1. The leaves of citrus trees are curly, mainly because the root system is weak and can't absorb enough nutrients (especially trace elements such as boron, zinc, molybdenum, iron and manganese) to meet the needs of plant growth and development.

2. To apply deep and heavy organic fertilizer to improve the soil, so that the soil layer is deep, the soil is loose, the soil is fertile, the root system is deep, developed root groups are cultivated, the absorption capacity is enhanced, and sufficient and comprehensive nutrients are absorbed to meet the needs of the growth and development of the aboveground parts, so that the aboveground parts can flourish, the leaves are dark green and there is no leaf curling phenomenon.

3. In addition, fertilization management should be strengthened. In the bud stage of new shoots, nitrogen, phosphorus and potassium (20~20~20) water-soluble fertilizer and amino acid compound micro-fertilizer should be applied to the roots once in time, and the mixed solution of magnesium sulfate, zinc sulfate, borax, urea, potassium dihydrogen phosphate and amino acid compound micro-fertilizer should be sprayed on the leaves for 2~3 times every 7~ 10 days to promote plant growth.