The reason why large granules are more expensive than small ones for the same urea

The reason why large granules are more expensive than small ones for the same urea

At present, the urea sold on the market is divided into large granules and small granules. In terms of price, the price of large granules of urea is slightly higher than that of small granules of urea. Why should large granules of urea be sold a little more expensively? Is it better that large granular urea has higher quality and better fertilizer efficiency than small granular urea?

Generally speaking, urea with a particle diameter larger than 2 mm is called large granular urea. The difference in particle size stems from the difference in the granulation process and equipment used after the urea is produced in the factory. What are the similarities and differences between the application methods and fertilizer efficiency of large-granular urea and small-granule urea?

Similarities and differences in nature

The same between large and small granular urea is that their active ingredients are all water-soluble nitrogen molecules, and the nitrogen content is 46%. From the point of view of physics, the difference is that the particle size is different. Larger granules of urea have lower dust content than small granules of urea, higher compressive strength, good fluidity, can be transported in bulk, not easy to break and agglomerate, and are suitable for mechanized fertilization. This results in differences in application methods, fertilizer efficiency and price of different granular urea.

Application method

The same aspect is that urea is all molecular nitrogen, and the amount of them directly absorbed by crops is not large. It can only be absorbed in large quantities after being converted into ammonium nitrogen in the soil. Therefore, regardless of the particle size, urea should be applied a few days earlier than ammonium bicarbonate when applied as top dressing.

What should be paid attention here is that large and small granules of urea cannot be mixed with fertilizers with strong hygroscopicity such as ammonium nitrate, sodium nitrate and ammonium bicarbonate.

The difference is that the dissolving speed of large granular urea is slightly slower, which is suitable for basal fertilizer, but not for top-dressing and flushing fertilization. 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 granules of urea as top dressing, it is best to apply it in strips or holes, and try not to spread it. If it is not possible to apply in strips or in holes, it is best to apply before and after light rain and when the soil is moist. When used as greening fertilizer, the amount should not be too much, and when used as tiller fertilizer and ear fertilizer, it should be applied enough. It also has a certain effect of increasing production when it is used as top dressing outside the roots. Small granular urea should be used for foliar fertilization, and its concentration is generally 0.5% to 2%.

Fertilizer Efficiency Difference

Small granules of urea have a large surface area, and after application, the contact surface with water and soil is large, and the dissolution and release rate is slightly faster. The dissolution and release of large granular urea in the soil is slightly slower. In general, the difference between the speed of the two fertilizer efficiency is very small.

This is reflected in the application method, such as top dressing, 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-grained urea is smaller, and the content of large-grained urea biuret is low, which is beneficial to crops.

After reading these, you should understand the different characteristics of large and small granular urea! When choosing urea, whether to choose large granules or small granules should be determined according to the purpose of fertilization and the difference of crops.