Assertion (A): Macronutrients are generally present in plant tissues in large amounts, in excess of 10 m mole kg−1 of dry matter.
Reason (R): Micronutrients are needed in very small amounts, less than 10 m mole kg−1 of dry matter.
Both A & R true and R does not explain A
Essential elements which are required in large quantities by the plants are called macronutrients and which are required in small quantities are called micronutrients they are differentiated based on their concentration of requirement and individually depend on their specific role in plants .