1缺氮油菜缺氮时,植株体内蛋白质合成受阻,叶绿素含量减少,花青素呈现,叶片先从老叶变红色,逐渐向新叶发展,叶片带黄色,长势弱,叶片瘦小;同时,植株矮小,分枝少,角果数和粒数减少,粒重减轻,产量显著下降。一般在苗期干旱脱肥易出现缺氮红叶。补救措施:每667m~2用7～8kg尿素或15～20kg 碳酸氢铵或20kg 人粪,对水浇施,既补充了氮肥,又缓解了旱情。2缺磷当土壤有效磷含量低于5mg/kg 时,植株就会表现缺磷症状;根系发育不良,生长慢而矮 Nitrogen deficiency rape lack of nitrogen, plant protein synthesis blocked, chlorophyll content decreased, anthocyanin rendering, the leaves from the old leaves turn red, and gradually to the new leaf development, leaves with yellow, weak growth, thin leaves; the same time, plants Shorter, less branched, reduced number of pods and grains, reduced grain weight, significantly reduced yield. Generally in the seedling drought prone to nitrogen deficiency leaves. Remedy: Each 667m ~ 2 with 7 ~ 8kg urea or 15 ~ 20kg ammonium bicarbonate or 20kg human waste, water facilities, both to add nitrogen, but also ease the drought. 2 Phosphorus deficiency When the soil available P content is less than 5 mg / kg, the plant will show signs of phosphorus deficiency; the root system is poorly developed and grows slowly but short