A method for the manufacture of a homogeneous, solid, particulate, ammonium-based composition comprising an ammonium salt and an additive in a production plant comprising at least an evaporator unit, a particulation unit, optionally an effluent gas treatment unit comprising a scrubber, and a scrubber solution storage container, optionally a scrubber evaporator, and optionally a mixing unit, wherein the method comprises at least the steps of: (i) in the evaporator unit, concentrating a melt comprising an ammonium salt and water to a melt comprising an ammonium salt and 1 to 5 weight% of water; (ii) optionally, in the mixing unit, mixing the melt comprising an ammonium salt and 1 to 5 weight% of water obtained in step (i) with other components to produce an ammonium-based melt; (iii) in the particulation unit, particulating the melt obtained in step (i) or (ii), thereby obtaining the homogeneous, solid, particulate, ammonium-based composition; (iv) optionally, in the effluent gas treatment unit, treating the effluent gas from the particulation unit comprising ammonia gas with an aqueous solution to produce a scrubber solution; (v) optionally, in the scrubber solution storage container, storing the scrubber solution from the effluent gas treatment unit produced in step (iv); and (vi) optionally, in the scrubber evaporator, concentrating the scrubber solution from the scrubber solution storage container, after which the concentrated scrubber solution is mixed with the melt comprising an ammonium salt and water or added to the melt in the mixing unit of step (ii); characterized in that the additive is introduced as an aqueous suspension, an aqueous dispersion, or an aqueous solution, in any one or more of: (a) the melt comprising an ammonium salt and water before the evaporation unit; (b) the melt comprising an ammonium salt and 1 to 5 weight% of water in the mixing unit; (c) the effluent gas treatment unit; (d) the scrubber solution storage container containing the scrubber solution. (i) in the evaporator unit, concentrating a melt comprising an ammonium salt and water to a melt comprising an ammonium salt and 1 to 5 weight% of water; (ii) optionally, in the mixing unit, mixing the melt comprising an ammonium salt and 1 to 5 weight% of water obtained in step (i) with other components to produce an ammonium-based melt; (iii) in the particulation unit, particulating the melt obtained in step (i) or (ii), thereby obtaining the homogeneous, solid, particulate, ammonium-based composition; (iv) optionally, in the effluent gas treatment unit, treating the effluent gas from the particulation unit comprising ammonia gas with an aqueous solution to produce a scrubber solution; (v) optionally, in the scrubber solution storage container, storing the scrubber solution from the effluent gas treatment unit produced in step (iv); and (vi) optionally, in the scrubber evaporator, concentrating the scrubber solution from the scrubber solution storage container, after which the concentrated scrubber solution is mixed with the melt comprising an ammonium salt and water or added to the melt in the mixing unit of step (ii); (a) the melt comprising an ammonium salt and water before the evaporation unit; (b) the melt comprising an ammonium salt and 1 to 5 weight% of water in the mixing unit; (c) the effluent gas treatment unit; (d) the scrubber solution storage container containing the scrubber solution.