First, it should not be mixed with alkaline fertilizers or applied at the same time
Urea must be converted into ammonia nitrogen after application will produce fertilizer effect, while ammonia nitrogen in alkaline conditions, most of the nitrogen will become volatile ammonia, so urea can not be alkaline with lime, plant ash, calcium magnesium phosphate, etc. Fertilizers are mixed or applied simultaneously. In general, in summer and autumn, urea and alkaline fertilizers should be staggered for 3 to 4 days, and winter and spring should be staggered for 7 to 8 days.
Second, it is not suitable for seed dressing
In the production process of urea, a small amount of biuret is often produced. When the content of biuret exceeds 2%, the seeds and seedlings will be poisoned. Such urea enters seeds and seedlings and denatures the protein, affecting seed germination and Seedling growth.
Third, it should not apply immediately after irrigation
Urea is an amide nitrogen fertilizer, which needs to be converted into ammonia nitrogen to be absorbed and utilized by the crop roots. The conversion process depends on the conditions of soil quality, moisture, and temperature, and the time varies from time to time. Generally, it takes 2 to 10 days to complete. Immediately after irrigation or dry land is applied before heavy rain, urea will be dissolved in water and lost. Generally summer and autumn should be 2 to 3 days after application to irrigation, winter and spring season should be watered after 7 to 8 days after application.
Fourth, not suitable for surface application
Urea is applied to the surface of the earth and it can be used after 4 to 5 days of conversion at room temperature. Most of the nitrogen is easily volatilized during the ammoniation process. Generally, the actual utilization rate is only about 30% if it is in alkaline soil and organic matter content. Spreading in high soil, nitrogen loss will be faster and more. And shallow urea, easily consumed by weeds. Deep application of urea, melting of fertilizer in soil, fertilizer in a moist soil, is conducive to the exertion of fertilizer efficiency. As a topdressing fertilizer, apply to seedlings or ditching on the seedling side. The depth should be 10 to 15 cm. Tests have shown that urea is applied deep in the root-dense layer to facilitate crop absorption and utilization, and can improve utilization by 10% to 30% compared with shallow application.
Fifth, it should not be used excessively
Urea has a high nitrogen content, generally 5-15 kg per mu, and 15-20 kg per mu. Excessive application can not be absorbed by the soil before it is converted to ammonium bicarbonate. On the one hand, it is easily leached by rainwater and injure crops. On the other hand, it will enter groundwater, causing nitrogen pollution in the water, causing nitrite deposition, and seriously affecting humans and animals. Safety.
6. It is not appropriate to apply high-concentration foliar sprays in all nitrogenous fertilizers. Urea is the most ideal foliar fertilizer. When urea is sprayed, the amount and rate of protein synthesis in the crop exceed those of other nitrogen fertilizers. However, when foliar spraying, avoid urea solution concentration is too large, otherwise it will burn the leaves and poison plants.
Seven, it should not be used too late
The application of urea too late is not conducive to the exertion of the fertilizer effect, and it is easy to cause the crop to become greedy green later, so it should generally be applied 4 to 7 days earlier than other nitrogen fertilizers.
Cleaner Products,Toilet Bowl Cleaner Liquid,Toilet Block Cleaner,Stain Remover Cleaning
Wuxi Keni Daily Cosmetics Co.,Ltd , https://www.kenidailycosmetics.com