The experiment was meant to mimic the soil conditions on mars to test the viability of harvesting 10 crops including tomatoes, peas and rye.
The Mars-equivalent soil produced less crops than earth soil but not a massive difference. This suggests that with the right conditions, early Mars settlers could possibly sustainably feed themselves with grown crops.
“The production of biomass on the Mars soil simulant was lower than on Earth control, but it was a minor difference and caused by one of the trays that showed less growth,” said lead researcher Wieger Wamelink from Wageningen University & Research centre in the Netherlands. “That was a real surprise to us. It shows that the Mars soil simulant has great potential when properly prepared and watered.”
The researchers also tested the same crops in soil that is meant to mimic lunar soil. The crops were: tomato, rye, radish, pea, leek, spinach, garden rocket, cress, quinoa and chives. The Moon mimicking soil only produced about half as much the Mars crops. Spinach performed particularly terribly with the lunar soil.
To find soil that was chemically similar to that of Mars soil and Moon soil, the researchers had to go to some of the most extreme places on the earth. Mars soil came from a volcano on Hawaii and the Moon soil was gathered in a desert in Arizona. A control of regular potting compost was also used.
But there are some major things to take caution with this Mars soil experiment.
First, it has not been peer reviewed and we are taking the researchers at their word. To be fair these Wageningen University researchers have published previous papers on space crops.
Second, only the soil conditions were mimicked, not the entire atmosphere. They were not exposed to the harsh conditions that martian crops will be forced to cope with, like space radiation and huge swings in heat and cold.
The crops were grown in a glass house under Earth’s atmosphere, with stable humidity, light, and temperature – but Wamelik explains that this is because “we expect that first crop growth on Mars and Moon will take place in underground rooms to protect the plants from the hostile environment”. That’s fair enough, but we still can’t predict exactly how being on another planet will affect the process.
Third, and the most important point. We don’t know if these foods grown this way are even edible and nutritious.
“The soils contain heavy metals like lead, arsenic, and mercury and also a lot of iron,” said Wamelink. “If the components become available for the plants, they may be taken up and find their way into the fruits, making them poisonous.”
