Do you need topdressing to grow lettuce? How to apply fertilizer correctly?

Planting lettuce requires topdressing. Because lettuce belongs to leafy crops, nitrogen fertilizer is generally the main topdressing. In addition, according to different planting seasons, the method and dosage of topdressing are also different. Let me tell you in detail.

First, the characteristics of lettuce on fertilizer requirements

Lettuce grows rapidly, likes nitrogen fertilizer, and absorbs less fertilizer at the initial stage of growth. 70 ~ 80 days after sowing, the fruit-bearing period begins, and the nutrient absorption will increase sharply at this time. In the month of lettuce fruiting period, the absorption of nitrogen will account for more than 80% of the whole growth period, and the absorption of phosphorus and potassium is almost the same as that of nitrogen, especially potassium, which will not only seriously affect the weight of lettuce leaves in the heading period, but also have the greatest impact on the growth in the seedling period. Lack of phosphate fertilizer at heading stage will affect the heading of lettuce.

Second, the correct topdressing method of lettuce

The cultivation methods of lettuce are divided into open field cultivation and protected field cultivation. Different cultivation modes have different fertilization methods. In the case of sufficient base fertilizer, its topdressing is as follows.

1, topdressing method for open field cultivation

Because lettuce is mainly eaten raw, it is not suitable for manure of topdressing people. Nitrogen fertilizer is usually the main fertilizer, and topdressing should be carried out three times during the whole growth period. 65,438+0 times after slow seedling, 65,438+0 times at the clumping stage and 65,438+0 times at the core-covering stage, and 8 ~ 65,438+02 kg of urea or ternary compound fertilizer was applied topdressing each time. Rinse with water.

During the whole growth period of lettuce, it is necessary to ensure sufficient and even water supply, keep the soil moist frequently, extend the supply period in the middle and late stage of heading to prevent the lettuce leaves from rotting, and then properly control watering.

2. Topdressing method of lettuce in protected cultivation

Lettuce cultivation and seedling raising in winter and spring is in the severe winter. Generally, seedlings should be raised in sunlight greenhouse or sunlight bed. When sowing at 9 ~ 10, seedlings can be raised in the open field. If you sow in June ~ 1 1 ~ 12, you need to raise seedlings in solar greenhouse or greenhouse.

Lettuce seedlings should be watered for 7 days, then cultivated again and appropriate measures should be taken to squat seedlings. After 15 days, the rosette leaves have grown out, and when the heart leaves begin to be wrapped, ternary compound fertilizer or urea 1 5 ~ 20kg should be topdressing, and topdressing1time at heading stage. Be careful not to water too many times in winter to prevent low temperature or high humidity. At heading stage, the water supply must be kept even, and it is forbidden to dry and wet suddenly, so as to prevent and avoid lettuce from cracking or making bulbs open and grow, which will affect the commercialization of lettuce.

In the process of lettuce planting, it is common to apply nitrogen fertilizer and less phosphorus and potassium fertilizer, which will lead to low yield and poor quality of lettuce. Attention should be paid to the coordination and balanced application of various nutrient elements in the process of lettuce planting. Lettuce fertilization should be based on nitrogen fertilizer, but it still needs to be combined with phosphorus and potassium fertilizer. May I remind you that calcium deficiency in lettuce is easy to cause? Dry burning heart? This phenomenon leads to leaf bulb rot.