Organic fertilizer is the main ingredient in grapefruit tree fertilization. Inorganic fertilizers are applied together. Organic fertilizers have long-lasting and stable effects, which can effectively improve the physical and chemical properties of the soil and enhance soil permeability. They have a very important role in improving the yield and quality of grapefruit.

1. Fertilization period of young trees

Young trees planted with grapefruit trees for 1-3 years are different from adult trees in cultivation. At this time, fertilization is mainly to cultivate strong root groups, promote new shoots, form crowns as soon as possible, and enter the fruiting period as soon as possible. Therefore, the young tree fertilization should be based on nitrogen fertilizer, appropriate application of phosphorus and potassium fertilizer.

2, The adult tree fertilization period

(1) Promoting bud strong flower fertilizer

The pre-flowering fertilizer is still dominated by nitrogen fertilizers, with appropriate amounts of potassium and phosphate fertilizers, and the amount of fertilization accounts for about 20% of the total annual fertilization.

(2) Fruit preserving fertilizer

This time fertilization needs to be mainly potassium and phosphorus, with a certain amount of nitrogen and magnesium. The amount of fertilizer applied during this period accounted for 5% -10% of the total amount of fertilizer applied throughout the year.

(3) Promoting fertility

In early and mid-July, re-applied organic fertilizer should be re-applied to lay a good nutritional foundation for flower bud differentiation. The amount of fertilizer applied at this time accounts for about 30% of the total amount of fertilizer applied throughout the year.

(4) Fruit picking

This time fertilization is mainly organic fertilizer, which can be combined with superphosphate, potassium sulfate and bone meal. The fertilization should be repeated and early, and early-maturing varieties should be applied in time after harvest, and late-maturing varieties should be applied before harvest.