Alfalfa may be the first crop to grow on Mars

Header image: An artist concept depicts a greenhouse on the surface of Mars. Plants are growing with the help of red, blue and green LED light bars and a hydroponic cultivation approach. Image credit: SAIC

Growing plants on Mars will look considerably different to gardening here on Earth. For starters, the lack of an atmosphere and constant radiation will mean they’ll have to be grown indoors in a protected environment. We’ll probably need to use artificial lighting, but could Mars provide soil and water? Researchers at Iowa State University have been investigating and have found that we may be able to grow alfalfa on Mars. 

Strictly speaking, Mars does not have soil. Soil is a living ecosystem, teeming with life. What Mars has is rock, mostly volcanic basalt. Basalt doesn’t contain much in the way of plant food. If we want to grow plants in basalt, then we need to (a) make the basalt more fertile and (b) choose plants that can grow in less-than-ideal conditions.

For this research, the scientists tried growing several different crops in finely ground basalt (standing in for Martian regolith). They found that while turnips, lettuce and radishes did not grow well, alfalfa was able to thrive.

What’s more, they found that alfalfa improved the basalt soil. As a result, crops grown in basalt previously used to grow alfalfa grew much better. (Turnip yields increased by 311%.)

We live on a wet planet. Water covers about 70% of Earth’s surface. Only 3% of that is freshwater, and much of it is unavailable – locked up in glaciers and ice caps or buried too deep for us to get at it. Still, plenty of places on Earth have enough freshwater to grow plants. However, the same is not true on Mars.

We think that the water on Mars is too salty to