Which form of nitrogen is absorbed by paddy under waterlogged conditions?

✅Explanation:
-Under waterlogged conditions, the predominant form of nitrogen available for uptake by paddy (rice) is ammonium (NH₄⁺).
-Waterlogging creates anaerobic conditions, favoring the conversion of other nitrogen forms (like nitrate) into ammonium by certain bacteria.
-Paddy plants have adapted to efficiently absorb ammonium under these conditions.

📌 Other Options Explanations:
-Option A: N₂ (Nitrogen gas): While abundant in the atmosphere, N₂ is inert and cannot be directly absorbed by most plants. It needs to be converted into other forms like ammonium or nitrate through biological or industrial processes (nitrogen fixation).
-Option C: NO₂⁻ ion (Nitrite ion): Nitrite is an intermediate product in the nitrogen cycle and is usually present in low concentrations in the soil.
-Option D: Nitrate ion (NO₃⁻): Although nitrate is a common form of nitrogen absorbed by plants, under waterlogged conditions, it is readily converted to ammonium, making it less available for direct uptake by paddy.