Urea should be applied deeply. This is not only conducive to the conversion of urea, but also can reduce the volatilization loss after urea is converted to ammonium carbonate. The application should not be too close to the root system to prevent ammonia damage to burning seedlings.
2. When urea is used as top dressing of rice, considering the characteristics of initial fluidity, do not irrigate immediately after application, and then irrigate after a few days when it is converted into ammonia nitrogen.
3. Do not overuse urea at one time to cause loss on sandy soil. It is advisable to apply it flexibly based on the principle of "eat less, eat more meals".
4. Use it earlier than other nitrogen fertilizers. Because urea is a low-molecular-weight organic compound, it must undergo an ammonification process after it is applied to the soil, and it can be converted into a highly volatile ammonium carbonate before it can be absorbed by the roots of the crop. Therefore, when using urea as top dressing, it should be It is applied about 7 days earlier than other nitrogen fertilizers.
5. Do not mix with alkaline fertilizers. Because urea is a neutral fertilizer, if it is mixed with alkaline fertilizers, it is easy to reduce fertilizer efficiency. Such as alternate application, also staggered 3-5 days.
6. It is not advisable to irrigate immediately after fertilization. After urea is applied to the soil, it cannot be absorbed by the soil before it is decomposed and transformed. If you irrigate water immediately after top dressing, it will cause a large loss of urea. The soil is seriously lacking in water. When irrigation is necessary, small water should be used frequently, and flooding should not be avoided.