目前已发现植物体内含有七十多种元素.其中碳、氢、氧、氮、磷、钾、钙、镁和硫九种元素,占植物体全部重量的大部分,通称为大量营养元素.钼、硼、锰、铜、锌、钴、氯等,在植物体内含量很少,仅占十万分之几,甚至百万分之几,所以称为微量元素.铁在植物体内含量也很低,也常列入微量元素中.这些元素生理作用有很强的专一性,多数是酶或辅酶的组成 It has been found that plants contain more than seventy kinds of elements, of which carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium and sulfur nine kinds of elements, accounting for most of the total plant weight, commonly known as a large number of nutrients. , Boron, manganese, copper, zinc, cobalt, chlorine, etc., are very little in plants, only a few hundredths of a few, or even a few millionths, so called trace elements. Iron is also very low in plants , Often included in trace elements in the physiological role of these elements have a strong specificity, most of the enzyme or coenzyme composition