What is the appropriate amount of fertilizer for young jujube trees?

Fertilizing can promote vigorous growth of young trees and bring them into production early. Generally, in the first year, apply 50 grams of urea and 150 grams of compound fertilizer per tree; from the second to the fourth year, apply 15 to 20 kg of farmyard manure, 0.2 to 0.3 kg of urea, and 0.5 kg of compound fertilizer per tree. When fertilizing, for soil with a high sand content, apply small amounts multiple times; for clayey soil, the amount of organic fertilizer can be appropriately increased.