Compositions and methods for reducing nitrogen volatilization of urea fertilizers
A nitrogen stabilizing composition is provided. The composition includes 10% to 18% w/w N-(n-butyl) thiophosphoric triamide (NBPT), a solvent, a light oil, and an emulsifier. Related methods for making liquid nitrogen stabilizing compositions, coated urea fertilizers and liquid urea fertilizer solutions are also provided.
1. A nitrogen stabilizing composition comprising:
10% to 18% w/w N-(n-butyl) thiophosphoric triamide (NBPT);
a solvent comprising N-methyl-2-pyrrolidone (NMP), propylene glycol and ethylene glycol;
1% to 5% w/w vegetable oil; and
1% to 5% sunflower lecithin.
2. A composition according to claim 1 , comprising 30% to 40% w/w of the NMP, 20% to 30% w/w of the propylene glycol and 20% to 30% w/w of the ethylene glycol.
3. A composition according to claim 2 wherein the composition is water-free.
4. A method for making a liquid nitrogen stabilizing composition comprising:
(a) dissolving N-(n-butyl) thiophosphoric triamide (NBPT) in a solvent comprising N-methyl-2-pyrrolidone (NMP), propylene glycol and ethylene glycol; and
(b) adding a vegetable oil and an emulsifier to the mixture from step (a), wherein final concentrations of components in the composition are:
10% to 18% w/w NBPT;
1% to 5% w/w vegetable oil; and
1% to 5% w/w emulsifier.
5. A method according to claim 4 wherein the vegetable oil is canola oil.
6. A method according to claim 4 wherein the emulsifier is sunflower lecithin.
7. A method according to claim 4 further comprising:
(c) adding a surfactant to the mixture of step (b), wherein a final concentration of the surfactant is 1% to 5% w/w.
8. A method according to claim 7 wherein the surfactant is polysorbate 20.