1、氮素缺乏症菜豆缺氮表现为植株长势弱,叶片薄且瘦小,新叶叶色淡绿,老叶叶片黄化,易脱落,豆荚发育不良,弯曲,不饱满。出现缺氮状时,及时施用氮肥,每667平方米追施尿素15千克,或硫酸铵30千克,以穴施或撒施为主,并辅以0.3%的尿素水溶液叶面喷施。2、磷素缺乏症菜豆缺磷时,植株生长缓慢,其他症状不明显,叶片仍为绿色。磷肥的施 1, Nitrogen deficiency Nitrogen deficiency of the bean showed weak growth, thin and thin leaves, light green leaf color, old leaves yellow, easy to fall, pod dysplasia, bending, not full. Nitrogen deficiency, the timely application of nitrogen fertilizer, topdressing every 667 square meters of 15 kg of urea, or ammonium sulfate 30 kg to the main application or spreading, and supplemented with 0.3% aqueous urea solution foliar spray. 2, phosphorus deficiency When beans lack phosphorus, plants grow slowly, other symptoms are not obvious, the leaves are still green. Phosphate fertilizer application