1. Fertilization of young trees: Young trees mainly cultivate the branches and accelerate the growth of the canopy. After 15-20 days after the pomelo planting, new roots are started. At this time, the decomposed human excrement should be pursued. The annual roots of the tree roots are weak in fertility, and the principle of “diligent application” should be adopted. 2-3 times a month, the fertilizer concentration is gradually increased from light, and each tip is guaranteed to have 1-2 heavy fertilizers. -20 days per plant applied a thicker human and animal manure 5-10 kg plus urea 0.1-0.2 kg, can also be used to make decomposed peanuts 1 kg plus urea 0.2 kg tips, and then once again as a strong shoot fertilizer. Fertilization should be applied by plate application or circular shallow ditch. Winter fertilizer or heavier fertilizer should be applied deep, and the length, width and depth of each hole should be 60×30×30 cm, and the hole position should be perpendicular to the periphery of the canopy. The new shoot period can be sprayed with 0.4% urea + 0.5% magnesium sulfate solution to accelerate greening.

2. Results tree fertilization: The result tree is generally applied 4-5 times of fertilizer throughout the year, with emphasis on applying the second heavy fertilizer before harvesting and before flowering. The fruit harvesting fertilizer is applied in the middle and late October, and the more trees can be fertilized earlier. This fertilizer is the most important one. In order to prevent the late autumn shoots and the winter shoots, the organic fertilizer, phosphate fertilizer and potassium fertilizer should be applied. Mainly, less nitrogen fertilizer, its role is to restore the tree potential, increase the nutrient accumulation of the tree, is conducive to germination and differentiation, this fertilizer should account for more than 50% of the year. The role of pre-flowering fertilizer is to promote the development of flower organs, so that the spring shoots are more and more strong, which lays a good foundation for the next year's high yield. The pre-flowering fertilizer should be based on quick-acting phosphorus and potassium fertilizer, and then nitrogen fertilizer. After the physiological fruit drop, the fruit should be added once, and the fertilizer should not be applied with too much nitrogen fertilizer. From the prevention of the germination of the summer shoots, compound fertilizer and pig calf can be applied. In mid-August, combined with the autumn shoots, apply a strong fruit fertilizer. In the spring fruit development period, more calcium is needed, and calcium is lost in the land. It must be supplemented every year, especially in acid soil, and it can spray 2-5% calcium chloride during the young fruit stage and fruit expansion period. According to the county's red meat honey pomelo, the demand for magnesium is particularly large, 10 times more than citrus, and it can be sprayed with 0.5% magnesium sulfate in the green shoot or young fruit stage.