Choose the forms in which most plants absorb nitrogen:
I. Proteins
II. Nitrates and nitrites
III. Urea
IV. Atmospheric nitrogen
Choose the correct option.
Most plants absorb nitrogen in the form of nitrates, nitrites and urea. They cannot use up atmospheric nitrogen as it is un-reactive. This nitrogen needs to be converted into absorbable forms by certain nitrogen-fixing bacteria so that they can be taken up by plants.