When is it better to fertilize tomatoes? What are the fertilization rules?

Tomatoes are one of people's favorite vegetables, and the planting area is also relatively wide. Spring is the season for the rapid growth of greenhouse tomatoes.

When should tomatoes be fertilized

According to the characteristics of tomato fertilizer demand, under the premise of cultivating strong seedlings, tomato fertilization is mainly based on base fertilizer, combined with land preparation, 5-7 tons of high-quality organic fertilizer per mu, and 6-8 kg of phosphorus fertilizer and 7-10 kg of potassium fertilizer.

Tomatoes should be chased once 5 to 6 days after planting, with 2 to 3 kg of nitrogen fertilizer (urea) per acre.

When the tomato ear starts to swell, topdress "fruit fertilizer" and apply 3-4 kg of nitrogen (urea) per acre.

When the tomato enters the full fruit period, when the ear fruit turns white and the second and third ear fruit expands rapidly, top dressing should be applied 2 to 3 times, with 3 to 4 kilograms of nitrogen (urea) per mu each time. 1.5 to 2 kg of phosphorus and potassium to improve fruit quality.

After the tomato enters the full fruit, the root system's ability to absorb fertilizer decreases, and foliar spraying can be carried out, such as 0.3%~0.5% urea, 0.5% potassium dihydrogen phosphate, 0.1% borax, etc., in order to delay senescence and increase the harvest period.

For tomato fertilization under protected ground cultivation, it is necessary to prevent the salinity barrier caused by excessive fertilization. When fertilizing, the input of organic fertilizer should be increased. The amount of chemical fertilizer can be reduced by 20% to 30% compared with the open field, and it should be applied in small quantities and several times, and attention should be paid to irrigation and salt pressure in time to promote the growth and development of tomatoes.

Fertilization rules for tomatoes

Tomatoes have a long growing season and have the characteristics of fruiting while harvesting. According to the determination, every 1000 kilograms of tomatoes need to absorb 2.2-3.5 kilograms of nitrogen, 0.5-0.9 kilograms of phosphorus, 4.2-4.8 kilograms of potassium, 1.6-2.1 kilograms of calcium, and 0.3-0.6 kilograms of magnesium. From the perspective of tomato nutrient needs, the demand for potassium is particularly large, and it is necessary to pay attention to the application of potassium fertilizer when fertilizing. Nutrient requirements of tomatoes vary by growing season. From planting to the end of harvest, nitrogen absorption generally shows a linear upward trend, but the fastest increase in absorption starts from the fruit expansion period. After this period, the absorption rate increases and the nitrogen absorption also increases sharply, which often easily causes nitrogen deficiency to affect fruit expansion. . The absorption of phosphorus and magnesium increases with the expansion of the fruit. The absorption of potassium increases rapidly from the beginning of fruit expansion to the peak of fruit expansion, and its content is about twice that of nitrogen. The absorption of calcium is similar to that of nitrogen, and the lack of calcium in the fruit expansion stage is easy to cause umbilical rot in the fruit.