Scientists have managed to grow chickpeas in lunar soil, a fact very similar to Andy Weir’s novel The Martian, which takes us to a near future where space exploration has reached unprecedented levels. The plot revolves around astronaut and botanist Mark Watney, played by Matt Damon, who finds himself alone on Mars due to his fate.
Using ingenuity and scientific knowledge of botany, Watney managed to grow potatoes in the harsh terrain of Mars to survive in an unfamiliar environment. This plot, a combination of science and fiction, makes us ask: Is it really possible to grow plants on alien soil? Surprisingly, the answer is closer to reality than we think. But instead of potatoes there were chickpeas and instead of Martian soil there was lunar soil.
Lunar soil, dry and strange land
Lunar soil, or lunar regolith, consists primarily of rock fragments and dust with a unique composition, formed by meteorite impacts over billions of years. It is rich in minerals but also in heavy metals, and unlike the rich soils of many terrestrial ecosystems, which are full of vital nutrients and microorganisms, the soil on the lunar surface is a completely sterile substrate.
These components, which are not found on the Moon, are essential for the growth, health and resilience of plants to adverse conditions.
Since the first Apollo missions returned lunar soil samples, there have been many attempts to grow plants in this soil or simulated versions of it. In 2022, researchers Anna-Lisa Paul, Steven Elardo and Robert Ferl from the University of Florida attempted to breed the plant Arabidopsis thalianaone of the most commonly used model plants in the laboratory.
The results, published in the specialist journal Communication biologymagazine dependent Natureshowed that plants growing on lunar soil showed very poor growth and severe symptoms of stress.
Chickpeas from lunar regolith
Scientists Jessica Atkin of Texas A&M University and Sara Oliveira Santos of Brown University investigated the feasibility of growing chickpeas in simulated lunar soil, a substrate created on Earth but with the same physicochemical properties as the original. But like Mark Watney, they decided to help the plants so it wasn’t just lazy soil.
They added some vermicompost to the lunar regolith. Vermicompost is an organic fertilizer rich in nutrients and microorganisms, obtained from the decomposition of organic matter by worms. The production of this material is very simple and can be done without large amounts of material.
In a hypothetical mission, dehydrated microorganisms and worms could be transported into captivity and vermicompost made from food scraps and other organic waste. A constant supply of these raw materials is not necessary, they are only necessary to start the process and as the plant grows, the same leaves and dead parts are used to continue the process.
Mycorrhizal fungi were also used. This type of organism forms a symbiotic relationship with the roots of plants, especially legumes such as chickpeas, improving their nutrient absorption and stress resistance.
These fungi can initially be transmitted in the culture medium or with live plants that transmit mycorrhizae to newly germinated seeds.
Scientists say that by combining mycorrhiza and compost, they have managed to grow chickpeas in a controlled environment similar to conditions on the moon.
Although the plants showed signs of stress, this experiment was an advance on previous research Arabidopsis. However, scientists emphasize the need to adapt the process to reduce plant stress.
Alien crops pose a challenge to agriculture
Growing crops on the Moon or Mars is fraught with insurmountable difficulties, primarily due to the lack of a suitable atmosphere (Mars has an atmosphere, but it is inhospitable) and harsh environmental conditions. To overcome these obstacles, special devices are required to control air pressure, humidity, temperature and air composition; something that has been done in many laboratories and is not a problem in places outside our planet.
If the research results of Atkin and Oliveira Santos are confirmed, it will be possible, under properly controlled conditions, to grow plants in future bases on the Moon or Mars without having to transport them or move large amounts of terrestrial soil. All you need is spores of microorganisms, worms, organic matter and mycorrhizal cultures to make vermicompost and improve lunar soil.
This would be a way to reduce dependence on Earth for the supply of substrates and raw materials while minimizing the amount of cargo that must be carried on manned research expeditions and extending their stay without resupply. Just like Mark Watney did on Mars.
References:
- Atkin, JA et al. 2024. From Dust to Seed: A Moon Chickpea Story. bioRxiv.
- Paul, A.-L. et al. 2022. Growth and gene expression of Arabidopsis thaliana under simulated lunar regolith. Communication biology, 5(1), 1-11.
With information from: