Explanation:
So plants need nitrogen to make their proteins (proteins are made of carbon, hydrogen, oxygen, nitrogen and small amounts of sulfer).
Unfortunately, the nitrogen in the atmosphere is inert (unreactive).
But there are still other ways to get nitrogen:
1. Lightning. It causes some of the nitrogen to combine with oxygen, forming nitrogen oxides. These dissolve in rain and are washed into the soil where they form nitrates.
2. Artificial fertilizers. There are literally ammonium compounds and nitrates in those bags that people sell.
3. Nitrogen-fixing bacteria. So there is bacteria in the soil that live in root nodules on plants.
What do they do?? They use nitrogen from air spaces in the soil and combine it with other subsrances to make ammonium ions and other compounds.
4. Nitrifying bacteria. They turn ammonium ions into nitrates, which plants can use again. (so basically they serve nitrogen dish to the plant)
They convert the nitrogen containing substances into BETTER nitrogen containing substances for the plant
5. Denitrifying bacteria. FINALLY these bacteria turn nitrates and ammonia in the soil into nitrogen gas, which goes back to the atmosphere.
And the cycle goes on from the start...
Note that 1-3 are just ways in which nitrogen can be converted into a more reactive form.
I Hope this helps
