If nearly 79% of the atmosphere is made of nitrogen, how could there be a shortage of nitrogen in the soil?

Question

I know this is something do do with Nitrogen fixing bacteria but I don't understand...

Aubrey Arnold · Accepted Answer

Because dinitrogen is EXCEPTIONALLY inert....

We represent the dinitrogen molecule as #N-=N#...because (i) the filled bonding orbitals are so stable it is difficult to oxidize, and since the unoccupied molecular orbitals are high in energy, is (ii) difficult to reduce. A few microorganisms, such as bacteria found in the roots of legumes like peas and beans, have the ability to fix atmospheric nitrogen. However, convincing model systems that simulate nitrogen fixation and reduction have only recently been developed. In any case, the overall effect of all this is that we typically apply nitrogenous fertilizer—that is, nitrates and ammonium salts—when we grow plants and vegetables because they contain nitrogen in a soluble and useable form.

Andrew Armstrong · Answer

undefined The nitrogen in the atmosphere is not readily available for plants to use. It needs to be converted into forms such as ammonia or nitrates through processes like nitrogen fixation before plants can absorb it from the soil. Factors like inefficient nitrogen fixation, leaching, denitrification, and plant uptake can contribute to nitrogen depletion in soil despite its abundance in the atmosphere.