The ancient Mayans could have the answer to help us farm on Mars

A new study published in the science journal PLoS ONE suggests that the ancient farming technique of intercropping could help more crops grow on Mars.

In the study, researchers used plants that are known to grow in Martian soil, specifically peas, carrots and tomatoes, according to Smithsonian Magazine. The researchers found that the tomato plants thrived more in an intercropping environment than its fellow carrots or tomatoes.

What is intercropping? What does it have to do with the Mayans?

Intercropping is described by the study as “an ancient technique used on Earth that involves growing two or more crop species simultaneously in the same field.”

Using intercropping techniques has been proven to have benefits when compared to planting a single crop (known as monocropping), such as the plant having more nutritional value.

The U.S. Department of Agriculture shares that intercropping can look like multiple crops that share the same row or beds. The plants have to be close enough to have biological interactions. In North American indigenous tribes, a specific form of intercropping existed for hundreds of years known as “The Three Sisters.”

The Three Sisters was a name for multiple native crops that often grew together, with the USDA explaining that “The Iroquois and the Cherokee called corn, bean, and squash the three sisters’ because they nurture each other like family when planted together. … These three plants thrive together better than when they are planted alone.”

In Central America, a similar process to the Three Sisters intercropping method was known as “milpa,” where instead of corn, bean and squash being planted together, it was actually maize and soybeans, per USDA.

The Meso American Research Center from the University of California, Santa Barbara, reports that modern Mayan farmers continue use the milpa method to grow chiles, corn, beans and squash.

The intercropping tests

Smithsonian Magazine explains that the research team conducting the study recreated Mars-like conditions in a greenhouse, using rocks, dust and special sand called regolith in pots. This replicates the soil found on Mars.

To compare, they also had other pots full of normal potting soil and river sand.

The results were somewhat promising. In the simulated Mars soil, tomatoes grew the best when near peas and carrots, except the peas and carrots had less success growing with the tomatoes.

Lead author of the study, Rebeca Gonçalves, told Reuters, “Since this is pioneering research, where it’s the first time that this intercropping technique is applied to space agriculture, we really didn’t know what to expect. And 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. 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.”

Gonçalves also told Popular Science that tomatoes, carrots and peas were chosen for this study because they were high in antioxidants, vitamin C and beta carotene, all nutrients that are normally lost in dehydrated space food.