Citrus

1. Nutritional characteristics

Citrus is a perennial woody plant with early bearing period, long bearing period and large flowering amount. It usually shoots three times in spring, summer and autumn in a year. Citrus roots are particularly developed, mainly distributed in the 60cm soil layer, especially in the 15-40cm soil layer.

2, need fertilizer characteristics

In the whole growth period of citrus, the amount and proportion of nitrogen, phosphorus and potassium are different due to different factors such as soil, climate, varieties and planting methods. Orchards with more than 3000 kg per mu need to apply nitrogen (N) 25 ~ 35kg, phosphorus (P2O5) 8 ~ 12kg, potassium (K2O) 20 ~ 30kg per mu.

The absorption of nutrients by citrus showed seasonal regularity. The nitrogen, phosphorus and potassium absorption of citrus shoots began in April, reached the peak in June, and gradually decreased from July to October. During fruit development, the absorption of nitrogen, phosphorus and potassium gradually increased in June, peaked from August to October, and then the absorption tended to be stable. The results indicated that April to October was the period of maximum fertilizer absorption in the annual cycle of citrus.

The lack of calcium, magnesium, zinc, boron, manganese and other trace elements can be shown in fruits and leaves, affecting the growth and development of citrus, quality decline, such as calcium deficiency subspecies will lead to yellow leaf tips, easy to crack fruit, fruit hardness is low; Boron deficiency can affect flowering and vein protrusion; Magnesium deficiency affects photosynthesis in leaves. (Taken from the network, if there is infringement, please contact to delete.)

3. Fertilization technology

It is recommended to apply strong high-nitrogen and high-potassium special formula fertilizer (18-8-16, 15-7-13), and the application amount of mandarins, oranges, navel oranges and lemons per plant is 1.5-3kg. The application amount of pomelo per plant is 2 ~ 4 kg. Winter fertilizer (or spring fertilizer) and strong fruit fertilizer are applied according to 60% and 40% of the total fertilizer.

Ditch application or hole application along the drip line of the tree crown, the depth of fertilization is 20 ~ 40cm, covering the soil, or spreading the soil.