Which element is not a plant macronutrient?

Which element is not a plant macronutrient?

• A. Magnesium
• B. Iron
• C. Calcium
• D. Sulfur

Answer: (B)

Plants need certain elements in different quantities. Macronutrients are the elements used in larger amounts to build tissues and support growth, while micronutrients are needed only in trace amounts for specific physiological processes. Among the options, calcium, magnesium, and sulfur are required in relatively large amounts and are classified as macronutrients (with calcium and magnesium often called secondary macronutrients). Iron, although essential, is needed only in very small amounts, so it is a micronutrient rather than a macronutrient. This is why iron is not a plant macronutrient.

Plants need certain elements in different quantities. Macronutrients are the elements used in larger amounts to build tissues and support growth, while micronutrients are needed only in trace amounts for specific physiological processes. Among the options, calcium, magnesium, and sulfur are required in relatively large amounts and are classified as macronutrients (with calcium and magnesium often called secondary macronutrients). Iron, although essential, is needed only in very small amounts, so it is a micronutrient rather than a macronutrient. This is why iron is not a plant macronutrient.