Mars knew: Bacteria make Martian soil more fertile

It’s alfalfa that has shown an American research team that adding bacteria makes Martian soil more fertile. Plants grow better. Hollywood knew this before.

At the latest when Mars is colonized, most of the food should also be produced there. This is why scientists have been searching for astrological cultivation for years. This is a challenging area of ​​research because not all parameters of plant growth on Earth can be simulated.

But one thing is clear: It doesn’t work as easily as it did in the Hollywood movie “The Martian” with Matt Damon – but it’s similar from a distance. In the movie, astronaut Mark Watney (Damon) planted potatoes in Martian soil, added bacteria from a terrestrial soil sample and fertilized the plants with his droppings. can live on it.

Experiments recently conducted at Wageningen University in the Netherlands showed that farming on Mars with simple greenhouses would not work. The researchers had grown plants in an analog Martian soil produced by NASA based on volcanic sand from Hawaii and initially achieved good harvest results. But then they exposed the plants to radioactive radiation like that found on Mars. This reduced biomass growth by almost half. Research is now underway at underground farming sites.

A team of scientists from Colorado State University in Fort Collins, Colorado, USA, has been conducting research on astrological cultures for several years. Their most recent work was about showing how a potential crop could be improved. In doing so, it ignores problems such as radiation exposure, etc. and focuses only on the soil and its nutrient content as influencing factors.

After previous studies, including experts from Wageningen, it was already clear that plants can in principle thrive in the Martian regolith, that is, the soil there, American researchers looked for a way to provide them with vital nitrogen. They found it in nitrogen-fixing nodule bacteria of the genus Sinorhizobium meliloti.

These bacteria colonize the roots of many plant species on Earth. It was first discovered on alfalfa, but it can also be found in the roots of peas and beans. Bacteria bind nitrogen from the atmosphere and then make it available to plants in a soluble form. The plant, in turn, reacts to the return of substances that the bacteria need to survive.

In fact, the Colorado team noticed an improvement in plant growth in the regolith. The shoots of plants with root bacteria were 2.5 times longer than those without bacteria. The biomass of shoots and roots is doubled.

It turns out that bacteria also enter into a symbiosis with plants in the soil of Mars. However, other limitations on Martian soils meant that the number of root nodules formed was barely a quarter of the usual amount in soil.

Accordingly, it was not possible to enrich the regolith with nitrogen outside of individual plants. However, this must also have something to do with the low nitrogen enrichment in the Martian atmosphere. While Earth’s atmosphere contains 78 percent nitrogen, this value is as thin as 1.2 percent on Mars.

The research team published the results of their work in the journal Science PLUS ONE Posted, still satisfied. The evidence alone that microbes can also form symbiotic bonds in the regolith is promising. Now more studies must be done. After all, we know from studies on Mars compounds that the regolith lacks a large number of other micronutrients, such as copper, boron or molybdenum.

The researchers see no alternative to their work. Due to the steadily increasing environmental problems on our home planet, humanity must prepare for its inability to survive longer as a “one planet species”. So there is no way to get around a long-term working exotic cultivation.