How to apply fertilizer outside the root?

Exogenous fertilization is an auxiliary fertilization method which sprays water-soluble liquid fertilizer on leaves and is directly absorbed and utilized by leaves. Compared with soil fertilization, it has the advantages of less dosage and quick effect, but the fertilizer effect of external fertilization is short, which can not fully meet the needs of sustainable growth of mulberry trees, and is only a supplement to soil fertilization in mulberry fields.

(1) fertilizer type and concentration

Water-soluble nitrogen, phosphorus and potassium fertilizer are the main raw materials. In the early stage of mulberry growth, when the mulberry garden is short of fertilizer or the weather is dry, nitrogen fertilizer is generally sprayed to promote the vigorous growth of mulberry leaves. When the weather is rainy and the sunshine is insufficient, phosphorus and potassium fertilizers are sprayed to promote the maturity of mulberry leaves. Spraying concentration: 0.5% urea, 0.4% ammonium sulfate, 0.5% ~ 1.0% calcium superphosphate, 0.5% potassium sulfate, 1.0% plant ash (leachate). The spraying amount per mu is100 ~150kg aqueous solution.

(2) Spraying time

Spray it in the morning or evening on sunny days, and spray it in the morning after the dew dries.

(3) Spraying site

Spraying liquid mainly enters mesophyll tissue through stomata on the back of leaves, so it should be sprayed on the back of mulberry leaves as much as possible.

(4) spraying times

Generally, spray 1 time every 2 ~ 3 days, and spray continuously for 2 ~ 3 times to achieve the effect, and appropriately increase the spraying times in dry season.

When applying fertilizer outside the roots, pesticides can be mixed into the fertilizer, which can be combined with the prevention and control of diseases and pests in mulberry fields, which can prevent and control diseases and pests, increase mulberry leaves and save labor, but attention should be paid to the interaction between fertilizers and pesticides.