As a common fertilizer, urea has always attracted the attention of all parties. Urea currently has large particles and small particles on the market. What are the differences between large-particle urea and small-particle urea in addition to their particle size?

      Urea Generally speaking, urea with a particle diameter of more than 2 mm is called large-particle urea. The active ingredients of the granules are water soluble urea molecules, and the nitrogen content is 46%. From the physics point of view, the only difference is the size of the particles. The difference in the size of urea granules stems from the difference between the granulation process and the equipment after urea is produced in the factory.

1. From the price point of view, the price of large urea is slightly higher than that of small urea.

2. Large-granule urea is relatively low content of small urea dust, high compressive strength, good fluidity, can be bulk transport, not easily broken and agglomerated, suitable for mechanized fertilization.

3, large particles of urea than the surface is relatively small, slower dissolution rate after application into the soil, combined with a larger single-grain weight, can be immersed in deeper soil under the application of paddy field, reducing volatilization losses.

      The International Fertilizer Development Center has systematically concluded that large-grained urea, as the base fertilizer and deep application of rice, has significant agronomic and economic advantages through extensive field trials of tropical and subtropical rice, and can improve nitrogen fertilizer utilization efficiency. At the same time, it is believed that the deep application of large urea in paddy fields can reduce N2O emissions from greenhouse gases. The main reason is that the release rate of mineral nitrogen is slowed down, which reduces the occurrence of denitrification. Among them, many tests used urea with a large particle size of 7 mm or more. The application method is to apply 7 cm deep in the middle of 4-hole rice by hand or mechanically during rice transplanting. The data shows that the nitrogen fertilizer utilization rate of large grain urea application in rice can be as high as 65%, while the utilization rate of ordinary urea (particle size 1.5 mm) application is only about 32%. The main reason for the test was to reduce the loss of ammonia volatilization. Some domestic units have also conducted local tests on cotton fields, rice and Chinese cabbage. The results show that the trend of increasing the production of large-particle urea is smaller than that of small-particle urea.

      Comparing the fertilizer efficiency tests of large-particle urea and ordinary small-particle urea on cotton, the results of increasing yield of large-particle urea on cotton show that the application of large-particle urea is superior to small-particle urea in the economical character, yield and output value of cotton. At the same time, it can promote the stability of cotton, prevent premature aging of cotton, and reduce the rate of cotton bud loss.

4. Due to the different urine concentration requirements of the processing technology, the biuret content of the large urea product is generally reduced, which is beneficial to crops.