How will future inhabitants on Mars and the Moon get their veggies? Northern Arizona University doctoral candidate Laura Lee has been seeking the answer to that question. And it turns out that northern Arizona might hold some specific answers.
Plants need soil to grow, but launching bags of soil into orbit is expensive. The Moon and Mars lack living soil, but have surfaces made up of regolith—a sterile, pulverized rock that contains phosphorus but no nitrogen. Both of these chemicals are vital to plant growth.
So Lee decided to investigate if the traditional “Three Sisters” of Indigenous American agriculture—corn, squash, and beans—could grow in material resembling the Moon’s and Mars’ regolith. Her simulated regolith was harvested as volcanic debris from Merriam Crater, just east of Flagstaff. Lee tried two different additives: a nitrogen-rich fertilizer, and a fertilizer made of processed human waste. She also added a microscopic root fungus to each regolith-fertilizer mix.
Corn grown in Martian regolith simulant and fungus had the highest leaf chlorophyll, a major indicator of plant health, but corn grown in Lunar regolith simulant with fungus and human waste was larger, lived the longest, and produced visible ears.
Lee is interested in next growing the Three Sisters together in a single regolith plot. She’s curious to see if the Three Sisters symbiosis, known for millennia to Indigenous farmers on Earth, could persist on the Moon or Mars. Northern Arizona’s volcanic geology, and the region’s long-time Indigenous farming practices, might just help shape humanity’s spacefaring future.
This episode of Earth Notes was written by Justin Creiver, and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.
