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　　Urea nitrogen content of 46.6%, the rural use more high quality of chemical fertilizer. Due to some farmers friend not quite understand the nature of urea, often exist in the process of application of many misconceptions. Specific performance in the following aspects:
　　1, with a mixture of producyion. Because of urea applied into the soil should be converted into ammonia can be absorbed by crops and after its transformation speed under alkaline conditions is much slower than under acid condition. And producyion applied into the soil after alkaline reaction, can make the conversion rate of urea significantly slow, easy to cause a loss of urea and volatile, and reduce the utilization rate of urea. Therefore, urea and producyion unfavorable to mix or applied at the same time.
　　2, surface broadcasting. Urea broadcasting in the earths surface, room temperature after 3 ~ 5 days of transformation can be absorbed by crops, most of the nitrogen in the process of urea ammonium into evaporate, utilization rate is only 30%, if the broadcasting in alkaline soil, nitrogen loss is more faster, so the farmer friend when applying urea does not to be surface broadcasting graph save trouble.
　　3, used as a seed manure. The urea in the process of production, often produce a small amount of biuret. Biuret content more than 2%, will produce poison to seeds and seedlings, affect the seed germination and seedling growth, severe cases can cause death.
　　4, after the water immediately. After is the amide nitrogen fertilizer, applied urea must be converted to ammonium nitrogen can be absorbed by crops. Transformation process due to soil, water and temperature conditions are different, such as length in each time, generally speaking, after 2 ~ 10 hours to complete. If the water immediately after use, and loss of urea are soluble in water.
　　5, with basic fertilizer mix. After urea application must be converted to ammonium nitrogen can be absorbed by crops. Ammonium nitrogen in alkaline conditions, most of nitrogen into ammonia volatilize, so, urea cant with lime, plant ash, calcium magnesium phosphate fertilizer and other basic fertilizer mix or used at the same time.
　　6, applied in celery. Celery throughout the growing season to topdressing of nitrogen fertilizer, but there is no application of urea. Because after the topdressing urea, can make the celery fibre increased coarsens, plant aging, slow growth, and to eat bitter, poor quality. Fertilize the celery appropriate USES producyion, ammonia and organic fertilizer, it is helpful to improve the quality.