Which nutrient is NOT classified as a macronutrient?

The correct classification of nutrients distinguishes between macronutrients and micronutrients based on the quantities required by plants. Macronutrients are essential elements that plants need in larger amounts to support their growth and development. These include elements such as nitrogen, potassium, and calcium, which play crucial roles in various physiological processes.

In contrast, iron is categorized as a micronutrient. While it is vital for plant health, particularly in processes like chlorophyll synthesis and enzyme function, it is required in much smaller quantities compared to macronutrients. Understanding this classification is essential for effective nutrient management and ensuring that plants receive the appropriate amounts of each nutrient for optimal growth.