Question

Plants cannot use nitrogen
in the soil directly .Why?​

Answer 1

Answer:

Plants do not use nitrogen directly from the air because nitrogen is noble gas and 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 so that plants can use it.

Explanation:

Answer 2

$\sf \huge \underline{answer} \implies$

But 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.