Urea is a nitrogen fertilizer with high nitrogen content, which is suitable for various soils and plants. It is easy to store, easy to use, and has little damage to the soil. It is a chemical nitrogen fertilizer that is currently used in a large amount. In industry, ammonia and carbon dioxide are used to synthesize urea under certain conditions.
The same aspect is that urea is all molecular nitrogen, which is not directly absorbed by crops, and can be absorbed in large quantities only after being converted into ammonium nitrogen in the soil. Therefore, regardless of the particle size of urea, the application of top dressing must be several days earlier than ammonium bicarbonate.
What should be paid attention to here is that urea granules of all sizes cannot be mixed with ammonium nitrate, sodium nitrate, ammonium bicarbonate and other highly hygroscopic fertilizers.
The difference is that the dissolution rate of large granular urea is slightly slower, and it is suitable for base fertilizer, but not for top dressing and flushing. Its particle size matches that of diammonium phosphate, and can be used as a material for blending compound fertilizers.
Small granular urea is suitable for various soils and various crops. It is a nitrogen fertilizer with high nitrogen content and can be used as base fertilizer and top dressing. When using small particles of urea as top dressing, it is best to apply it in strips or in acupuncture points, and try not to spread it.
If it cannot be applied in strips or holes, it is best to spray before and after light rain and when the soil is moist. Do not use too much when making green fertilizer, and apply enough when making tillering fertilizer and ear fertilizer. It also has a certain effect on increasing production when it is used as extra-root topdressing. Small granular urea is suitable for foliar fertilization, and its concentration is generally 0.5% to 2%.China Nitrogen Fertilizer suppliers