Method of forming an encapsulated fertilizer that includes the step of providing a core particle. The core particle includes a fertilizer and has an outer surface. The method further includes the step of applying an isocyanate component directly to the outer surface of the core particle. The isocyanate component has isocyanate functional groups. The method further includes the step of reacting the isocyanate component with ambient moisture to form a layer disposed about the core particle to form the encapsulated fertilizer. The layer includes polyurea linkages and may further include polyurethane linkages.