Mayan Intercropping Could Be Key to Food on Mars

The international space community has its sights set on humans landing on Mars by the mid-2030s, but a big question remains once astronauts get there: what will they eat? Researchers in the Netherlands at Wageningen University & Research are working to solve that particular problem in the long-term, when humans theoretically colonize the planet and won't exactly be able to rely on Uber Eats. In a new study that mimicked Martian conditions in a controlled greenhouse, attempts to grow food were boosted by using a technique pioneered by Mayans called intercropping. Per Reuters, this agricultural method involves growing a combination of mutually beneficial crops together.

When the researchers tested intercropping different groups of tomatoes, peas, and carrots—grown in the same pots or alone—with soil that chemically and physically matched what's found on Mars, tomato yields were boosted when grouped with peas. The peas and carrots preferred to grow alone, but seeing tomatoes thrive with thicker stems, more and bigger fruit per plant, and faster maturation was an exciting find. "The fact that it worked really well for one out of the three species was a big find, one that we can now build further research on," astrobiologist and lead author Rebeca Gonçalves told Reuters. "Now it's just a matter of adjusting the experimental conditions until we find the most optimal system. It can be different species, more species, different ratio of species."

Per Phys.org, planting peas close to tomato plants has been known to benefit tomatoes because of the way green peas influence the soil—nitrogen pulled in from the air by pea plants turns into ammonia, which is released into the dirt, fertilizing it in a way tomato plants like. To create a Mars-like atmosphere, the researchers not only replicated soil conditions, but controlled the greenhouse to replicate what one might look like 140 million miles away, including the gases, temperature, and humidity it would have. While they couldn't taste their crops until they underwent testing, they have tried out past samples. "I thought the Martian ones were sweeter than the Earth ones," says coauthor Wieger Wamelink. (Ideas for getting Martian rocks back to Earth on the cheap? NASA is all ears.)