The QGIS user group Germany conducts user meetings (Anwendertreffen) also this year, there are even two meetings in parallel (in Detmold and Gelsenkirchen).
QGIS is a free GIS, supporting all kinds of geo data processing, which provides extensive possibilities to be adapted and extended.
QGIS supports the analysis and usage of raster data, e.g. satellite data, and vector data, in agriculture these are field geometries or application maps.