Plan nutrition is an important input in Swedish crop production, both from a cost effectiveness point of view and from a crop value point of view regarding both quality and yield. To optimize the usage of plant nutrition is therefore of great importance for a profitable crop production. Furthermore, plant nutrition also relates to environmental issues, including eutrophication. This makes the usage a target for legislation, which in the end also has great impact on the crop grower. Hence, there is a need to produce more knowledge to provide guidance in plant nutrition matters, from a crop production point of view and from an environmental point of view. In addition to the purpose of the field trials to provide new knowledge for production and legislation, they also pursue an educational purpose. Exhibition of the trails during growing season and advising afterwards is an effective tool for raising the interest of crop nutrition among growers.