OPTIMIZING AGRICULTURE IN SIMULATED INTERPLANETARY SOILS (OASIS)

---

Martian regolith will be useful as a plant substrate for sustainable agriculture. However, Martian surface minerals lack an inherent microbiome, plant essential nutrients, and to date no regolith-based agriculture experiments have been conducted in microgravity. To test how plant-microbe-mineral interactions differ in altered gravity, barley (Hordeum vulgare) seeds will be germinated in a sterilized Martian regolith simulant (JSC-Mars-1) augmented with recycled brewing byproducts to improve the soil’s fertility and structure, and then supplied with microbes to facilitate nutrient transformation and organic matter breakdown. To assess how barley leverages the soil environment in microgravity, the experiment will measure plant nutrition and morphology, recruitment and communication with microorganisms in the rhizosphere using ultra-high resolution mass spectroscopy (FT-ICR-MS), metabolic function of microorganisms (sequencing), along with ecological indicators of the plant-soil system such as greenhouse gases (GHG) and other volatile organic compounds. Microgravity grown plants will be compared to an earth-based control. As barley is ubiquitous in human nutrition around the globe being used for breads, cereals, flour, and beverages, this novel investigation will inform on the feasibility of including barley on future long-term human missions to Mars. 

The breakdown of soil organic matter, nutritional reliance on the soil environment, and regulation of greenhouse gases will be altered in microgravity compared to a terrestrial control. 

Characterize the effect of microgravity on barley nutrition, physiology, and morphology, how barley attracts microorganisms in its rhizosphere and how soil microorganism are functioning, the breakdown of organic matter, and generation of greenhouse gases associated with regolith-based agriculture. 

Evaluation of the use of Martian regolith to support sustainable plant growth in reduced gravity conditions, paving the way for sustainable agricultural practices in Martian colonies.