Abstract EANA2025-190

As humanity extends its views to other planets and the idea of terraformation becomes more prevalent, it is crucial to understand the effect of biotic and abiotic processes on mineral dissolution. The Ecotron Ile de France (Ecotron IdF), is a large-scale mesocosm facility that can be used as a test bed for examining these weathering processes. This study examined the effect of alfalfa genotype and fertilization on weathering of basaltic material similar to what could be found in Martian regolith. The Ecotron IdF was prepared with fifteen 75 L columns packed with granular basalt, supporting three different genotypes of alfalfa, one of which was grown under fertilized and unfertilized conditions, along with a control that did not contain plants. Water draining from these soil columns was sampled for mineral analysis to understand the progression of mineral weathering by chemical and plant-driven processes. For each drainage event, water discharge was manually sampled every 24 hours from collection reservoirs. Additionally, for selected events, samples were automatically collected in 2-hour intervals directly from the drainage outlet via an Arduino - UNO R3 auto sampler. The water samples were analyzed using ICP-MS to quantify released lithogenic elements (e.g. Al, Ca, K, Mg, Mn, Na, P, S, Si, Ti). Significant differences were observed in the amount of drainage between control and planted treatments, as well as differences in concentrations of measured elements that became more pronounced over time. Understanding processes of weathering and soil genesis will become vital as we expand beyond Earth and begin to terraform other planetary surfaces.