Chickpeas Complete Full Life Cycle in Simulated Lunar Soil via Bioremediation

Researchers at Texas A&M University have successfully cultivated chickpea plants through their entire life cycle, from germination to seed production, using a growth medium that simulates lunar regolith. This development addresses a key challenge for extended human missions beyond Earth: establishing self-sufficient food production systems in extraterrestrial environments.

The breakthrough centered on treating the sterile and potentially toxic lunar simulant with two biological amendments: vermicompost and arbuscular mycorrhizal fungi (AMF). The research team, which includes postdoctoral researcher Jessica Atkin and principal investigator Sara Oliviera Santos from the University of Texas Institute for Geophysics, demonstrated that chickpeas could thrive in substrate mixtures containing up to 75% simulated lunar regolith. This marks the first documented instance of a legume crop completing its full reproductive cycle within such a high concentration of extraterrestrial material analog.

The 'Myles' chickpea variety was selected for its compact growth habit and inherent resilience, traits beneficial for cultivation within the limited volume of a spacecraft or habitat. Lunar regolith poses agricultural obstacles, including a lack of organic matter and necessary microorganisms, alongside the presence of abrasive particles and toxic elements. To mitigate these issues, the Texas A&M methodology incorporated vermicompost, derived from earthworm castings, to improve substrate hydraulics, sequester contaminants, and enhance plant stress tolerance.

Additionally, AMF was applied as a seed coating to establish a symbiotic relationship that aids nutrient absorption via the taproot system while helping to sequester heavy metals away from plant tissues. While plants in the simulated environment showed stress compared to terrestrial controls, the fungal treatment extended the stressed plants' lifespan by approximately two weeks over those without the fungal application. This research builds upon previous work, such as studies utilizing actual Apollo mission regolith, by focusing on biological conversion to create a fertile growth medium.

This innovation is vital for the feasibility of Bioregenerative Life Support Systems (BLSS) planned for long-duration lunar habitation, supporting NASA's Artemis mission objectives. Cultivating high-protein food sources like chickpeas in situ can substantially decrease the logistical dependency on mass-intensive resupply missions from Earth. The scientific team notes that further rigorous investigation is required to confirm the complete safety and nutritional profile of the harvested seeds before they can be validated as a viable astronaut food source. The methods developed also present potential applications for reconstructing degraded soils in nutrient-deficient and drought-affected agricultural regions on Earth.