How does urea fertilize well

The methods of urea fertilization with good effect are as follows：

1. Balanced fertilization.Urea is a pure nitrogen fertilizer and does not contain phosphorus and potassium in a large number of elements necessary for crop growth. Therefore, when making top dressing, formula fertilization technology should be used on the basis of soil measurement and laboratory tests to balance the application of nitrogen, phosphorus and potassium fertilizers. Only the reasonable combination and scientific application of nitrogen, phosphorus and potassium fertilizers can improve the utilization rate of follow-up urea.

2. Timely implementation.When urea is used as top dressing, it should be applied 1 week before the critical nitrogen demand period and the greater efficiency period of the crop.Different crops have different critical periods of fertilizer demand and greater efficiency periods, so they should be treated differently and used rationally.

3. Top dressing in time.Urea is an amide fertilizer, which needs to be converted into ammonium carbonate to be adsorbed by soil colloids and then absorbed by crops. This process takes 6 to 7 days. Therefore, when urea is used as top dressing, it should be applied about 1 week before the critical nitrogen demand period of the crop and the greater efficiency period of the fertilizer. , Not too early or too late.

4. Deep application of soil cover.For application on crops such as corn, wheat, tomatoes, cabbage, etc., a hole 15 to 20 cm deep should be dug 20 cm away from the crop, the fertilizer should be applied and the soil should be tightly covered, and the soil should be watered after 7 days if the soil is not too dry.When the soil is severely drought-stricken and needs watering, it should be lightly watered once with small water, and not overflowed with large water to prevent urea from flowing with the water.

5. Foliar spraying.Urea is soluble in water, has strong diffusion, is easily absorbed by the leaves, and has little damage to the leaves. It is suitable for top dressing outside the roots and can be combined with crop pest control for foliar spraying.However, when making top dressing outside the roots, urea with a diuret content of not more than 2% should be selected to prevent damage to the leaves.The spraying time should be after 4 pm. At this time, the transpiration volume is small and the leaf pores gradually open, which is conducive to the full absorption of the aqueous urea solution by the crop.