Question

Why the plants cannot absorb nitrogen directly?

Answer 1

Answer:

plants do not use nitrogen directly from the air. This is because nitrogen itself is unreactive, and cannot be used by green plants to make protein. Nitrogen gas therefore, needs to be converted into nitrate compound in the soil by nitrogen-fixing bacteria in soil, root nodules or lightning.

Answer 2

This is because nitrogen is itself unreactive and cannot be used by green plants to make protein