Answer: larger.
- A larger
- B smaller
- C equal
- D only trace
Correct answer: A. larger
Explanation: Macronutrients (e.g. N, P, K) are required in relatively large amounts.
Atmospheric N₂ is fixed into ammonia by nitrogen-fixing bacteria (protected from oxygen by leghaemoglobin in root nodules), converted to nitrate via nitrification for plant uptake, and eventually returned to the atmosphere as N₂ via denitrification, completing the cycle.
Concept context
Essential mineral elements, their roles and deficiency symptoms. Nitrogen fixation and soil nutrition.