will also be reduced. So in summer, shading work should also be done well and management strengthened to ensure planting benefits.
3. Water
The roots of lettuce are not deeply distributed, and the leaf area is relatively large, so the rate of water evaporation is fairly fast, and lettuce is quite sensitive to the moisture content of the soil surface. Therefore, throughout the entire growth period of lettuce, sufficient water must be ensured. However, lettuce has different water requirements at different growth stages. For example, during the seedling stage, water should not be excessive, to prevent the seedlings from aging and to avoid excessive vegetative growth. During the heading stage, sufficient water must be ensured; insufficient water will reduce the quality of lettuce, resulting in small heads and a bitter taste. After heading, water should be controlled to prevent excessive water from causing the heads to crack.
4. Nutrients
Lettuce has a weak ability to absorb nutrients and has relatively high requirements for soil oxygen content. Therefore, when choosing a planting site, we should select sandy soil with high terrain, normal drainage and irrigation, sufficient fertility, and strong permeability. The content of nitrogen, phosphorus, and potassium in the soil is very important for the growth of lettuce. Moreover, because lettuce has a short growth cycle and high yield, its demand for nutrients is very great, so we must ensure sufficient nutrients during cultivation. In addition to increasing the use of nitrogen, phosphorus, and potassium fertilizers, calcium, magnesium, and other trace fertilizers should also be appropriately supplemented. A deficiency in any one nutrient will affect the growth of lettuce and cause various problems.
The above is a brief introduction to the environmental requirements of lettuce. It should be noted that when choosing soil, we should not choose plots with high rainfall and low-lying, uneven ground. Otherwise, water is very likely to accumulate, causing lettuce root rot, and triggering diseases and pests such as downy mildew and root rot. This seriously harms the growth of lettuce, leading to decreased yield and reduced quality. That is all for today's introduction. This article is for reference only. Thank you for reading and your support.