Livestock manure management, especially related to the soil fertilisation practice, is responsible for most of the emissions in agriculture. These include ammonia emissions (NH₃) which, together with other nitrogen forms such as nitrate ions (NO3-), play a key role in environmental problems, affecting water, soil and air quality. Within the digital agriculture framework, monitoring of manure spreading through Earth Observation data could provide relevant information both to mitigate pollutants emission, and in agricultural practice management. Objective of the activity is to present a GIS-based tool on an Open-Source platform, developed for susceptibility estimation of sewage spreading occurrence in agricultural areas. The tool is based on the analysis of multispectral and hyperspectral satellite time series at various resolutions, in synergy with field data and ancillary information collected from regional repositories, to produce a series of classified and prioritised spatially explicit information. Spectral analysis of satellite acquisitions has been performed, thus enabling the semi-automatic identification of manure spreads through a classification process based on specific indices defined ad hoc; information on most relevant manure sources in the area such as farm and biodigester has been selected. Field campaigns from October to March were carried out to validate the spreading event. Po plain, (wide agricultural region in Italy) has been selected as a case study to demonstrate the ability of the proposed tool in supporting the monitoring of manure spreading. Therefore, a good agreement was found between the results obtained with the susceptibility map, applying the GIS-based tool, and the areas detected.