According to the growth law of fruit trees, early application is advocated, and September-October is the best. At this time, high temperature, high humidity, fertilization is conducive to root healing and organic fertilizer maturation. The whole garden fertilization should be one meter away from the trunk, the depth of about 50 cm is better. The type of base fertilizer is based on farm fertilizer, the amount of fertilizer applied according to the production of 1 kg fruit 1.5-2 kg calculation, per mu usually apply 4000-5000 kg organic fertilizer, plus diammonium phosphate 40 kg, grass and wood ash 200 kg is appropriate. The method of fertilization varies from garden to garden. For dense garden, alternate rows of fertilization can be used. In the coming year, fertilization is not applied in the row, so as to save labor and effort.
The roots of apple trees are mainly distributed in the soil layer of 0-40 cm. The roots of apple trees have two peaks in the middle of the year and peak in autumn. The characteristics of apple tree fertilizer absorption are: nitrogen in early stage, potassium in middle and late stage, phosphorus absorption is relatively stable throughout the year. So fertilization should pay attention to the following points:
The fertilizer amount should be determined according to the yield load, and the fertilization ratio should be balanced. Apple's absorption ratio of nitrogen, phosphorus and potassium is 1∶0.5∶1. In general, nitrogen, phosphorus and potassium are 0.8kg, 0.4kg and 0.8kg per 100kg of fruit produced. According to China Agricultural resources network understanding autumn is the late growth of fruit trees, to mainly potassium fertilizer, promote fruit expansion and sugar accumulation, improve quality.
Time to apply fertilizer. Base fertilizer is applied in autumn when the root growth peak comes after fruit harvesting, and is applied in autumn when the shoot stops growing. In Beijing area, it is applied in September to October. This can not only ensure that fruit trees absorb fertility, but also prevent excessive growth of autumn shoots.
Combined application of organic fertilizer, chemical fertilizer and root fertilization. Organic manure is generally used as base manure, cow manure, chicken manure can be. The fertilization can be carried out by special orchard fertilizer, mostly fertilizer type fertilizer. In terms of the total amount of fertilization, the appropriate amount of cow and sheep manure should be "Jin Guo Jin fertilizer", and chicken manure can be halved. According to the total amount of fertilization in autumn, the fertilizer amount and fertilizer type should be supplemented in view of the shortage of fertilization in spring. Pay attention to the addition of nitrogen fertilizer, potassium dihydrogen phosphate and other root fertilizer according to the tree potential and current yield load.
Pay attention to the location and depth of the fertilizer. Generally, annular and semi-annular ditches apply to young trees. Ditch application, hole application, radiating ditch application and the whole garden application are mostly used for adult trees. The depth of fertilization is generally about 40 cm. With the enlargement of the crown, the scope and depth of fertilization should be increased correspondingly, and it is appropriate to apply the main distribution layer of the root.
Normally, fertilization can be combined with deep soil cultivation of orchards. Apple trees are different from field crops. The nutrients in the root soil of apple trees are not all due to years of absorption by the root system, and the soil is seriously hardened. The growth environment of the root system can be improved by deep turning and fertilization.