The invention relates to a solid, particulate, urea-based blend composition comprising a urea-based compound in particulate form, one or more components in particulate form, selected from the group of nitrates, phosphates, sulphates and chlorides, and a urease inhibitor of the type phosphoric triamide, in particular N-(n-butyl) thiophosphoric triamide (nBTPT), wherein the urea-based blend composition is further characterized in that it comprises one or more reactive alkaline or alkaline-forming inorganic or organic compounds. The composition according to the invention has been stabilized against the degradation of a urease inhibitor of the type phosphoric triamide, in particular N-(n-butyl) thiophosphoric triamide (nBTPT). The invention further relates to a method for the manufacture of the claimed solid, particulate, urea-based blend composition.
