GRANULAR UREA-BASED FERTILIZER

摘要

An improved homogenous granular fertilizer composition is disclosed; the composition is comprised primarily of urea, N-(n-butyl)thiophosphoric triamide (NBPT), and dicyandiamide (DCD). The composition of this invention can be applied to a field crop in a single surface application and will nevertheless supply sufficient nitrogen to the plants throughout their growth and maturing cycles. The new improved composition increases the nitrogen uptake by plants, enhances crop yields, and minimizes the loss of both ammonium nitrogen and nitrate nitrogen from the soil. The NBPT is incorporated into the homogenous granular fertilizer composition of this invention by blending a concentrated solution of NBPT in a solvent selected from the group consisting of liquid amides, 2-pyrrolidone, and N-alkyl 2-pyrrolidones directly into molten urea prior to its granulation; the DCD may be added to the urea melt as a solid or in dissolved form along with the NBPT.