A large amount of studies has focused on aquatic diatom ecology and their use in the assessment of water quality. Comparatively, much less is known about terrestrial diatoms’ ecological behaviour and sensitivity to environmental factors. In the current DISCO project (Diatoms as Indicators of Soil Conditions) we propose to go further on the exploration of diatoms as indicator of soil conditions combining traditional microscopical approaches and metabarcoding techniques via high-throughput sequencing (HTS). Since soil biodiversity is increasingly under several pressures, interventions to reduce and to monitor the impact of these threats to are available and should be widely adopted. We hypothesise that terrestrial diatom communities can serve as a proxy of anthropogenic disturbance levels as well as indicators of soil fertility. Such method could serve as a tool for implementation of future policies to protect and value soil biodiversity, which are still at an early stage and need further development. We intend to explore the distribution of soil diatoms, delivering new information on the physiographic and environmental parameters that controls and these communities’ distribution patterns. Diatoms will be collected in Luxembourg at sites characterised by different combinations of geological and pedological features, maximizing the effect of land-use in the landscape (agricultural areas, forests, grasslands and industrial zones). Environmental variables related to soil fertility (e.g. pH, phosphates, nitrates, K, Mg, Na, total carbon) and soil management practices (i.e. conventional, biological, low phytopharmaceutical inputs and low nitrogen input) will be assessed simultaneously with the sampling of diatom communities. Traditional (light and scanning electron microscopy) and newly developed cutting-edge approaches (high-throughput sequencing) will be used to a provide an overview on their morphological and taxonomical diversity, their functional importance, how they respond to human impact and how they may be applied as bioindicators in terrestrial systems.