Urea is a high concentration of fast nitrogen fertilizer containing 46% pure nitrogen. With high nitrogen efficiency characteristics, so by the farmers favorite. Top dressing is in the rapid growth stage of crop growth period, that is, vegetative growth and reproductive growth at the same time into a large number of growth and development period, to crop a certain amount of quick-acting nitrogen or nitrogen and potassium fertilizers to meet the needs of high yield crops. At this time it is the crop nutrient demand, Urea the root absorption efficiency is high, the topdressing with nitrogen fertilizer utilization rate of up to 50% or more, the nutrients in the fertilizer can be a lot of rapid flowering fruit is the result of absorption and utilization, and timely into Yield. Therefore, for the fertilizer fertilizer varieties must have easy to dissolve and quick effect characteristics, Urea and urea is often the preferred fertilizer for farmers as fertilizer, that it has a high nitrogen content and quick effect.
Urea is one of the most important varieties of nitrogen fertilizers. Now the main features of urea are described below:
1. Urea is a high concentration of acylamide nitrogen fertilizer, Urea nitrogen fertilizer is the highest nitrogen content of fertilizer, quasi-nitrogen content of 46%.
2. Ordinary urea is white crystal, was needle or prismatic crystal, hygroscopicity strong. The agricultural urea fertilizer is mostly granular, is a plus a moisture-proof agent made of translucent particles. Domestic urea generally particle size of 0.8 to 2.5 mm, imported urea particle size 2 to 4 mm, Urea the largest in more than 7 mm.
3. Urea in the water can quickly melt, touch easily soluble, no creamy feeling.
4. Urea tasteless and odorless. Urea If the smell of urea can smell, may be mixed with ammonium bicarbonate; urea burning smoke, no smell. If you smell the smell of burning, may be mixed with ammonium chloride.
5. Urea is a neutral quick-acting fertilizer, Urea applied to the soil through the urease catalytic role after a few days, into ammonium carbonate or ammonium bicarbonate can be absorbed by the crop. Field application of urea, generally 3 to 4 days in summer effective, 7 days or so fall effective.
6. urea as a base fertilizer to deep cover soil. Urea in the conversion before the molecular state, can not be soil adsorption; conversion of ammonia after the formation of volatile. So to deepen, and to prevent the loss of water.
7. Urea for topdressing to be deep, and should not immediately irrigation, Urea if immediately irrigation easy to make the loss of urea with water, Urea should be interval 4-6 days after irrigation. Chase fertilizer time should be in the morning or evening.
8. urea for fertilizer should be careful not to direct contact with the seeds, because the high concentration of urea directly contact with the seeds, often affect the seed germination, resulting in missing seedlings.
9. urea in the biuret content of more than 1% can not do fertilizer, Urea fertilizer and foliar fertilizer. Because urea in the production of granulation, often due to high temperature produce a small amount of biuret, also known as biuret, the crop has an inhibitory effect. So the field of urea, the amount should not be too large or too concentrated use.
10. Urea is a physiological neutral fertilizer, Urea in the soil does not leave any harmful substances, long-term use without adverse effects.
11. Urea should be stored correctly. Such as improper storage, easy to moisture caking, affecting the original quality of urea, to bring some economic losses to farmers. Before use must keep the urea bag intact, the transport process to gently, rain. Store in a dry, well ventilated place where the temperature is below 20 degrees. Has opened the bag of urea, such as not used up, be sure to timely closure of the pocket, to facilitate the use of the next year.