Internship at NMI (Nutrient management institute)

By Jihane Mahdi

Figure 1: Application of the thick fraction with different additives to the plots of the field experiment

Last June-July I had the opportunity to conduct my internship at NMI under the supervision of the Senior project manager Debby van Rotterdam. During this internship I have joined mainly the activities of the “Separated withe value” project related to the CAP pilot peat meadows. It is a project aiming at optimizing the application of dairy manure’s thick fraction from source separation floors to peat meadows. Two main issues are addressed with this project: finding an optimal perspective to the use of the tick fraction newly emerging from ammonia reduction floors, and providing ecosystem services (carbon sequestration, preserve/improve surrounding biodiversity and soil/water quality) to wetted peat meadows that have increasingly higher water levels. The optimization of the thick fraction-use concerns additives (types and mixing levels), processing, and field application.

The project has an incubation experiment and two years field seasons planned. I have participated in development and execution of the incubation experiment (figure 2) and in the preparation of the field experiment (figure 1).

Figure 2: Set up of the incubation experiment

The purpose of the incubation was to simulate the production/storage of the fertilizers from the thick manure fraction. We made different preparations with additives to manure and put them in pvc columns leaving a headspace for gas accumulation. The gas concentrations (N2O, CH4, CO2 and NH3) was then measured using a photoacoustic gas analyzer for six weeks. The change in composition and weight of the manure fractions were also monitored.

The internship was concluded with a presentation to the NMI team and the ‘’separated with value’’ project members (including farmers) about the results of the experiment. Some insightful results and recommendations were concluded, which will be shared with farmers in a report and joint scientific paper in the future.