化肥若施用不当则会发生毒副作用,既浪费肥料,又可能影响人体健康,生产实践证明,蔬菜施化肥应做到“六忌”: 一忌叶类蔬菜施硝铵小白菜、大白菜、苋菜、空心菜、芹菜、菠菜、包心菜等,生长期中易吸收硝酸态氮肥,如施用硝铵,绿叶蔬菜吸收的都是硝酸盐类离子,人食用后盐类进入人体,久而久之易累积中毒。二忌施尿素后浇水尿素中所含氮成分为酰铵,酰铵态氮素在土壤微生物分泌的脲酶作用下,转化为碳酸铵或碳酸氢铵才为蔬菜根系吸收利用。如尿素施后马上浇水或遇到雨淋,酰铵态的氮素就会流失。所以,尿素无论作蔬菜基肥或追肥,都应施后经过5-7天,使其全部转化后再浇水,以免造成损失。三忌反复施用硫铵在酸性土壤或石灰性菜田中,若连续多次施用硫 If the improper application of fertilizers will have toxic side effects, both waste of fertilizers, but also may affect human health, production practices have proved that the application of chemical fertilizers should be done “six bogey”: a bogey leafy vegetables nitronium Chinese cabbage, Chinese cabbage , Amaranth, spinach, celery, spinach, cabbage, etc., easy to absorb nitrate nitrogen during growth, such as the application of ammonium nitrate, green leafy vegetables are absorbed nitrate ions, salt into the human body after eating, over time accumulated poisoning. Second, avoid the use of urea water after urea nitrogen contained in the composition of ammonium acylate, ammonium nitrogen in the soil microorganisms in the secretion of urease, into ammonium carbonate or ammonium bicarbonate for vegetable root absorption and utilization. Such as urea water immediately after application or encounter rain, ammonium nitrogen will be lost. Therefore, whether urea or top-dressing for vegetables, should be applied after 5-7 days after all the transformation and then watering, so as to avoid loss. Three bogey repeated application of ammonium sulfate in acid soil or calcareous vegetable fields, if the continuous application of sulfur