Humans will one day set foot on Mars, and we can’t bring all our food with us. Most if not all of it will have to be grown on the surface of the currently inhospitable planet. Before we convert the atmosphere into a breathable one and completely alter the climate, though, we need to know if the soil itself is fertile.
Fortunately, NASA is working on this problem using simulated “Martian gardens” found at both the Kennedy Space Center and the Florida Tech Buzz Aldrin Space Institute.
On Earth, we almost always require soil to grow our food – a soft, wet, finely-ground coagulation of matter. “Soil, by definition, contains organics; it has held plant life, insects, worms,” Ralph Fritsche, project manager for food production at Kennedy Space Center, said in a statement. “Mars doesn’t really have soil.”
Instead, it has volcanic debris which, although potentially fertile, also contains a bunch of harmful metals and substances that could poison any hungry future colonists.
Collecting the closest to Martian-like soil on Earth – volcanic soil from Hawaii – various quantities of crumbled rock, water, and nutrients were mixed with the seeds of various crops in order to see which conditions are best for starting some off-world agriculture. The project is currently in its early stages, but so far, lettuce has been successfully grown.
Over a 3.5-week-long pilot study, biochemists and ecologists attempted to grow lettuce in three different environments – one with a biochemical growth stimulant and nutrients, one with just nutrients, and one in terrestrial potting soil.
As many as 15 of the 30 seeds in the stimulant-laced environments died before the trial ended, mainly due to their roots not becoming strong enough. However, those that survived did flourish into edible lettuce crops.
Within the stimulated soils, though, the germination rate was up to three days slower than in the terrestrial soil groups, meaning that farming on Mars will take a bit longer than it does on Earth.
A nine-month-long test is due next, which will not just test out lettuce, but radishes, Swiss chard, kale, Chinese cabbage, snow peas, dwarf peppers and tomatoes. If successful, expect the first members of a Martian settlement to be huge fans of garden salads.
This hasn’t been the only attempt to grow crops in simulated Martian soil. Back in June, a team of Dutch scientists demonstrated that radishes, peas, rye, and tomatoes could indeed be cultivated, all of which contain no dangerous levels of health-harming heavy metals like lead, copper, or cadmium. They also grew potatoes, garden rocket, and watercress, but further testing is required to see if these are safe to eat too.