As fiction goes, it’s relatively plausible - Watney’s a good enough botanist to be selected for the space program, and in the bit of the novel/film he’s working on potatoes, he’s not doing much else, so can dedicate as much time as is necessary to get what he needs. For plot-convenience reasons, he’s in a situation where he’s got enough space, starter potatoes and existing food to make it all work, too. Andy Weir got those quantities by consulting experts rather than guessing, so they should be realistic.
As fiction goes, it’s relatively plausible - Watney’s a good enough botanist to be selected for the space program, and in the bit of the novel/film he’s working on potatoes, he’s not doing much else, so can dedicate as much time as is necessary to get what he needs. For plot-convenience reasons, he’s in a situation where he’s got enough space, starter potatoes and existing food to make it all work, too. Andy Weir got those quantities by consulting experts rather than guessing, so they should be realistic.
Botany was just his scientific pursuit, he was the ship’s mechanic and flight engineer.
I hate that they just didn’t even mention that in the movie, made him being so creative with tools and fixing things seem strange.