Print button

Abstract EANA2024-25


Closing the Loop: Composting Strategies for Nutrient Recycling in Lunar and Mars Agriculture

Anna-Maria Wirth (1,2), Nigel J. Mason (1)
(1) School of Physics and Astronomy, Ingram Building, University of Kent, CT2 7NH, Canterbury, United Kingdom (2) School of Biosciences, Sir Martin Evans Building, Cardiff University, CF10 3AX, Cardiff, United Kingdom


If we are to establish settlements on the Moon and later Mars, we must cultivate our own food in sustainable closed agricultural ecosystems, reducing and later eliminating the reliance on resources transported from Earth. A proof-of-concept study  has been  conducted to develop a potential composting system that can rapidly increase the organic nutrients of Mars/Lunar regoliths which are otherwise naturally devoid of organic matter and microbes that are necessary to optimise plant growth and ‘healthiness’.

The operational hypothesis is that as more plant waste is recycled back into the sterile Mars/Lunar regoliths, the organic content of this regolith increases thus causing an increase in fresh biomass production and ‘healthier’ plants characterized by plant height, root length and leaf colour. Ongoing experiments are being conducted in an isolated, sterile environment within a PHcbi MLR-352H-PE Climate Chamber. The chamber setup follows a day/night cycle and regulates temperature and humidity for consistent and reliable results.

Alfalfa microgreens, with a 7-day germination-to-harvest cycle, were selected for their suitability in short-term experiments involving multiple two-week cycles. Each cycle includes one week of growing and harvesting followed by one week of composting, with post-cycle plant waste being recycled back into the regoliths. To maintain intact plant leaves and root structures during harvesting, watering is stopped one day prior. This ensures the regoliths remain less compact and are more pliable.

The expected results are that as the more plant waste is being recycled back into the regoliths, the organic content increases causing an increase in harvested biomass and pre-characterised ‘healthier’ plants. Germination rate is also expected to increase. The envisaged subsequent research will aim to broaden the methodology by developing a dependable irrigation system [1] for the plants to minimise fluctuations within the controlled environments for plants. Furthermore, investigations will explore the integration of various microbiomes and physical decomposers (e.g. earthworms) into regoliths to mitigate biocontamination and establish a self-sustaining composting system resembling terrestrial horticultural practices, wherein soil fertilisation precedes planting [2].

 

References:

[1]  Kotzen, B., Paradelo, M. and Fruscella, L. 2024. Ecocycles 10(1), pp. 1–17.

[2] Wamelink, G.W. & Schug, Line & Frissel, Joep & Lubbers, Ingrid. Open Agriculture. 7. 238-248. (2022).