"The total above-ground biomass produced on the Mars soil simulant was not significantly different from the potting compost we used as a control", Dr Wieger Wamelink said in a statement. Though their results have yet to be peer reviewed, the team reportedly managed its success by making the "alien" soil a bit more Earthlike. Lunar soil, for example, is extremely hydrophobic and Martian soil -- based on what we know from satellite analysis, at least -- isn't much better. However, by adding stuff like freshly cut grass and manure to the simulated soils, the researchers managed to significantly increase yields.
"That was a real surprise to us," Wamelink continued. "It shows that the Mars soil simulant has great potential when properly prepared and watered. The biomass growth on the moon soil simulant was less than on both other soils, about half of the biomass. Only the spinach showed poor biomass production."
While this is an exciting development in exoplanetary colonization, it's not like we can just shoot some seeds and Miracle-Gro at the red planet ahead of a manned mission and hope for the best. Martian soil is rich in heavy metals. There are plenty of plants that can grow in such soil without ill effect, but they tend to concentrate these toxins, making them inedible to humans. To that end, the research team is launching a crowdfunding campaign to finance its third round of experiments, which will focus on ensuring that the food grown on Mars won't poison the astronauts that eat it.