Earthworms Thrive in Simulated Martian Soil, Could Make Space Farms a Reality
A group of researchers from Wageningen University & Research has found that earthworms can thrive and reproduce in simulated Martian soil. Given that the creatures are a crucial factor in making soil fertile, that means the first colonizers of Mars might be able to grow food on the Red Planet.
What we call Martian “soil” is in fact barren dust and rock that would require a serious boost if humans genuinely plan to establish farms on Mars and grow potatoes there like Matt Damon did in “The Martian.” In science terms, “soil” has to contain elements of organic matter from plants and animals.
After NASA’s Curiosity Mars rover completed its first soil analysis of the Red Planet back in 2012, scientists found that the planet’s regolith is a weathered volcanic type very similar to Earthly soils found in the Hawaiian Islands. Researchers conducted numerous tests trying to grow food plants using that simulant; first attempts proved unsuccessful but later they managed to achieve better results with the help of freshly-cut grass added to the growing medium.
Last year, a research group from Wageningen University in the Netherlands successfully grew 10 crop species, including tomatoes, rye and radishes, using a Martian soil simulant pumped up with fertilizers such as pig slurry. The researchers then added the manure to samples of the Mars simulant and to samples of “silver sand” where they were growing arugula lettuce and analyzed the outcome.
“The positive effect of adding manure was not unexpected, but we were surprised that it makes Mars soil simulant outperform Earth silver sand,” said Wieger Wamelink, lead researcher on the project, as cited by New Atlas.
After the arugula had germinated, the team added worms to some of the pots. Worms are also a key contributor to soil fertility because they digest dead organic matter and excrete a potent fertilizer that helps release nutrients like nitrogen and phosphorus. Their incessant burrowing also helps lighten up the soil, allowing air and water to seep through better.
“Clearly the manure stimulated growth, especially in the Mars soil simulant, and we saw that the worms were active,” Wamelink said, adding that the worms not only thrived but reproduced.
“However, the best surprise came at the end of the experiment when we found two young worms in the Mars soil simulant,” he said.
Altogether, the tests showed that the combination of worms and pig slurry helped the plants grow in Martian soil, which raises hopes for our ability to grow greens on the Red Planet sometime in the future.