Agriculture on Mars has always faced the same obstacle. The soil of the red planet is barren. It contains minerals, but none of the organic nutrients that plants need to grow. Researchers from the University of Bremen in Germany have overcome this problem by relying on microbes capable of transforming Martian dust into usable fertilizer. Their results offer a concrete prospect of feeding future astronauts on site.
Agriculture on Mars relies on bacteria that make fertilizer from dust
Agriculture on Mars begins, in this study, with cyanobacteria, also known as blue-green algae. These resilient microorganisms feed on carbon dioxide, abundant in the Martian atmosphere, to produce biomass. The researchers cultivated them on a simulated Martian regolith, an artificial dust reproducing the composition of Mars’ soil. According to an article published by Interesting Engineering, this process requires no resources imported from Earth.
Once the cyanobacteria were cultivated in sufficient quantities, they were subjected to anaerobic fermentation, a process in which microorganisms degrade organic matter without oxygen to release nutrients. By preheating the biomass and maintaining the system at 35 degrees, researchers obtained a digestate, a nutrient-rich liquid directly usable as fertilizer.
A gram of microbes transforms Mars dust into 27 grams of edible plants and fuel
The produced fertilizer was then used to cultivate duckweed, known scientifically as Lemna sp., a fast-growing aquatic plant rich in proteins and commonly consumed in some regions of the world. According to a study published in the Chemical Engineering Journal, a single gram of dried cyanobacteria was enough to produce 27 grams of edible fresh vegetable mass.
In parallel, the fermentation produced methane, an energy-rich gas that could serve as fuel in a Martian base. Thus, the same process produces both food and energy, two critical resources for any long-duration mission. Tiago Ramalho, a doctoral student and lead researcher of the study, envisions a vegetable garden on Mars, solely fueled by local resources, without soil, fertilizer, or imported water.
Laboratory agriculture on Mars paves the way for autonomous space missions
These results were obtained in a laboratory, under controlled Earth conditions. However, Mars poses much more severe constraints, including intense radiation, reduced gravity, and extreme temperatures. The team plans to integrate this system with other survival technologies to test its robustness in conditions closer to Martian reality. Furthermore, the yield obtained remains about twice as low as that of a standard culture medium on Earth.
Nevertheless, this advancement fundamentally changes the perspective of manned missions to Mars. It demonstrates that an autonomous cycle, starting from local dust to resulting in food and energy, is scientifically feasible. Consequently, the researchers emphasize that this approach could also have applications on Earth, especially in regions where the quality of agricultural soils is rapidly deteriorating.
