The key is to supplement boron and zinc after production of Chinese chestnut.

Foliar spray. As an auxiliary measure of soil fertilization, it has many advantages, such as simple method, less fertilizer, fast effect, high utilization rate, not affected by tree nutrient redistribution and so on. 0.2% borax plus 0.2% zinc sulfate combined with 600 times solution of new high lipid membrane is often used for foliar spraying. The time should be in the morning when the dew is not dry or in the evening, moist and windless weather is better.

After fruit harvest, in the crown drip line, where the fibrous roots are most distributed, dig a ditch with a length of 1 m, a width of 0.4 m and a depth of 0.6 m, apply boron and zinc micro-fertilizer and other organic fertilizers, and then cover the soil. The amount of boron and zinc application is calculated according to the size of the crown, 10-20 grams of boron and zinc per square meter. For fruiting trees, 100 grams of borax and zinc sulfate can be applied. The application of boron and zinc fertilizer in soil has obvious effect within five years.