As a commonly used fertilizer, urea has been concerned about its development. At present, urea on the market is divided into large particles and small particles. Generally speaking, urea with a particle diameter greater than 2mm is called large granular urea. The difference in particle size is due to the difference in granulation process and equipment after urea production in the factory. What is the difference between large granular urea and small granular urea?
First, the similarities between large and small granular urea are that their active ingredient is a water-soluble fast-acting urea molecule with a nitrogen content of 46%. From a physics point of view, the only difference is the particle size. Large-grained urea has low dust content, high compressive strength, good fluidity, can be transported in bulk, is not easy to break and agglomerate, and is suitable for mechanized fertilization.
Secondly, from the perspective of fertilization, the surface area of small urea particles is larger, the contact surface with water and soil is larger after application, and the dissolution and release speed is faster. The dissolution and release rate of large particle urea in the soil is slightly slower. In general, there is little difference in fertilizer effectiveness between the two.
This difference is reflected in the method of application. For example, in the process of topdressing, the fertilizer effect of small granular urea is slightly faster than that of large granular urea. From the perspective of loss, the loss of large granular urea is less than that of small granular urea, and the content of diurea in large granular urea is lower, which is beneficial to crops.
On the other hand, for the absorption and utilization of crops, urea is molecular nitrogen, which is directly absorbed by crops in a small amount, and can only be absorbed in large quantities after being converted into ammonium nitrogen in the soil. Therefore, regardless of the size of urea, topdressing is several days earlier than ammonium bicarbonate. In addition, the particle size of large granular urea is similar to that of diammonium phosphate, so large granular urea can be mixed with diammonium phosphate as a base fertilizer, and it is best not to use large granular urea for top dressing.
The dissolution rate of large granular urea is slightly slower, which is suitable for base fertilizer, not for topdressing and flushing fertilization. Its particle size matches that of diammonium phosphate and can be used as a material for mixed compound fertilizers. It should be noted here that large granular urea cannot be mixed with ammonium nitrate, sodium nitrate, ammonium bicarbonate and other hygroscopic fertilizers.
Through the fertilizer test of large granular urea and ordinary small granular urea on cotton, the production effect of large granular urea on cotton shows that the economic characteristics, yield and output value of large granular urea are better than small granular urea, which can promote the stable growth of cotton and prevent Premature aging of cotton reduces the shedding rate of cotton buds.
Post time: Jul-20-2023