The Martian
what does that "fertilizer" have in it that will allow the potato plants to absorb nitrogen?
We know that he fertilizes the plants with feces but what does it have in it?
We know that he fertilizes the plants with feces but what does it have in it?
I believe the answer is feces contains bacteria. When Whatney added the fertilizer (feces) to the soil from earth, he produced a mixture that would enable him to plant and grow potatoes.
The Martian