Airlock Breach. When Airlock 1 breached, causing a gaping hole in The Hab, the potatoes were freeze dried and the bacteria in the soil assumed dead. Because of this Mark was unable to grow any more potatoes and could only eat the ones he still had with him.
In The Martian, potatoes are successfully harvested after 48 sols (a Martian solar day – 24 hours 39 minutes long), but the success of the venture does not last: Watney's potato-growing is put to an abrupt end as the front of his habitat blows off, exposing his entire crop to the Martian air.
However, they don't contain much protein, which could lead to muscle wastage over time – so like Mark Watney in The Martian, anyone trying to survive on just potatoes would need to supplement them with vitamin and mineral supplements.
The math works out for fertilizer, but did Watney grow enough potatoes? Watney estimates that he grew 2,000 potatoes and needed 1,100 calories per day (1,500 total, but he factored in his other rations).
But the scientists faced a steep challenge. Conditions on Mars are not hospitable to biological life. The planet's soils are salty, thin, and lacking in chemicals like nitrogen, which helps plants grow.
The Martian: I'm gonna dip this potato in some crushed Vicodin
Why couldn't Mark Watney grow potatoes again?
When Airlock 1 breached, causing a gaping hole in The Hab, the potatoes were freeze dried and the bacteria in the soil assumed dead. Because of this Mark was unable to grow any more potatoes and could only eat the ones he still had with him.
Could you grow potatoes on Mars like in The Martian?
In the story, astronaut Mark Watney (played by Matt Damon in the movie), survives being stranded on Mars by growing potatoes—using his own feces for fertilizer. Now, a new experiment here on Earth has shown potato plants can actually grow in "near-martian" conditions.
All the plants/potatoes were dead from lack of oxygen and sub freezing temperature. The bacteria in the poop soil as well. And his source of fuel that he could turn into water. So he had nothing to plant, in soil that was sterilized, with no water to sustain it.
With no means of farmable materials on Mars, Watney uses potatoes, brought for the crew's thanksgiving meal, to create a potato farm, which he fertilizes with human feces, prolonging his life long enough for the anticipated rendezvous with his crew.
Mark was consuming approximately 1500 calories a day. He says while doing the math for his potato farm: “For my height and weight, if I'm willing to starve a little, I'll need 1500 calories a day.”
On Mars, Watney did not have any man-made fertilizers available to him. He was not planning to stay there for a long time, let alone having to farm there, so his feces acted as organic waste that contained nutrients.
Mars is a planet with a very similar daily cycle to the Earth. Its sidereal day is 24 hours, 37 minutes and 22 seconds, and its solar day 24 hours, 39 minutes and 35 seconds. A Martian day (referred to as “sol”) is therefore approximately 40 minutes longer than a day on Earth.
The soil on Mars is not suitable for plant growth. Mars is a barren and inhospitable planet, and the soil on its surface is mostly composed of fine-grained, rocky particles that are low in organic matter and nutrients.
In the film, Damon's character, Mark Watney, who was an astro-botanist, ingeniously used faecal waste to fertilise his Martian garden. Billions and billions of bacteria call poop home-sweet-home. And that's exactly what Martian soil needs in order to sustain plant life—microbes.
The earliest archaeologically verified potato tuber remains were found at the coastal site of Ancón (central Peru), dating to 2500 BC. There is also recent evidence from stone tools of potatoes suggesting evidence of potatoes existing as far back as 3400 BC.
Combined with the fact that Watney was doing hard labor on only potatoes (which he was rationing), it would not be feasible to survive off of potatoes for such a long period of time. Ferriera, M. "6 Essential Nutrients: What They Are And Why You Need Them" Healthline.
Watney specifically mentions in the scene in the movie that he run out of ketchup seven days prior. He was probably using vicodin not for the taste, but for the side effects. The taste itself is just horrible -- I had a tooth extracted and I tried swallowing a pill without enough water and gagged.
How did Mark Watney in The Martian get so many potato plants out of fewer than 20 potatoes? It looks like he cut them in half to plant them, yet he somehow was able to plant 400 (according to Watney) potatoes.
In “The Martian,” Damon's character, astronaut Mark Watney, produces water by burning leftover rocket fuel and extracts the hydrogen from the resulting chemical reaction.
How does Mark save himself from an impaled satellite?
Ouch. In this instance being impaled saved his life by creating a seal where his suit breached. Watney is able to return to the habitat only to realize that he has been abandoned on mars and left for dead. Once he performs some rudimentary medical treatment, Watney pulls himself together and gets to work.
When it comes to botany, The Martian was impressively accurate. Experiments have shown that Martian soil would be capable of supporting crops, with human waste used as an organic fertiliser.
Watney uses ASCII language to communicate with NASA. They ask Watney how he survived. In reply, he writes on cards and holds them up to the Pathfinder camera.
With an atmosphere 100 times thinner than Earth's, only half the amount of sunlight, no known accessible fresh water, and average temperatures of -81 degrees Fahrenheit, Mars is the most challenging environment in which humans have ever planned to produce food.
