If we’re going to keep ourselves alive on Mars then we need to create a sustainable agricultural ecosystem, and the news that earthworms have managed to reproduce in a Mars soil simulant could be an important step towards that.
During the Food for Mars and Moon experiment at Wageningen University & Research, which was looking at how to stimulate growth in Mars-like soil, the biologists added adult worms and pig slurry (in place on human excrement) to a Mars soil simulant provided by NASA.
But, unexpectedly, as well as allowing the biologists to grow over a dozen crops, the experiment also produced two young worms.
“Clearly the manure stimulated growth, especially in the Mars soil simulant, and we saw that the worms were active. However, the best surprise came at the end of the experiment when we found two young worms in the Mars soil simulant,” said Wieger Wamelink of Wageningen University & Research.
Worms are very important for a healthy soil, not only on Earth but also in future indoor gardens on Mars or the moon.
They thrive on dead organic matter such as old plant remains, which they eat, chew and mix with soil before they excrete it. This poo still contains organic matter that is broken down further by bacteria, thus releasing nutrients such as nitrogen, phosphorous and potassium for use by the plants.
By digging burrows the worms also aerate and improve the structure of the soil, making watering the plants more effective. The latter proved to be very important in earlier experiments where water would not easily penetrate the soil. Wamelink confirmed that, “The application of worms will solve this problem.”
The soil stimulants, delivered by NASA, originate from a volcano in Hawaii, which simulates Mars, and a desert in Arizona, which simulates the Moon.
Since staring the experiments in 2013, the biologists has had success in growing crops such as green beans, peas, radish, tomato, potato, rucola, carrot and garden cress, which have all been tested to make sure they are safe for human consumption.
The biologists organised a dinner based on the harvested crops for the people that supported their research via a crowdfunding campaign.