The report describes the modelling of nitrogen and sulfur deposition to terrestrial ecosystems with the LOTOS-EUROS model system for Germany during the years 2009-2011. The method of the modelling and the parameterization of the model are described. The results are assessed and compared to other relevant data. The results for the year 2009 are provided within the ⁠UBA⁠ map-server for assessment processes in licensing projects under the German immission control and nature protection legislation. The report is in English as the executing science organization (TNO) is from the Netherlands. The German wide assessment of eutrophication and acidification is described in part 2 of the report.