It is important to apply "Yuezi fertilizer" after fruit harvest.

Base fertilizer application in autumn can increase the stored nutrition of fruit trees, promote the health of trees and flowering in the following year, set fruits, young fruit cell formation, strong growth of new shoots, early formation of leaf area, shorten the nutrient conversion period, and enter the physiological differentiation of flower buds as soon as possible. It is the most important and critical fertilization. Do not be careless and take it lightly. Fruit farmers vividly call autumn fertilization "confinement fertilizer", just like a woman pregnant for October, once childbirth, physical and mental fatigue, nutrition exhaustion, must timely supplement a large number of nutrients, in order to ensure the health of mother and child.

Fruit trees after the late expansion of fruit, after harvesting tree nutrition consumption has been empty. Especially for late-ripening apples, if sufficient basal fertilizer is not applied in time after harvest, the tree storage nutrition is seriously deficient, not only winter and spring will cause rot disease reproduction disaster, but also seriously affect the flowering, fruit setting and young fruit cell formation in the next year, which will cause weak inflorescence, low fruit setting rate, small young fruit size, thin shoots and small leaves, and prolong the nutrient conversion period.

Base fertilizer is the most basic and important fertilizer in orchard, which relates to the supply of various nutrients in the annual cycle of fruit trees. Autumn basal fertilizer should pay attention to timing, rationality and scientificity. Fertilization time is generally in September-October, apple demand for nitrogen, phosphorus and potassium nutrients is proportional requirements, at the same time should also increase the application of organic fertilizer, supplement appropriate trace elements; fertilization method for furrow application or hole application; fertilization position, in the outer edge of the tree crown inner; fertilization depth, generally in 20-40 cm root concentrated distribution layer. Root application requires that under the projection of the crown periphery, a trench should be dug for shallow application. Generally, the trench length is 150~200cm, the width is about 40cm, and the depth is 40cm. Compared with spring and winter, autumn fertilization can increase fruit setting rate by 8-10%, yield by 10-15%, and the effect of yield increase and quality improvement is very obvious.

Autumn fertilization has other benefits.

First of all, the nutrients consumed by fruit trees from early spring germination to flowering and fruiting are mainly the nutrients stored in the trees of the previous year. The best time for nutrient accumulation was from harvest to defoliation, and basal fertilizer application in autumn could increase the nutrient reserve of trees.

Secondly, autumn is the last growth peak of roots in a year, its life activity is vigorous, its ability to absorb nutrients is strong, and it is beneficial to delay leaf senescence, enhance photosynthetic capacity of autumn leaves and increase nutrient storage of trees.

Moreover, autumn soil temperature is higher, moisture content is better, conducive to soil microbial activities. The organic fertilizer decomposed quickly and was easily absorbed and utilized by roots. Studies have shown that autumn fertilization can increase the fertilizer efficiency of nitrogen, phosphorus, potassium, calcium and magnesium by 1, 5, 3, 2 and 2 times respectively.

Finally, autumn fertilization can improve the root growth environment and enhance the resistance of trees. Combined with fertilization and deep ploughing in autumn, it can optimize soil structure, improve soil permeability conditions, facilitate root respiration and growth, and improve soil water storage, fertilizer conservation and winter resistance.

Therefore, autumn base fertilizer, winter base fertilizer, spring base fertilizer, from the purchase of fertilizer to fertilization, are the same money and labor pay, but the fertilizer effect received is completely different.

Therefore, many experts and professors appeal: fruit trees, autumn base fertilizer is "gold", winter base fertilizer is "silver", spring base fertilizer is "broken copper rotten iron". The majority of fruit farmers friends should fully understand the important meaning.（