Tomatoes are one of the people's favorite vegetables, and the planting area is also relatively wide. Spring is the season for the rapid growth of tomatoes in greenhouses, and it is also the season when tomatoes require a large amount of fertilizer. Then, when is it better to fertilize tomatoes? Fertilization law? Let's take a look!
When should tomatoes be fertilized
According to the characteristics of tomato fertilizer requirements, tomato fertilization should be based on base fertilizer on the premise of cultivating strong seedlings, combined with soil preparation and applying 5-7 tons of high-quality organic fertilizer per acre, and 6-8 kg of phosphate fertilizer and 7-10 kg of potash fertilizer.
The tomato should be chased once every 5-6 days after planting, and 2~3 kilograms of nitrogen fertilizer (urea) should be applied per mu.
When the tomato ears begin to swell, topdressing "Fruit Fertilizer", 3 to 4 kilograms of nitrogen (urea) per mu.
When the tomato enters the full fruit period, when the ear fruit is white and the second and third ear fruit rapidly swell, topdressing should be applied 2 to 3 times, and 3 to 4 kg of nitrogen (urea) per mu each time. The previous time can be used separately 1.5~2 kilograms of phosphorus and potassium to help improve fruit quality.
After the tomato enters the fruit, the ability of the root system to absorb fertilizer decreases. Foliar sprays such as 0.3%~0.5% urea, 0.5% potassium dihydrogen phosphate, 0.1% borax, etc. can be used to delay senescence and increase the harvest period.
For tomato fertilization under protected cultivation, it is necessary to prevent salt barriers caused by excessive fertilization. When fertilizing, the input of organic fertilizer should be increased. The amount of chemical fertilizer can be reduced by 20%~30% compared with the open field, and it should be applied in small amounts and multiple times, and pay attention to timely irrigation and pressure salt to promote the growth and development of tomatoes.
Fertilization law of tomatoes
Tomatoes have a long growing period and are characterized by fruiting while harvesting. According to measurements, for every 1,000 kg of tomatoes produced, it needs to absorb 2.2 to 3.5 kg of nitrogen, 0.5 to 0.9 kg of phosphorus, 4.2 to 4.8 kg of potassium, 1.6 to 2.1 kg of calcium, and 0.3 to 0.6 kg of magnesium. From the point of view of tomato nutrient requirements, the need for potassium is particularly large, so pay attention to applying potassium fertilizer when fertilizing. The nutrient requirements of tomatoes vary according to the growth period. From planting to the end of harvest, nitrogen absorption generally showed a linear upward trend, but the fastest increase in absorption started from the fruit expansion period. After this period, the absorption rate increased, and the amount of nitrogen absorption also increased sharply, often causing nitrogen deficiency to affect fruit expansion. . The absorption of phosphorus and magnesium increases as the fruit expands. The absorption of potassium increases rapidly from the beginning of fruit swelling to the peak of fruit swelling, and its content is about twice that of nitrogen. The absorption of calcium is similar to that of nitrogen, and the lack of calcium during fruit swelling can easily cause umbilical rot in the fruit.