Urea is a high concentration of nitrogen, quick acting fertilizer is neutral, can also be used to the production of a variety of complex fertilizer. Not residual any harmful substances in the soil, long-term application of no adverse effect. Animal husbandry can be used as ruminant animal feed. But in the granulation temperature is too high will produce a small amount of shrinkage of two urea, also called biuret, has inhibitory effect on crop. China fertilizer with urea shrinkage of two urea content should be less than 0.5%. Shrinkage of two urea content exceeds 1%, can't do a fertilizer, fertilizer and foliar fertilizer, urea content in other application periods also shoulds not be too much or too concentrated.

尿素是有机态氮肥，经过土壤中的脲酶作用，水解成碳酸铵或碳酸氢铵后，才能被作物吸收利用。因此，尿素要在作物的需肥期前4～8天施用。

Urea is organic nitrogen fertilizer, after urease process in the soil, hydrolyzed into ammonium carbonate or ammonium hydrogen carbonate, can be absorbed by crops. Therefore, the urea in crop fertilizer needed 4 to 8 days before the period of application.

施用：尿素适用于作基肥和追肥，有时也用作种肥。尿素在转化前是分子态的，不能被土壤吸附，应防止随水流失；转化后形成的氨也易挥发，所以尿素也要深施覆土。

Application: urea used as base fertilizer and top dressing, sometimes used as a fertilizer. Urea is a molecular state in the pre transition, not adsorption by soil, should prevent with water loss; transformation after the formation of ammonia and volatile, so the urea to deep fertilizing soil.

尿素适用于一切作物和所有土壤，可用作基肥和追肥，旱水田均能施用。由于尿素在土壤中转化可积累大量的铵离子，会导致PH升高2--3个单位，再加上尿素本身含有一定数量的缩二脲，其浓度在500ppm时，便会对作物幼根和幼芽起抑制作用，因此尿素不易用作种肥。

Urea is suitable for all the crops and all the soil, can be used as base fertilizer and top dressing, can use dry paddy field. Because of urea in the soil can be accumulated a lot of conversion of ammonium ions, will cause PH to increase 2--3 units, shrinkage of two urea plus urea itself contains a certain amount of, its concentration in the 500ppm, will have inhibitory effect on crop root and sprout, so is not easy to be used as a fertilizer and urea.