Which nutrient is classified as a macronutrient?

Calcium is classified as a macronutrient because it is required in relatively large quantities for plant growth and development. Macronutrients, which include elements like nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur, are essential for the overall health and functioning of plants. They play critical roles in various physiological processes, including cell wall structure, enzyme activity, and photosynthesis.

Calcium specifically contributes to the structural integrity of cell walls and is vital for controlling various plant physiological processes, such as nutrient uptake and signaling. The high demand for calcium in plant tissues, particularly in developing shoots and roots, highlights its importance as a macronutrient compared to micronutrients, which are needed in much smaller amounts.