There are five common top dressing methods. Spreading method: Generally, it is sprayed directly between the rows of crops when the soil is moist. Irrigation with water: Mix fertilizer into the water and apply it around the root system of the crop with the water. Buried method: Dig pits between plants and rows, and apply fertilizer to the overburden. Mechanical work topdressing: Use automatic equipment and drip irrigation technology to irrigate the soil around the roots of the crop. Extra-root topdressing: mainly refers to foliar spraying.

One. Casting

1. It is usually carried out after the crops are watered or rained. The soil in the field is moist and cannot enter the field. You can directly spread fertilizer between the rows of crops.

2. This method is very convenient and simple. Its disadvantage is that it is easy to volatilize and lose nutrients, among which ammonium bicarbonate is more volatile.

3. Do not spray, ammonium sulfate, urea and potassium sulfate.

4. Although it can be applied, the operation is troublesome, and it is generally used when it is urgently needed.

Two. Irrigation with water

1. When the crop is watered, the fertilizer can be melted in the water and applied around the root system of the crop.

2. Advantages: The usage is relatively simple, saving time and effort, and does not require too much labor.

3. Disadvantages: It is easy to lose nutrients and cannot enter the deep layer of crop roots.

4. Generally used when the planting area is large, the fertilizer is sufficient and there is no labor force.

5. This method can be the first choice if the crop is severely lacking in fertilizer on a large area.

Three, buried method

1. Dig pits between rows and plants of crops, then apply fertilizer, and then cover the soil.

2. This method has higher fertilizer utilization rate and is the most economical, but it is more labor-intensive and labor-intensive.

3. Pay attention to the application. The ditch and pit for fertilization need to be kept at a distance of more than 10 cm from the roots and stems of the crop. If they are too close, the root system will be easily lost.

4. Because the fertilizer is concentrated and the concentration is large, it is not suitable to be used in the summer when the crop is growing and the water demand is large, and it cannot be used in the critical water demand period of the crop.

5. Generally, this method is applied in the winter slack season, when labor is sufficient and the demand for crop growth is not large.

6. Buried application is generally used at higher temperatures to avoid negative effects. After application, it must be watered in time to reduce fertilizer concentration.

Four. Follow-up on mechanical operations

1. In recent years, fertilization automation has gradually spread, and drip irrigation technology has begun to be widely used.

2. Operation method: install a fertilizer applicator at the place where the water source enters the drip irrigation main pipe, let the fertilizer dissolve in the fertilizer applicator, and put the drip irrigation main pipe into the suction pipe filter of the fertilizer applicator, so that the fertilizer can be automatically irrigated with water around the crop roots. In the soil.

3. This method of fertilization, the nutrients are not easy to volatilize, although the fertilizer is concentrated, but the concentration is small, which is safer, saves time and effort, and has a better effect.

4. The prospect of this fertilization method is better and more scientific, but the investment is too large, so it has not been promoted and applied in large-scale production.

Five, extra-root topdressing

1. Extra-root topdressing is actually foliar spraying. Under artificial planting, the growth environment of crops is better, and the crops grow faster, with more results, and higher yields.

2. In general, planting will be combined with spraying foliar fertilizer and topdressing to supplement the nutrients needed by the crop in time.

3. This method uses less dosage and has a faster fertilizer effect. It can also prevent the nutrients of the fertilizer from being fixed by the soil. It is a very economical and effective application method.