Establishing functional plant–microbe systems in extraterrestrial substrates is critical for sustainable lunar agriculture. We tested whether manure amendment and Mizuna mustard (Brassica rapa var. ja..
Establishing functional plant–microbe systems in extraterrestrial substrates is critical for sustainable lunar agriculture. We tested whether manure amendment and Mizuna mustard (Brassica rapa var. japonica) rhizosphere activity enhance the metabolic potential of a lunar regolith simulant (LHS-1). Plants were grown in four treatments: Unplanted manure-amended regolith (LRM), planted manure-amended regolith (LRMP), planted unamended regolith (LRP), and soil controls. Plant height and community-level physiological profiles (CLPP; Biolog EcoPlates) were measured to assess growth and metabolic diversity. Mizuna grew best in soil, with modest improvements in LRMP compared to LRP, though regolith treatment differences were not statistically significant. CLPP revealed the highest substrate-use diversity and intensity in LRMP, especially for carbohydrates, amino acids, polymers, and carboxylic acids. Unplanted and unamended treatments displayed reduced activity. Together, manure amendment and rhizosphere processes significantly increased microbial metabolism in regolith, demonstrating a biologically driven pathway to mature inert substrates for extraterrestrial crop cultivation.
