Tomato Planting Nutrient

3 Management of nutrient solution
3.1 Selection of nutrient solution formula
There are many nutrient solution formulas suitable for tomato growth. You can choose a suitable nutrient solution according to the water quality of the cultivation site. Generally, the EC value of irrigation water suitable for soilless cultivation is not higher than 0.6 mS·cm!. When the calcium and magnesium ions in the water are too high, it needs to be appropriately reduced. Calcium and magnesium ions content in nutrient solution. The more common formula is: each ton of nutrient solution contains Ca(NO:)2·4H,0450.0g, KNO;375.0g, KHPO4140.0g, MgSO:7H0250.0g, EDTA-Fe 20.0g, Na,B0, 10H,0 3.0 g, MnSO:H,0 2.0 g, ZnSO:7H00.2g, CuS0:5H00.1g and Na2M004.2H200.18. During the peak flowering and fruiting period, attention should be paid to appropriately increasing the dosage of Ca(NO3)2.4H20 to prevent umbilical rot.

3.2 Nutrient solution concentration and irrigation volume management
The concentration (EC value) of tomato nutrient solution varies at different growth stages. The EC value is controlled at 1.5~2.0 mS·cm-1 from planting to before flowering, and the EC value is controlled at 2.0~2.5 mS·cm-1 from flowering to the first fruit harvest. 1. After harvesting begins, the concentration can be increased to 3.0mS·cm-1. In winter, the EC value should be appropriately increased. If it encounters continuous rain or snow, it should be increased by 20% compared with the previous 1 day; if the weather changes from cloudy to sunny, the EC value should be reduced by 0.2mS·cm-1 compared with cloudy days. This will help improve the quality. Improve and ensure output.
The amount of irrigation water should meet the plant growth needs, and should be adjusted accordingly according to the substrate volume, weather, air humidity, and plant size. Watering too frequently will cause waste of nutrient solution, root deficiency, and root retting: too little frequency can easily cause rhizosphere salts. Under appropriate watering frequency and irrigation volume, water backflow usually occurs after the second to third irrigations. The water backwater in the morning accounts for about 30% of the total water backwater, and the water backwater in the afternoon is about 70%. There is no backwater in the last two irrigations. When irrigating nutrient solutions, it is best to measure the EC value and pH value of the irrigation water and return liquid every day, and keep the difference between the EC values ​​of the irrigation water and return liquid less than -0.5 mS·cm-1 to ensure healthy plant growth.

3.3 Management of pH range of nutrient solution
The optimum pH range for tomato crops is 5.5~6.5. Generally, the pH shows an upward trend during cultivation. When the pH is less than 7.5, the growth of tomatoes is in a normal state; but when the pH value is too high and greater than 8, it will destroy the balance of nutrients and cause the loss of Fe, Mn, B, P, etc. Precipitate, causing nutrient deficiency. At this time, the pH value range must be adjusted in time.

4 Cultivation and management
4.1 Temperature, humidity and light management
1) Light management: Tomatoes have high requirements for light intensity, and their light saturation point is 700001x. Therefore, in order to produce high-quality tomatoes in winter, tomatoes need to be supplemented with light. Generally, 1 hour of light is used in the morning and afternoon. 2) Temperature control: generally 26~28℃ during the day and 12~14℃ at night; 24~26℃ on cloudy days and 10~12℃ at night on cloudy days. 3) Humidity control: relative humidity 75% before flowering and 55%~65% during flowering period.