The best time for citrus potash fertilizer

Potassium is one of the essential elements for plants. Potash fertilizer can enlarge the fruit, so it needs to be applied at the right time when planting citrus. When is the best time for citrus potash fertilizer?

I. the best time for citrus potash fertilizer

The application of citrus potash fertilizer is usually in the period of fruit expansion and strong fruit from June to July and after fruit harvest in early November. The application of potash fertilizer must be combined with nitrogen and phosphorus fertilizer to exert its fertilizer effect.

II. Fertilization methods for citrus

Citrus fertilization methods, generally speaking, there are soil fertilization and extra-root topdressing, also known as foliar fertilization.

The main results are as follows: 1. Soil fertilization must be applied in the root distribution layer according to the distribution characteristics, so it is also called "rhizosphere fertilization". The fibrous root (absorbing root) of citrus is mainly concentrated outside the periphery of the crown, and its root system has fertilizer tendency, and its growth direction is often transferred by fertilization. Young trees should induce horizontal roots and absorb roots by fertilization. generally, organic fertilizer should be applied a little deeper and farther away from the root concentration layer to induce the root system to grow deeper and wider to form a strong root group. The application of basic fertilizer in mountain orchards should be 30-40 cm deep, and topdressing should be applied in shallow ditches. The position of fertilization and ditching should be outside the vertical projection of the crown (commonly known as the external dripping line of the crown) and should not be applied under the tree head.

The methods of fertilization are as follows: (1) fertilization in ring furrow. Along the tree crown dripping line, dig 15-20 cm deep, 30 cm wide circular fertilizer ditch, cover the soil after application. It is mostly used for young trees.

(2). Fertilization in radiation ditch. Trench 1-1.5 meters away from the trunk in the crown. 4-6 trenches are radially dug outward according to the size of the crown. The depth and width of the trench is the same as that of the annular trench, but attention should be paid to the shallow inside and deep outside to avoid injuring the big root. Change places every year.

(3) burrowing fertilization. Within the canopy, several holes are dug and covered with soil, which are staggered every year.

(4) fertilization in furrow. It is a common way to open a groove with a depth of 20-30 cm and a width of 30 cm on both sides of the crown, and the length of the groove depends on the size of the crown. Rotate the position every time.

2. Extra-root topdressing is simple and easy, the amount of fertilizer used is small, and it can play a role quickly, which can meet the urgent needs of fruit trees in time, and avoid the failure of some elements in the fixed role in the soil. However, extra-root topdressing can not replace soil fertilization.

After spraying fertilizer on the leaves, it can be absorbed from 15 minutes to 2 hours. The young leaves absorb faster than the old leaves, and the back of the leaves absorb faster than the leaves. Therefore, the leaf back should be sprayed more. In addition, tender shoots, branches, stems and fruits can be absorbed.

Extra-root topdressing, promoting flower bud differentiation and protecting flowers and fruits all play an important role.

Fertilizer and concentration used for external topdressing: urea 0.3-0.5%, potassium dihydrogen phosphate 0.2-0.4%, magnesium sulfate 0.5-1%, zinc sulfate, manganese sulfate 0.1-0.2% (plus 0.25-0.1% hydrated lime) borax 0.1-0.2%, ammonium molybdate 0.05%.

Citrus fertilization needs to be combined with growth, and more attention should be paid to it in daily management.