Soil testing and Formula fertilization Technology of Chestnut

The main results are as follows: 1. The characteristics of fertilizer requirement: in the annual growth cycle, from the differentiation of male flowers in early spring to flowering and fruit setting, nitrogen was the most, followed by potassium, followed by phosphorus; from flowering to fruit expansion, phosphorus was the most, followed by nitrogen and potassium; from fruit expansion to harvest, potassium was needed the most, followed by nitrogen and phosphorus. In addition to nitrogen, phosphorus and potassium, chestnut trees also need appropriate amounts of calcium, magnesium and trace elements such as manganese, zinc and boron. If the supply is insufficient, poor leaf growth and high empty bract rate will occur. 2. Fertilization technology: under the medium fertility level, the amount of fertilizer applied per mu in the annual growth cycle of chestnut trees is 3000Mel 3500kg of organic fertilizer or 400Mel 450kg of commercial organic fertilizer, 16kg of nitrogen fertilizer, 7kg of phosphate fertilizer and 9kg of potash fertilizer. Organic fertilizer is used as base fertilizer, nitrogen and potassium are divided into base fertilizer and secondary topdressing, all phosphate fertilizer is applied, and chemical fertilizer and farm manure (or commercial organic fertilizer) are mixed. Base fertilizer: the base fertilizer is mainly organic fertilizer, combined with appropriate amount of chemical fertilizer. Farm manure 3000m / mu 3500kg or commercial organic fertilizer 400m / m 450kg, urea 5m / kg 6kg, diammonium phosphate 13m / kg 15kg, potassium sulfate 4m 5kg. Topdressing: topdressing in germination period: 13 kg / mu of urea and 6 kg of potassium sulfate. Topdressing during fruit expansion period: 10 kg per mu of urea and 4 kg of potassium sulfate. Extra-root topdressing: during the growing period from May to July, 0.05% manganese sulfate and 0.05% magnesium sulfate were sprayed to supplement trace elements. Spraying 0.1% Mel 0.2% borax solution in full bloom has a certain effect on solving the problem of chestnut shed, it only needs to be applied or sprayed once a year, and boron fertilizer should be used cautiously in dry years.