This dataset encompasses the data collected and processed during the citizen science project “Soil Watchers” (“Vigilantes del Suelo”), conducted by Fundación Ibercivis and CITA in Spain during 2023-2024. Project Overview “Soil Watchers” engages participants through citizen science campaigns to collect soil samples from their surroundings and analyse them to assess their health. The results from each area contribute to creating a national map of soil health. Target Audience Throughout the course of the project, we conducted two soil collection and analysis campaigns: A campaign aimed at secondary school students from educational centres across Spain. An open campaign targeted at collecting data from rural soils, encouraging participation from a broader, more adult audience, including senior citizens. Tools and Methods Participants in “Soil Watchers” are provided with a kit for collecting and analysing soil samples. The results can be hosted and geo-referenced through a mobile application, contributing to the creation of a national soil quality map. Individual participation in “Soil Watchers” is facilitated by purchasing the project’s kit, detailed in the protocol guide. Analysis data can be stored and shared via the Geonity App, available from December 2023. This mobile application includes the “Soil Watchers” project and contributions from all participants. Cities of Engagement Eight Spanish cities – Málaga, Madrid, Zaragoza, Castellón, Burgos, Villanueva de la Serena, A Coruña, and Ciudad Ciencia (CSIC for national deliveries) – serve as ambassadors for “Soil Watchers,” aiding in the distribution of measurement kits to participants.