棚（室）或露地栽培的韭菜有的经常发生黄叶干尖,或心叶、外叶褪绿后,叶尖开始变茶褐色,以后逐渐枯死,造成产品外观差、销售难、经济效益下降。据调查该病属于生理性病害,主要源自以下六个方面。（一）长期大量施用粪肥和硫酸铵、过磷酸钙等肥料,导致土壤酸化,造成酸性为害。（二）扣棚前施用大量碳酸氢铵,或在偏碱性土壤中使用硫酸铵,扣棚后地 Shed (room) or open-planted leeks often occur yellow tip dry tip, or heart leaves, outer leaves chlorotic, the tip began to turn brown, and then gradually dead, resulting in poor product appearance, sales difficult, the economic benefits decline. According to the investigation of the disease is a physiological disease, mainly from the following six aspects. (A) The long-term large-scale application of manure and ammonium sulfate, superphosphate and other fertilizers, resulting in soil acidification, resulting in acid damage. (B) buckle shed before the application of a large number of ammonium bicarbonate, or alkaline soil in the use of ammonium sulfate, after deducting shed