Report on bioavailability and agronomic N use efficiency of BBFs across different European climates, crops and soils

Agronomic N use efficiency of a range of current and emerging N containing BBFs to relevant crops under various European climatic conditions is determined based on field trials. Several crop yield parameters (total biomass, product yield, harvest index, N uptake, N harvest index, apparent N recovery ANR) will be determined, from which the BBF N Mineral Fertiliser Replacement Value (MFRV) can be estimated. The ANR and MFRV will be related to BBF properties, e.g. proportion of mineral N present initially or the potential N release rate (determined in task 4.2) of the BBF, to achieve a mechanistic explanation, which allows generalisation of the results also to other BBF than those included in the trials.