Question

In which form is nitrogen procured by the plants?

Answer 1

i think so in the forms of nitrates

Answer 2

Vestigial Nitrogen gas in the atmosphere is in unusable form. So by some bacteria like Rhizobium and some other, it is converted into $HNO_3$ i.e Nitric Acid(also called Hydrogen Nitrate. It can be also fixed by lightning) which is the form usable by plants