Global organic soils – organic matter quality, carbon and nitrogen stocks and fluxes

We conducted a global survey of soil organic matter formation and transformation processes in organic soils, during the dry season (i.e. the annual water table minimum time of year including temperate and boreal summers) at each site between 2011 and 2022. We used 156 organic soil samples from the top 10 cm in 61 sites in our global organic soil database throughout the rainy tropical, temperate, and boreal climate zones. The main purpose of the dataset is to investigate water-extractable organic matter (WEOM) of soil to determine which ecosystem properties (e.g. temperature, water content, land use, plant carbon inputs, nutrients, respiration or methanogenesis rates) control the persistence of organic matter. We applied ultrahigh-resolution mass spectrometry to analyse molecular species and nominal oxidation state of carbon (NOSC) of WEOM.