Updated: Jan 30, 2021
We all remember the scene from the award-winning movie - ‘The Martian’, where Matt Damons’ character Mark Watney colonized Mars by planting potatoes in order to survive. However, is it actually possible to grow potatoes in Mars the exact same way that Mark Watney did in the movie? Since this is a broad topic to cover, hence I am segregating this into multiple smaller modules/blogs for investigation. This is the Martian Potatoes Series.
First, we would need to consider which aspects do we need to analyze: the potato life cycle; process of germination; the soil and atmospheric composition of earth compared to that of mars; fertilization; amount of water and sunlight need and also the process of precipitation shown in the movie possible. We will need to dissect every step of what Watney did in the movie. The movie was set in the year 2035. Though it seems that he used some very primitive techniques in the whole process, and even though it’s 15 years from now, the surface of mars would not change considerably.
Now we need to consider how to grow potatoes on earth:
· Place: Potatoes grow best in soil that is rich in organic matter and well-drained, they also require plenty of sun. They grow better in loose soil. However, they cannot grow well in extreme heat or dry soil. A soil temperature of around 40 Fahrenheit or 4.4 Celsius and the soil slightly acidic (a PH of 5 to 7 is ideal).
· Time: The best time to plant the potatoes would depend on the place where they are going to be planted. If it’s planted in a place with extreme heat such as India or California then the best time is before winter, if it’s somewhere temperate then late winter is ideal, since they can grow well during spring. If it’s being planted somewhere cold such as Sweden or Canada, then plant them before summer starts. The ideal temperature for growing potatoes is 60 to 75 Fahrenheit and anything above that is too warm.
· How to plant: You can either buy seeds or plant the potatoes when they have started to sprout; growing them from seed is quite difficult hence it is not usually advisable, but it’s easier to ensure that they are disease-free. They need to be planted in the soil in a trench form three inches deep and each potato needs to be about a foot apart. Then two or three weeks after planting, close the trench and push the loose dirt up so that most of the potato is submerged in the soil.
· Other care: Potatoes need 1-2 inches of water per week. Wait for about 1-2 weeks after planting to start watering. Also don’t water 2 weeks before harvest or when the vines start turning yellow. Potatoes will thrive when there is full sun and need about 8 hours of sunlight (Since there is no ‘sun’ present where Watney is growing the potatoes hence we would need to analyze whether the lights which were shown in the movie can be a substitute for the sunlight). However, the tubers of the potato need the protection from too much-prolonged exposure to light, especially artificial light as it causes the potatoes to produce ‘solanine’ and hence turn green which can be fatal to humans
· Harvesting: If all the conditions are ideal, and there are no problems which arise, one can expect to get 5 to 10 potatoes from each plant. They would be ready to harvest after typically 18 to 20 weeks or between 125 and 140 days after planting. They are ready when the plant starts turning yellow.
The question I had when I first watched the movie was - can we really grow a potato from a potato. As mentioned above, we can in fact grow potatoes from another potato, but it is better to grow them from potato seeds since it’s easier to ensure that they are disease-free. One needs to cut it side down with the eyes pointing up, similar to what Watney does in the movie.
However, they do need the ‘eye’ or spore in the potatoes in order to be planted, and that is not shown in the movie when he first planted the potatoes. The spore of the potatoes is the most important part when planting the potatoes- the spores have buds in them which will give rise to the roots; and that is how potatoes reproduce through vegetative propagation. Hence technically he cannot successfully grow potatoes without the spore or eye. But it is possible that the spores developed when we first catch a glimpse of the potato to the planting scene since it is quite hard to squint and see the potatoes.
There is a huge possibility however that because of the difference in eras and technology available – 15 years can make a huge difference - such errors in the movies can be overlooked at times. Nevertheless, there is still plenty left here to analyze and investigate. In the next post we will consider the difference in the soil and atmospheric composition of mars and earth (including difference in sunlight). This is just the beginning- the first post in the ‘Martian Potato Series’.