<span>Nitrogen fixation
This process creates organic compounds, including ammonium, that contribute to the growth of a plant in much the way fertilizer does. Many plants have evolved to facilitate nitrogen fixing bacteria in their roots as to promote production of these organic compounds when the soil quality is poor or lacking in these bacteria.</span>
Plants absorb me from the soil through assimilation, I am eaten by animals the animals and plants die and decompose where I am released back into the soil, weathering and erosion cause me to release out of rocks, I then find my way into the ocean being carried by water, I then return to the soil through the water.
I believe it is a 2:1 ratio of hydrogen to oxygen, because the way i learned was that carbon hydrogen and oxygen have a ratio of 1:2:1, respectively.