Urea, also known as carbamide, is composed of carbon, nitrogen, oxygen, hydrogen organic compound is a white crystal, is currently the highest nitrogen content of nitrogen fertilizer. Urea contains high nitrogen content, application dosage should not be too large, so as to avoid unnecessary waste and “fertilizer damage”. Farmers in many fruit-producing areas use a lot of urea, resulting in dead trees, the consequences are very serious. Today we will introduce the proper use of urea.

Use urea ten taboo 

Mixed with ammonium bicarbonate

After urea is put into soil, it needs to 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. After ammonium bicarbonate was applied to the soil, the reaction was alkaline, and the pH value was 8.2 ~ 8.4. Farmland mixing ammonium bicarboate and urea, will make the conversion of urea into ammonia speed greatly slowed down, easy to cause urea loss and volatilization loss. Therefore, urea and ammonium bicarbonate should not be used in combination or simultaneously. 

Avoid surface broadcasting

Urea is spread on the ground and can only be used after 4-5 days of conversion at room temperature. Most nitrogen is easily volatilized in the ammonification process, and the actual utilization rate is only about 30%. If spread in alkaline soil and soil with high organic matter content, nitrogen loss will be faster and more. And urea shallow application, easy to be consumed by weeds. Urea is applied deep and melts the soil so that the fertilizer is in the moist soil layer, which is beneficial to the effect of fertilizer. The topdressing should be done at the side of the seedling with holes or trenches, and the depth should be about 10-15cm. In this way, urea is concentrated in the dense layer of the root system, which facilitates the absorption and utilization of crops. The experiment showed that the utilization rate of urea could be increased by 10% ~ 30%.

Three do not grow fertilizer

Urea in the production process, often produce a small amount of biuret, when the content of biuret more than 2% will be toxic to seeds and seedlings, such urea into seeds and seedlings, will make protein denaturation, affect the germination and seedling growth of seeds, so it is not suitable for planting fertilizer. If it must be used as seed fertilizer, avoid contact between seed and fertilizer and control the dosage.

Four avoid immediately after the irrigation

Urea belongs to amide nitrogen fertilizer, which needs to be converted into ammonia nitrogen to be absorbed and utilized by the root system of crops. Due to different soil quality, water and temperature conditions, the conversion process takes a long time or a short time. Generally, it can be completed after 2 ~ 10 days. Generally, irrigation should be done 2 ~ 3 days after application in summer and autumn, and 7 ~ 8 days after application in winter and spring.