大棚菜施肥要防止肥害利用塑料大棚种植蔬菜时，施用化肥是一项有效的增产措施，但是施用不当，不但不能增产反而会造成肥害。因为大棚内一次施入较多的尿素、硫铵等氮肥时（尤其在叶面喷肥的情况下），遇到棚内高温，最易产生大量氨气。当棚内空气中氨含量达５ｐｐｍ时，... Greenhouse vegetable fertilizers to prevent fat damage Use plastic sheds to grow vegetables, the application of fertilizer is an effective stimulation measures, but the improper application, not only can not increase production but will cause fat. Because the greenhouse once applied more urea, ammonium sulfate and other nitrogen fertilizer (especially in the case of foliar fertilizer), encountered shed high temperature, most likely to produce large amounts of ammonia. When the shed air ammonia content of 5ppm, ...