Parametric optimization and experimental verification of multi-fertilizer mixing by air blowing and blade stirring based on discrete element simulations.

•Fertilizer distribution depends on the speed at the outlet of the mixing cavity.•Uneven dispersion of fertilizer granules due to directly falling from blade gaps.•Fertilizer mixed by double-blade has lower outlet speed than that of single-blade.•Mixing effect of multi-fertilizers by air blowing & double-blade stirring is best.