A liquid fertilizer additive composition comprising one or more urease inhibitor(s) and one or more aprotic solvents wherein said aprotic solvent comprises one or more members selected from the group consisting ofa) 2-methoxyethyl ether, b) cyclohexylpyrrolidone, c) 1,3 dimethyl-2-imidazolidinone, d) organo phosphorous liquid hexamethyl phosphoramide, and e) dimethyl sulfoxide;wherein said composition weight percent comprises 45-5% of said urease inhibitor(s) wherein the composition further comprises one or more members selected from the group consisting of flow aids, silicas, surfactants and dyes/colorants. view more

The liquid fertilizer additive composition of claim 1, wherein the composition comprises one or more urease inhibitors selected from the group consisting of aliphatic phosphoric triamide, phosphoramides and N-alkyl thiophosphoric triamides.

The liquid fertilizer additive composition of claim 1, wherein the composition comprises the urease inhibitor N-(n-butyl) thiophosphoric triamide.

The liquid fertilizer additive composition of claim 1, wherein the composition comprises the polar aprotic solvent dimethyl sulfoxide.