Abstract EANA2025-131

Ever since humans realized that the Earth is surrounded by a vast, infinite space with countless stars, planets, moons and other celestial bodies, the dreams of future human colonization of the outer space emerged.

However, what used to be restricted to the fantasies and visions of sci-fi authors is becoming more and more actual in recent years. With the advancements in technology and space exploration, the thoughts of establishing a permanent, or at least long-term settlements on other Solar system bodies, like Mars or the Moon, have been getting a lot of scientific attention. Naturally, supporting manned crews on the surface of Mars or Moon brings a lot of obstacles and challenges. One of the fundamental tasks will be securing of the basic needs of the crew, such as food or oxygen. Since bringing supplies from the Earth would be costly and problematic, the In situ resource utilization concept promotes usage of local materials for production of as many things for the mission as possible – habitats, materials, tools, devices – and even food. Considering the latter, direct cultivation of crops in the lunar regolith comes as a solution for on-site food production.

Addressing this issue, we have conducted a cultivation experiment with lettuce (Lactuca sativa), grown in lunar regolith analogue from Antarctica (characterized and tested in previous experiments) with and without addition of biochar (70:30 regolith:biochar), watered with distilled water/Hoagland nutrient solution, in order to evaluate the potential and limitations of lunar regolith as a substrate for lunar agriculture. Lettuce plants were cultivated for 4 weeks in growth chamber with stable light and temperature conditions.

The plant response to the inherently toxic effect of the regolith, as well as the hypothesised alleviating action of the biochar addition were evaluated by several approaches in parallel. The photosynthetic performance and stress-induced decline in photosynthesis was determined by a set of chlorophyll fluorescence parameters, including FV/FM (potential yield of photochemical photosynthetic processes), ФPSII (effective quantum yield of photosystem II) and NPQ (non-photochemical quenching). The growth rate was assessed by monitoring the leaf area development over time and total biomass comparison at the end of the experiment. Additionally, the edible parts of the plants (shoots) were analysed for the content of heavy metals and antioxidants.