花木在生长发育过程中需要大量的氮、磷、钾、钙、镁等元素,同时还需要很少的铁、锰、锌、铜等微量元素。花卉缺少某种元素时,就会表现出相应的缺素症状,如缺氮症状为生长势弱,叶色浅绿,基部叶片发黄或呈现浅褐色;缺磷时叶片蓝绿且略带紫色;缺钾表现为老叶片黄化,尤以新叶表现严重。但是,由于花木对缺少同一种元素的敏感程度不同,加之各种缺素症状又常常表现有相似之处,故形态上的症状只能 Flowers and trees in the process of growth and development need a lot of nitrogen, phosphorus, potassium, calcium, magnesium and other elements, but also requires little iron, manganese, zinc, copper and other trace elements. Flowers lack of an element, it will show the corresponding lack of symptoms, such as nitrogen deficiency symptoms of weak growth, light green leaves, the base leaves yellow or pale brown; lack of phosphorus when the leaves are blue-green and purplish ; Potassium deficiency showed yellowing of old leaves, especially in the performance of new leaves. However, due to the different sensitivity of flowers and plants to the lack of the same element, coupled with various deficiencies and symptoms often show similarities, so the morphological symptoms can only