A combination of fungi and compost could make lunar regolith more fertile and one day help astronauts grow crops on the Moon, according to new research based on experiments on gram plants.
but future outposts moon There will be a need to be as self-reliant as possible to avoid the high cost of constantly having to switch off supplies Earth. If crops can be grown on the Moon, it will be an important step in this direction.
The problem is that the dirt on the Moon – what we call regolith – isn’t particularly good for growing plants.
Unlike soil on Earth, which is full of organic matter, regolith contains no microorganisms and no organic matter in general. And, while it contains some important nutrients, it is also full of toxic metals like aluminum, copper, and zinc. Additionally, it is not particularly permeable to water – which is a problem when you want to water your crops.
Therefore, scientists aim to treat lunar regolith to make it more suitable for growing plants. Many experiments have been done with this. Now, a team of scientists has discovered a new mixture that includes organic materials commonly used for soil regeneration on Earth that increases the fertility of regolith.
“The research is about understanding the feasibility of growing crops on the Moon,” study leader Sara Santos of the University of Texas said in a statement. “How do we convert this regolith into soil? What kinds of natural mechanisms could cause this conversion?”
When experimenting with lunar regolith, scientists use simulants, which are artificial mixtures designed to be as close to the real thing as possible. This is because samples of actual lunar regolith are rare and scientifically valuable.
In their experiment, Santos’ team added different concentrations of vermicompost to several samples of a simulant based on actual regolith that was brought back to Earth. apollo mission. Vermicompost is a compost produced by red wiggler worms that prefer to decompose biowaste such as food scraps, hygiene products and cotton clothes, recycling them instead of throwing them away.
To some of these samples they also added arbuscular mycorrhizal fungi, or AMF for short, while other samples contained only AMF with no vermicompost, providing a mixture of different abundances for contrast and comparison.
AMF is a fungus commonly found in the Earth’s soil. This has many positive benefits, such as improving the circulation of nutrients in the soil while reducing the abundance of toxic metals, and even producing a protein that helps bind soil particles together, reducing the amount of erosion that occurs.
Santos’ team grew gram plants in all these samples. They also had some chickpeas growing in normal, terrestrial soil that they could use as controls to compare all the regolith-grown chickpea plants to.
Over time, Santos’ team compared the growth of chickpea plants and the volume and weight of their seeds in different samples. They found that chickpea plants only flowered and produced seeds in samples that were treated with both vermicompost and AMF, and that contained no more than 75% regolith. Higher concentrations caused severe symptoms of stress in plants.
However, even below 75% regolith, things were not perfect. For example, compared to control plants grown in terrestrial soil, plants in simulants produce fewer seeds. However, the weight of individual seeds of those plants grown with 25–50% vermicompost was equal to that of the control plants. Dry shoot and root mass were also significantly greater in plants grown side by side treated with AMF, suggesting that the presence of AMF was aiding plant growth.
Scientists say that at present it is not clear how suitable the gram grown in regolith is for eating.
“We want to understand their feasibility as a food source,” says Jessica Atkin, Ph.D. candidate at Texas A&M University and lead author of the study said in the statement. “How healthy are they? Do they contain the nutrients astronauts need? If they’re not safe to eat, how many generations will they last?”
Still, the findings lend credence to the idea that crops could one day be grown in lunar regolith to aid astronauts living in a lunar outpost. Indeed, AMF fungi successfully colonized and survived the simulant, suggesting that terrestrial organisms can find a home in lunar regolith.
By better altering the soil-regeneration strategies adopted here by Santos and Atkins’ team, it may also be possible to improve the fertility of the regolith, and over time turn it into a seemingly self-sustaining soil that is rich in organic molecules and microbial life.
The research is described in a paper published March 5 in the journal scientific report.
