Question

Which of the following is a primary nutrient?
A. Boron
B. Calcium
C. Sulphur
D. Nitrogen

Answer 1

Primary nutrients are also called macronutrients. ‘Macro’ means large, so macronutrients are those essential nutrients that are required in large quantities. Examples include carbon, hydrogen, oxygen etc.

Complete answer: Plants require nutrition in the form of nutrients for proper growth and development. In the absence of any of the essential nutrients, the normal life cycle of the plant will not complete. There are 17 essential plant nutrients which are directly absorbed from the air. While nitrogen is first fixed in the soil through nitrogen-fixing bacteria, which are absorbed by the plant. It is regarded as the primary nutrient. On the basis of requirement, plants nutrition is divided into two categories:

1. Macronutrients: They are those nutrients that are required in large quantities. It includes N, P, K, Ca, S, Mg, C, O, H.
2. Micronutrients: They are those nutrients that are required in low quantities. It includes Fe, B, Cl, Mn, Zn, Cu, Mo, Ni.
   The nutrient deficiency in plants may lead to certain diseases like tomatoes rotting, the brown heart of celery and tip burn of cabbage. The nutrient-deficient plants become more prone to pathogens. It can be understood that immunity of plants gets weakened if a nutrient deficiency occurs.
   Hence, the correct answer is option D.

Note: Nutrients that are present in the soil in the form of salts, plants take up or consume these elements in the form of ions. Nutrient deficiency can limit the yield of the crop. Therefore, certain fertilizers such as NPK are used in the field to supply nutrients to plants that are nutrient-deficient.