How many days the Urea can be absorbed after use?


The Summer is the big season for the fertilizer was applied to the field, especially the UREA. How many days the urea could be absorbed ? What are the factors that affect urea absorption? With the doubt, we contact the agronomist in China, and share the suggestion with you.

Urea is a molecular nitrogen fertilizer, crops can not be directly absorbed, Only can be absorbed as ammonium nitrogen fertilizer. So the Urea must be applied into soil, converted to ammonium carbonate in soil unease secreted by microorganisms .

The rate of urea transformation mainly depends on the amount and activity of urease, and urease is affected by many factors as follows:

First, soil acidity and alkalinity. urea in neutral soil transformation rate is higher than acid or alkaline soil; neutral environment is more suitable for microbial activity requirements.

Second. The fertility of soil, because the content of urease in fertile soil is higher than that in poor soil, therefore, the transformation rate of urea in fertile soil is faster.

Third: soil temperature. The soil temperature are more obvious to urea conversion. According to the data, when the soil temperature is 10 degrees centigrade, the total transformation of urea takes 7-10 days; 20 degree days need 4-5 days; if the soil temperature is 30 degrees centigrade, it only takes 2 days to complete the transformation.

Forth, soil moisture, soil moisture rich clay loam, urease hydrolysis is intense. According to the research, at 25-30 degree, The 70% moisture soil can come to the ammonization peak within one day and 28% urea can be absorbed as ammonium nitrogen fertilizer. On the other hand, the soil moisture deficiency of low water content, the conversion is lower.

In summary, according to the characteristics required soil fertilized urea conversion, in order to better play fertilizer, it should be based on specific conditions, suitably administered 3-6 days in advance, to enable timely absorbed by crops used for conversion of ammonium nitrogen.

Urea nitrogen 46%, is the most commonly used high quality nitrogen fertilizer, but the utilization rate of urea is usually only 45%-50% when it is applied to soil. In addition to the early application of urea, the following two methods are combined with higher fertilizer utilization:

1, deep urea. Whether for the base fertilizer or for top dressing, should be deep casing, fertilization depth of 10-12 cm is appropriate; urea deep can significantly improve the utilization rate. According to the test, urea application or shallow application of 2-3 cm, the utilization rate of only 30%; fertilization depth of 5 cm, the utilization rate of 45%; deep 10-20 cm, utilization rate of up to 65%.
2, mixed with urea. Urea and organic fertilizer, phosphorus and potassium fertilizer and trace element fertilizer with the application, can maintain the balance of soil nutrients, to maximize the nutrient utilization and play the role of fertilizer production.