FERTIRIS 21 DCD is a simple liquid nitrogen fertilizer in which the function of the nutrient nitrogen (urea and ammonia) has been linked to SULPHUR and DICIANDIAMMIDE so as to achieve positive economic and environmental management advantages of this macro-nutrient relative to biological transformation processes. Through the combination of SULPHUR with the inhibitor DICIANDIAMMIDE, ammonia nitrogen is fixed and made available for a period of 8 to 12 weeks by reducing the traditional nitrogen supply. The inhibitory activity of DICIANDIAMMIDE against urease and nitrifying bacteria is manifested in reduced losses by leaching and volatilization. The inhibitory action of DICIANDIAMMIDE, exhibits absolute invariance with respect to environmental conditions, and this, together with the ease of use, makes FERTIRIS 21 DCD a decidedly attractive product compared to other similar compounds, in that the nitrogen distributed is completely absorbed by the affected crop. FERTIRIS 21DCD is a product designed specifically for effective use in spring nitrogen fertilization of rice carried out in conjunction with weed control or fungicide and insecticide treatments.