How to apply nitrogen fertilizer to fruit trees

Excessive nitrogen in the fruit tree will cause imbalance between carbohydrates and nitrogen in the tree or imbalance between other elements, resulting in excessive vegetative growth, long leaves, poor flower bud differentiation, and serious fruit drop; summer and autumn fruit When the nitrogen content in the leaves exceeds 2.5% to 3.0% , the fruit ripening is delayed, the color of the fruit is poor, the flesh is coarse, the sugar content and the fruit hardness are lowered, the storage is not resistant, the physiological diseases are many, and the wintering ability of the tree is lowered.

 

The lack of nitrogen nutrition in fruit trees affects the photosynthesis and protein formation of fruit trees. The growth of the spring shoots of the trees is slow, the branches grow thin, and the leaves are thin and pale, which will cause the old leaves of the branches to become yellow and cause early autumn leaves. A lot of fruit drop. When nitrogen is deficient, the flower is small, the fruit setting rate is low, and the fruit color is poor. Long-term nitrogen deficiency will reduce the stress resistance of fruit trees and short tree life.

 

When fertilizing fruit trees, attention should be paid to maintaining the balance and coordination of various nutrients. Various nutrients have a promoting and restricting effect on each other. For example, phosphorus deficiency affects the metabolism of nitrogen-containing substances; potassium and nitrogen absorption and protein synthesis have a certain relationship. When applying nitrogen fertilizer, it is carried out simultaneously with phosphorus and potassium fertilizers, and the fertilization effect is good. .

 

The application of nitrogen fertilizer outside the roots has a significant effect. The application of nitrogen fertilizer to the roots before the germination of the fruit trees can improve the quality of the leaves and increase the photosynthesis intensity of the leaves. Spraying 0.3% urea on the foliar surface of the flowering period has a good effect on increasing the fruit setting rate. Spraying high concentration of urea on the foliage in late autumn can increase storage nutrition and beneficial fruit trees to grow and develop in the next year. After harvesting the fruit to 2 to 4 weeks before the defoliation , spraying the urea on the foliar surface not only helps the growth and development of the tree in the next year, but also increases the flowering rate, and also improves the fruit setting rate, so that the high yield of the tree is high. Therefore, we should pay attention to the application of nitrogen fertilizer in the late autumn.

 

Determination of the amount of nitrogen fertilizer: Because the growth period of the tree is different, the strength of the tree is different, the amount of nitrogen fertilizer needs to be different. Determine the amount of fertilizer to be adjusted according to the strength of the tree, adjust the ratio of nitrogen to phosphorus and potassium, and determine the application rate of nitrogen fertilizer.