1. It is not advisable to water immediately after urea is applied
After urea is applied, it will be dissolved by water. Because the adsorption between soil colloid and urea is very weak, the fluidity of urea in the soil is strong, especially the flooding water will cause the urea to drip deep into the layer,lower fertilizer effect. Therefore, it is not advisable to water immediately after the application of urea. It is unscientific to apply urea before the rain.
2. Urea is not directly used as a seed fertilizer. Because urea contains a small amount of biuret, generally less than 2%, biuret is harmful to seed germination and growth. If it has to be used as seed fertilizer, the seed and urea can be separated from the ground, and donot use urea to soak or dress seeds.
3. After urea is converted into ammonium bicarbonate, it is easy to decompose and volatilize on calcareous soil, resulting in nitrogen loss. Therefore urea should be applied depth after application.