Digestates are a key issue for the anaerobic digestion plants management. Indeed these residues from the digestion represent volumes comparable to the volumes of treated inputs and have to be properly valorized in order to ensure good environmental and economic performance of the whole biological treatment scheme. Digestates are generally used as soil improvers or organic fertilisers on cropped soils. Nevertheless the quality of the applied product is largely influenced by the type of organic resources treated in the digester and by the post-processing (phase separation, composting or drying of the solid phase, membrane filtration of the liquid phase, ammonia concentration, etc.). Moreover the way of post-processing and the quality of the final digestate product will influence the environmental impacts after their application. The proposed work aimed at characterizing the quality of different types of digestates and at obtaining mass balances of organic matter and nutrients along post-processing and after spreading. The presented results focus on the fate of nitrogen which is one of the most important nutrients found in digestate.