If we are going to establish permanent bases on the Moon or Mars we need to know that they can be self-sufficient. There are questions about the production of water and the potential dangers of cosmic rays, and we also need to consider food. Dutch researchers set about addressing the latter, and obtained some interesting results.
As reported in the journal Open Agriculture, researchers led by Wieger Wamelink at Wageningen University & Research in the Netherlands managed to produce crops in Martian and lunar mock soils developed by NASA. They found that it is possible to grow food for future astronauts directly in the soil of another world and that the crops grown can produce viable seeds that can then be replanted.
The simulated soils were mixed with organic matter to provide nutrients for the crops and standard Earth soil was used as a control sample. The team attempted to cultivate 10 different crops: garden cress, rocket, tomato, radish, rye, quinoa, spinach, chives, peas, and leek. The results show that it’s only bad news for the Popeyes among the astronauts because spinach was the only crop that didn’t reach a point where the scientists could harvest edible parts.
“In this limited preliminary experiment, we show that crop growth on Mars and moon soil simulants is possible," the authors write in the paper. "The addition of organic matter to both the Mars and moon regolith simulants resulted in the germination and growth of all ten crop species. Several crops produced fruits and seeds on both Mars and Moon simulants.”
The Earth soil produced the most plant biomass but the data suggest that the mock Martian soil has a similar productivity to the soil we have on Earth. The soil from the Moon was less productive. Flowering plants had previously been tested in extraterrestrial soil simulants, but the researchers believe this is the first time that fruits have been harvested from such experiments.
"We were thrilled when we saw the first tomatoes ever grown on Mars soil simulant turning red. It meant that the next step towards a sustainable closed agricultural ecosystem had been taken," said Wamelink in a statement.
For three out of the 10 species planted (radish, cress, and rye), it was possible to harvest enough seeds for a germination experiment, and no germinating plants died during the 20 days of the experiment. The radish germinated better in the Martian and Earth soil than the Moon soil.
This experiment is an early look at what we might need in the future, but if space agencies are serious about settlements, we need to know what can be grown beyond Earth.