The number and time of top dressing in the orchard should be based on the characteristics of the apple tree's requirements:

The first top dressing is topdressing before flower bud differentiation, which is the budding period; the second top dressing is after the flower fades, and the fruit hangs for 15 days, which is the young fruit period. The third top dressing was in the fruit swelling stage and before the flower bud differentiation.

These time points are also the time nodes when the fruit trees need water. Watering after top dressing can better promote absorption; if you use water-soluble fertilizer top dressing, you can flush with water or use a fertilizing gun.

What should I focus on this time (the second time in the year)? This top dressing is mainly quick-acting fertilizer, highlighting phosphate fertilizer and potash fertilizer, controlling nitrogen fertilizer, and promoting flower bud differentiation and young fruit development as the main purpose. You can choose urea, diammonium phosphate, NPK compound fertilizer, or NPK and medium trace amounts. Elemental water-soluble fertilizer.

The amount of fertilizer for apples is generally:

Apply 0.05-0.25 kg of urea, 0.3-0.4 kg of diammonium phosphate, 0.5-0.7 kg of compound fertilizer, or 0.3-0.4 kg of NPK compound fertilizer to young trees;

Apply 0.5-0.7 kg of diammonium phosphate, 1-1.5 kg of compound fertilizer, or 0.5-0.7 kg of NPK compound fertilizer to apple trees, and irrigate in time after fertilization. Supplemented with page spraying: because in the young fruit stage, cell division and peel formation require a lot of boron, boron deficiency directly leads to rough peels, and severe boron deficiency can cause fruit shrinkage. Boron supplementation can promote calcium absorption; Calcium is also the key to increase fruit firmness, reduce physiological diseases, and have an obvious effect on preventing red and black spots

.

Finally, top dressing can be applied in acupuncture points or shallow trenches.

Hole application: dig 6-10 fertilization holes 40-50 cm deep in the fruit tray under the tree, mix the topsoil and topsoil, and fill the soil; shallow trench method dig a 10 cm ring or half ring in the fruit tray If the topsoil is shaped like a ditch, sprinkle the top-dressing fertilizer into the ditch.