How to fertilize fruit trees in summer?

How do fruit trees top dressing in summer? Please describe the method In the middle and late June, grape, pear and other fruit trees began to expand in the first rapid expansion period. The flower bud is at the physiological differentiation stage, and its root system grows rapidly and absorbs actively, which is easy to appear the phenomenon of defertilization. In this critical period, proper amount of topdressing can supplement the nutrients needed by the tree body, promote flowers and fruits, and topdressing with total element fertilizer containing nitrogen, phosphorus, potassium and trace elements and special fertilizer for fruit trees is better. Usually, radial fertilization accounts for 53% of the whole year. Summer topdressing can promote fruit expansion and flower bud differentiation. There are two topdressing methods: root application under trees and foliar spraying. 1. Topdressing under roots. The topdressing of fruit trees in summer should be mainly phosphorus and potassium fertilizers combined with a small amount of nitrogen fertilizer. The amount of topdressing depends on tree species, age, fruit yield and base fertilizer status. For young trees that have not entered the fruiting period, 0.2-0.25 kg of phosphorus and potassium fertilizers can be applied to each plant. For common fruit trees, calcium superphosphate 2.5-3 kg, plant ash 10-15 kg and ammonium sulfate 2 kg are applied to each tree. The topdressing method comprises the following steps of: digging holes in a circle at the position from the vertical downline to the inner 1 meter of the tree crown, wherein the distance between the holes is 30-40 cm, and the depth of the holes is 15-20 cm; and covering the holes with soil after the topdressing is applied. Conditional orchard watering after topdressing. II. Foliar fertilizer spraying. Spraying foliar fertilizer at fruit expansion stage can strengthen tree vigor, promote fruit expansion and improve fruit quality. The spraying concentration is ammonium sulfate 0.2%, urea 0.3-0.5%, potassium sulfate 0.3%, calcium superphosphate 1-3%, potassium dihydrogen phosphate 0.3%. Foliar fertilizer spraying on fruit trees in mountainous areas is more effective. Click for more compound fertilizer application techniques Click for more fertilizer application techniques