In agricultural production, it is inevitable to use chemical fertilizer to promote the normal growth and development of crops. So what should we pay attention to when using fertilizer?

1. Ammonium nitrate cannot be used on leafy vegetables

Cabbage, celery, water spinach and spinach have a short growth period, which can easily absorb nitrate ammonium and store it in the plant. If ammonium nitrate is applied, all the green leafy vegetables absorb nitrate ions. If they are eaten for a long time, it will easily cause cumulative poisoning.

2. Do not water after using urea

The nitrogen contained in urea is divided into amides. Under the function of urease secreted by soil microorganisms, amide nitrogen can be transformed into ammonium carbonate before it can be absorbed by vegetables or adsorbed and preserved by soil. For example, watering with urea will lead to loss. Therefore, whether urea is used as base fertilizer or topdressing, it needs to be fully transformed within 5 to 7 days after application, and then watering can avoid losses.

3. Ammonium sulfate cannot be applied multiple times

In the acidic soil or calcareous vegetable field, if ammonium sulfate is continuously applied for many times, the acidic soil will become more acidic and the calcareous soil will harden, which will seriously affect the normal growth of vegetables.

4. Ammonium bicarbonate cannot be applied when the vegetable field is lack of water

Ammonium bicarbonate is very unstable and easy to volatilize, especially when the vegetable field is dry and less water, resulting in greater losses. Therefore, if ammonium bicarbonate is applied to the vegetable field, whether as base fertilizer or topdressing, it needs to be deeply applied when the vegetable field is wet, and the soil needs to be overturned even after application. In case of dry weather, you can add water for sprinkling or watering after application.

5. Can not be a large amount of calcium

If phosphorus fertilizer is applied to the vegetable field for several consecutive years, too much phosphorus fertilizer will be supplied, which will be extremely unfavorable to the normal growth and development of vegetables, resulting in the early decline and wilting of vegetables, greatly reducing the yield and quality of crops. Under normal circumstances, it is best to apply an average of 15 kg to 20 kg per mu. For fruits and vegetables, you can appropriately increase the application.

6. Green leafy vegetables should not be sprayed with nitrogen fertilizer with high concentration

For example, if urea, ammonium sulfate and other solutions are sprayed on the leaves of crops, although it can make the tender leaves of vegetables fatter, look good in color and significantly increase the yield, nitrate may also accumulate in a large amount in the leaves of vegetables, which will pose a great threat to human health after we eat.