冬季小麦常因管理不善、遇到不良的环境条件、缺乏某种营养元素而出现黄苗,其中又以缺素型发黄较为常见。缺氮型发黄小麦缺氮植株矮小细弱,分蘖少而弱,幼苗叶片进而发黄、叶尖枯萎,叶下部老叶发黄枯落。其原因一般是播种过早、沙性田、基肥施得不足而分蘖肥施得不及时,且用肥量 Winter wheat often due to poor management, encountered adverse environmental conditions, the lack of a nutrient element and the emergence of yellow seedlings, of which the lack of prime yellow is more common. Nitrogen deficiency yellow wheat lack of nitrogen plants short and thin, less and less tiller, seedling leaves and then yellow, withered leaves, yellow leaves below the old leaves. The reason is generally sowing too early, sand field, base fertilizer inadequate and tillering fertilizer is not implemented in time, and the amount of fertilizer