During 20/06 and 21/06/ 2015 Vilém Pavlů, Renata Hujerová and Lenka Pavlů visited one of the oldest grassland fertilization experiments in Germany (Rengen). It was a regular spring study visit which is based on ten years cooperation between Czech and German colleagues. In the course of the study visit the members of the team collected data concerning ecology of Plantago lanceolata (plant biomass, content of chlorophyll, height measurements….) and soil samples. Finally the topic of next project and finalization of manuscript were discussed with PD Dr. Juergen Schellberg (leader of the experiment, University of Bonn).