SuMaNu is a thematic platform concerning nutrients and manure management, established “in order to strengthen the impact of projects’ outcomes in the selected thematic field”, especially via better integration of project results and conclusions into policies. The present gap analysis clarifies in this connection gaps between envisaged and realised impacts of seven projects to promote sustainable manure management, and specifies the impeding pitfalls, i.e. shortcomings and weaknesses that have caused the missing impact. The rationale behind the gap analysis is to help the design and implementation of future projects to achieve stronger impact. For this aim, it summarizes knowledge of selected projects' ability to produce results and recommendations and to communicate these to the end users for integration into policies. To conduct the gap analysis, an approach of deductive and theory-testing research was used based on a set of described and classified potential pitfalls in project design and implementation that could potentially lead to gaps between envisaged and realised policy impact of projects. Links between pitfall categories and implementation gaps were tested by the use of empirical data collected during this study. Six typical pitfalls were defined, and ten recommendations selected for the gap analysis. The analysis was as far as possible based on referenced documentation. Key target stakeholders representing Germany, Poland and Denmark as well as the BSR region were interviewed in order to increase the quality of the analysis and secure impartiality of the results.  Generally, there were found gaps between envisaged and realised policy impacts. Out of the six classified pitfalls, not all projects had planned to create policy recommendations or impact among end users. The observed projects performed best with respect to producing planned results, whereas the most common pitfall was the ability to communicate these results. There were found considerable differences between the seven projects’ ability to support policy development and create impacts among end-users. It was among others concluded that projects are more likely to be integrated into policies and be implemented by end users if they adhere to some basic principles: 

1) Objectives are SMART and in line with end-user needs; 

2) Activities match the objectives and lead to the production of the foreseen results; and 

3) Representatives of the administration and the end-users are directly involved in project partnerships and activities.