作物必需营养元素的概念作物生长需要多种元素，通过分析发现有７０多种元素存在于植物体内。但是，这些元素并不一定是作物所必需，正如美国植物生理学家阿诺所说：“必需元素一定存在于植物体内。但是植物体内的元素并非都是植物所必需。那么作物正常生长究竞需要哪些元... The Concept of Essential Nutrient Elements in Crops The growth of crops requires a variety of elements. According to the analysis, more than 70 elements are found in plants. However, these elements are not necessarily essential to crops, as Arnold, a US plant physiologist, put it: "Essential elements must exist in the plant, but not all of the elements in the plant are essential to the plant. What elements ...