Macronutrients - Those nutrients that are needed by the plants in large quantities are known as macronutrients. They are generally present in the plant tissues in large amounts i.e. in excess of 10 mmole Kg^-1  of dry matter. For e.g - carbon, hydrogen etc. 

Micronutrients - Are the elements which are needed by the plants in very small quantities i.e less than 10 Kg^-1  of dry matter. For e.g. zinc, boron etc. 

Beneficial elements - The elements are plant nutrients that may not be essential, but are beneficial to plants. For e.g/ - Selenium is  beneficial to higher plants.

Toxic elements: Micronutrients are required by plants in small quantities. An excess of these nutrients may induce toxicity in plants. For example, when manganese is present in large amounts, it induces deficiencies of iron, magnesium, and calcium by interfering with their metabolism.

Essential element - The elements that are absolutely necessary for plant growth and reproduction. The requirement of these elements is specific and non-replaceable. For example carbon, magnesium , phosphorous , zinc etc.