Four common mistakes in urea use, pay attention when fertilizing

Urea is one of the most important chemical fertilizers for increasing crop yields, but at present farmers have many unreasonable practices in its application. These improper application methods not only cause a lot of unnecessary waste, but also seriously pollute the agricultural environment and groundwater resources. Therefore, the following four mistakes should be noted when using urea.

Mixing urea with ammonium bicarbonate

After urea is applied to the soil, it must be converted into ammonia before it can be absorbed by crops, and its conversion rate is much slower under alkaline conditions than under acidic conditions. Ammonium bicarbonate shows an alkaline reaction after being applied to the soil, with a pH of 8.2~8.4. Mixing ammonium bicarbonate and urea in farmland will greatly slow down the rate at which urea converts into ammonia, easily causing loss and volatilization loss of urea. Therefore, urea and ammonium bicarbonate should not be mixed or applied at the same time.

Surface broadcasting

When urea is broadcast on the surface, at room temperature it must go through a 4~5 day conversion process before it can be absorbed by crops, and most of the nitrogen is volatilized during the ammonification process, with a utilization rate of only about 30%. If it is broadcast on alkaline soil and soil with high organic matter content, nitrogen loss is faster and greater. Therefore, nitrogen should not be broadcast on the surface.

Using urea as seed fertilizer

During the production process of urea, a small amount of biuret is often produced. If the biuret content exceeds 2%, it will be toxic to seeds and seedlings. When urea enters seeds and seedlings, it will denature proteins and affect seed germination and seedling growth.

Irrigating immediately after applying urea

Urea is an amide nitrogen fertilizer, and after application it must be converted into ammoniacal nitrogen before it can be absorbed and utilized by crops. The conversion process varies in duration depending on soil quality, moisture, temperature and other conditions, and generally takes 2~10 days to complete. If urea is irrigated or drained immediately after application, or applied before heavy rain in dryland, the urea will dissolve in water and be lost.