How to apply nitrogen fertilizer to fruit trees

Nitrogen is the constituent of protein, the basis of production, and the material basis for yield formation. The low nitrogen content of fruit trees, although able to flower, but the fruit setting rate is low, the fruit is small, the fruit color is light and poor, and the yield is low. Long-term nitrogen deficiency will lead to weakened stress resistance and shortened life span of fruit trees; fruit trees have high nitrogen content, although fruit Large, but branches and leaves long, flower buds poorly differentiated, serious drop and fruit drop, if the nitrogen content in the leaves of fruit trees in summer and autumn more than 2.5%, the fruit is delayed ripening, poor coloring, thick meat, reduced sugar content and hardness, intolerant storage, physiological There are many diseases and it is not safe for winter.

Nitrogen is supplied during the rainy season. From June to July in the rainy season, especially in orchards with poor fertility, nitrogen fertilizers are leaching severely with rainfall, which may cause nitrogen deficiency and lead to premature decline or premature fall of the functional leaves. Therefore, it is necessary to ensure that the nitrogen supply in the rainy season is constantly on the line.

The application of nitrogen fertilizer in the spring was invalid for flowering and fruit setting in the year. Nitrogen is generally in the form of two forms of nitrate nitrogen and ammonium nitrogen. Ammonium nitrogen and nitrate nitrogen are converted into nitrogen dioxide after entering the fruit tree body, and they are combined with carbohydrates to form amino acids and stored in the tree body. Although the time of this transformation process is not yet clear, it certainly takes a long time. What is required for flowering and fruit setting of fruit trees is the nitrogen already stored in the tree body in the form of amino acids. Therefore, nitrogen supplementation in fruit trees should be followed by the application of base fertilizer (from late August to early September, mainly organic fertilizer, combined with phosphorus and potassium fertilizers). After harvesting, topdressing nitrogen fertilizer or foliar application of high nitrogen fertilizer 1 or 2 times should be applied. (In the principle of not causing fertilizer damage), rather than spring nitrogen.