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19几种常见肥料如何识别(1)尿素:尿素外观为白色,球状颗粒,总氮含量≥46.0%,容易吸湿,吸湿性介于硫酸铵与硝酸铵之间。尿素易溶于水和液氨中,纯尿素在常压下加热到接近熔点时,开始显现不稳定性,产生缩合反应,生成缩二脲,对作物失去肥效。如在炉子上放一块干净的铁片,将尿素颗粒放在上面,可见尿素很
19 Several common fertilizer how to identify (1) urea: urea appearance of white, spherical particles, total nitrogen content ≥ 46.0%, easy to absorb moisture, hygroscopicity between ammonium sulfate and ammonium nitrate. Urea is easily soluble in water and liquid ammonia. When pure urea is heated to near the melting point under normal pressure, instability begins to occur and a condensation reaction occurs to form biuret, which loses fertilizer effect on crops. If you put a piece of clean iron on the stove, the urea particles on it, we can see urea