Urea is Nitrogen fertilizer
Physiologically neutral fertilizers do not leave any harmful substances in the soil and have no adverse effects on long-term application. However, when the temperature is too high in the granulation process, a small amount of biuret, also known as biuret, can inhibit the crop. China's urea biuret content of fertilizer should be less than 0.5%. When the content of biuret exceeds 1%, it cannot be used as seed fertilizer, seedling fertilizer and foliar fertilizer. Urea content in other application periods should not be too much or too concentrated.
Urea is an organic nitrogen fertilizer that can be absorbed and utilized by crops after it is hydrolyzed into ammonium carbonate or ammonium bicarbonate through the action of urease in the soil. Therefore, urea should be applied 4 to 8 days before the crop needs to be fertilized.
Application: Urea is suitable for basal and topdressing, and sometimes as a seed fertilizer. Before the transformation, urea is molecular and cannot be adsorbed by soil. It should be prevented from being lost with water. The ammonia formed after conversion is also volatile, so urea should also be deeply covered with soil.