What to pay attention to when applying urea
1. Try to avoid using it alone. The ideal application method is to first apply organic fertilizer, and then apply urea, superphosphate, potassium chloride and other fertilizers in a reasonable formula.
2. Urea cannot be mixed with ammonium bicarbonate. The mixed application of ammonium bicarbonate and urea will greatly slow down the conversion rate of urea into ammonia, which is easy to cause urea loss and volatilization loss.
3. Urea cannot be immediately irrigated after application of urea. Urea is an amide nitrogen fertilizer that must be converted into ammonia nitrogen after application in order to be absorbed and utilized by crops. If applied immediately after watering or before heavy rain, urea will be lost.
How to Apply Urea without Waste
1. Determine the amount of topdressing based on soil fertility. Practice has shown that increasing the amount of fertilizer applied to mid to low yield fields can significantly increase yield. For high-yield fields, it is sufficient to maintain a general level of fertilization.
2. Top dressing during the peak nutritional period of crops. The key to improving the utilization rate of topdressing fertilizers is to grasp the critical period and greater efficiency period of nutrient absorption by various crops, and try to topdressing during the nutrient peak period of crops in order to improve the utilization rate of fertilizers.
3. Urea needs to be deeply applied to the soil. When applying urea to dry field crops, it is recommended to dig pits or dig trenches with a depth of less than 10 centimeters to keep the urea in moist soil, which is conducive to the conversion of urea and the adsorption of ammonia fertilizer by the soil, reducing volatilization losses.
4. Urea should be applied in advance. Because urea is a low molecular organic compound, there must be an ammonification process after it is applied to the soil, transforming it into a highly volatile ammonium carbonate before it can be absorbed by crop roots. Therefore, when topdressing crops with urea, it should be applied about 7 days earlier than other nitrogen fertilizers.
5. Urea cannot be mixed with alkaline fertilizers. Urea belongs to neutral fertilizers, and should not be mixed with alkaline fertilizers when topdressing to prevent reducing fertilizer efficiency. If it cannot be mixed with alkaline fertilizers, the fertilization dates should also be staggered, usually every 3-5 days.
6. Urea should be used as root dressing. Urea has less damage to crop leaves, is easily soluble in water, has strong diffusion, is easily absorbed by the leaves, and is not easy to cause wall separation after entering the leaves, making it suitable for topdressing outside the roots. But high-quality urea with a biuret content not exceeding 2% should be selected to prevent damage to the leaves.
