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对冬季农作物施用氮素化肥,一般用碳铵比尿素好。这是因为: 尿素是一种酰胺态氮肥,施入土壤后作物不能直接吸收,只有在土壤微生物分泌的脲酶作用下,经过较长时间才被转化为铵态氮,水解成碳酸铵或碳酸氢铵才能发挥肥效。由于冬季温度低,这种转化过程十分缓慢,一般需要10天以上。据试验,土壤温度在20℃时,完成转化需要4～5天;土温在10℃时,完成转化则需7～10天。即温度越低,尿素的转化过程就越
Nitrogen fertilizer applied to winter crops, ammonium bicarbonate is generally better than urea. This is because: urea is an amide nitrogen fertilizer, the soil can not be directly absorbed into the soil, and only under the action of urease secreted by soil microorganisms, after a long time was converted to ammonium nitrogen, hydrolysis into ammonium carbonate or bicarbonate Ammonia can play fertilizer effect. Due to the low winter temperatures, this conversion process is very slow, generally takes more than 10 days. According to the experiment, when the soil temperature is 20 ℃, it takes 4 ~ 5 days to complete the transformation. When the soil temperature is 10 ℃, it takes 7 ~ 10 days to complete the transformation. That is, the lower the temperature, the more urea is converted