What are the precautions for using flush fertilization on vegetables?

Flush fertilization is a topdressing method that provides supplemental nutrients during the rapid growth period of crops. It is mainly used for topdressing during the vigorous growth season of vegetables and is widely used in greenhouse planting and open-field cultivation. Because flush fertilizer takes effect relatively quickly, generally showing results only a few days after application, flush fertilization has been widely adopted for many years. However, improper flush fertilization can cause vegetable growth problems, so we need to pay attention to some issues when applying flush fertilizer.

1. Correctly choose the type of flush fertilizer

There are many types of fertilizers, but not all fertilizers are suitable for flush application. Among nitrogen fertilizers, commonly used ones include urea, ammonia water, ammonium sulfate and ammonium nitrate; among potassium fertilizers there are potassium chloride, potassium sulfate or potassium nitrate. It should be noted that even water-soluble monoammonium phosphate and diammonium phosphate should not be applied by flushing, because phosphorus fertilizer has poor mobility after dissolving and is very easily fixed, and cannot leach into the soil layer with water. Therefore, the best application method for it is to apply it in layers into the soil, as only this can improve its fertilizer use efficiency.

2. The amount of flush fertilizer applied at one time should be kept minimal

The amount of flush fertilizer should also be controlled properly, and the amount must not be increased at will. In high-yield vegetable cultivation, the amount of pure nitrogen applied each time should be controlled at 2-3 kg per mu, and especially nitrate nitrogen must be controlled below 2-3 kg per mu; the amount of potassium fertilizer for a limited number of applications is generally controlled at 2-3 kg per mu. Otherwise, the waste and loss of nutrients will be relatively large, which not only reduces the use efficiency of nitrogen fertilizer but may also cause water pollution. Generally, 2 flush fertilizer applications per growing period are appropriate; too many will have adverse effects on the normal growth of vegetables.

3. Timing of flush fertilization

The timing of flush fertilization should be grasped properly. For example, fruit vegetables should be treated during the full fruit stage and after picking, while Chinese cabbage is suitable for treatment during the head-forming stage. In autumn vegetable cultivation, it is advisable to choose a time when the temperature has dropped, soil mineralization has declined, and the vegetables are in a period of massive growth.

4. Control of irrigation volume

Under border irrigation, avoid flood irrigation; when irrigating through channels, the ditch depth and water volume should be appropriate to prevent nutrients dissolved in the water from being lost with the water. Many farmers like this topdressing method, and using it well is very effective. However, if the pursuit is only for superficial results, without considering cost, and large amounts of nitrogen fertilizer are one-sidedly applied and flush fertilizer is abused, it will cause vegetable interplanting, decline in quality, reduced fertilizer use efficiency, and intensified soil salinization.

The above is an introduction to the precautions for using flush fertilization on vegetables. We hope it can help you. To learn more related knowledge, please keep following us.