Plants prefer to absorb nitrogen in what form

Hope this helps. Nitrogen assimilation in plants. Plants absorb nitrogen from the soil in theform of nitrate (NO3−) and ammonium (NH4+). In aerobic soils where nitrification can occur, nitrate is usually the predominant form of availablenitrogen that is absorbed. ... Ammonium ions are absorbed by theplant via ammonia transporters.

They prefer to absorb N (nitrogen) in gas from .And I wouldn’t say it is a preference but availability,the availability of nitrogen in the air is almost 80% and since plants already absorb other gases like CO2 (g) from the air they also in absorb N (nitrogen).