Coming soon: a market garden on Mars

Experiments using simulated Martian soil produce surprisingly good results.

The idea of permanent human settlement on Mars might have shifted from the fanciful to the possible, but to become probable we need to work on the issue of food sustainability.

One of the big questions is how well, if at all, plants will take root and produce fruit in the iron-rich dirt on the Red Planet.

In an effort to answer that question, researchers led by Wieger Wamelink of Wageningen University, Netherlands, used their best geochemical data to produce a simulant of Martian soil – and one of the Moon’s, as well.

Into these artificial soils (known as regoliths in the jargon) they planted 10 popular food species: garden cress, rocket, tomato, radish, rye, quinoa, spinach, chives, pea and leek.

The soils were augmented with organic matter in the form of chopped up pieces of the same plant varieties, working on the not unreasonable assumption that pioneering Martian or lunar market gardeners would be smart enough to dig the unused parts of past crops back into the soil to fertilise the next. Surprisingly, the results were good. Most of the Moon-soil plants grew quite weakly, but the Martian ones shot up with only slightly less vigour than the Earth controls.

The exception was spinach, which, Wamelink and colleagues report in the journal Open Agriculture, “started to flower after only a few small leaves were formed” and thus produced nothing of substance. Good or bad news, depending on your tastes.