Extruded fertilizer granules with urease and/or nitrification inhibitors
Fertilizers with urease inhibitors and/or nitrification inhibitors are described. The fertilizer can include an extruded granule containing urea, a polymeric binder, and a nitrification inhibitor and/or an urease inhibitor.
1. An extruded fertilizer granule comprising an extrudate having:
solid urea;
one or more nitrification or urease inhibitor(s) or a combination thereof; and
a polymeric binder having a melting point of less than 80° C., the polymeric binder comprising 20 wt. % to 30 wt. % of one or more of polyethylene glycol, polycaprolactone, or a combination of polyethylene glycol and polycaprolactone, where the wt. % is based on the weight of the fertilizer granule,
wherein the extrudate is bound together by the polymeric binder and the extruded fertilizer granule does not contain a coating on the extrudate.
2. The extruded fertilizer granule of claim 1 , wherein the extrudate comprises by weight of the extrudate:
40 wt. % to 80 wt. % of the solid urea;
20 wt. % to 40 wt. % of the binder; and
0.02 wt. % to 10 wt. % of one or more nitrification and/or urease inhibitor(s).
3. The extruded fertilizer granule of claim 1 , wherein the extrudate comprises:
0.02 wt. % to 0.5 wt. % of the urease inhibitor; and/or
0.5 wt. % to 10 wt. % of the nitrification inhibitor.
4. The extruded fertilizer granule of claim 1 , wherein at least one of the urease inhibitor(s) comprises N-(n-butyl) thiophosphoric triamide and/or wherein at least one of the nitrification inhibitor(s) comprises dicyandiamide.
5. The extruded fertilizer granule of claim 1 , wherein the polymeric binder is biodegradable and/or water soluble.
6. The extruded fertilizer granule of claim 1 , wherein the solid urea is powdered urea.
7. The extruded fertilizer granule of claim 1 , further comprising micronutrients.
8. The extruded fertilizer granule of claim 1 , wherein the extrudate has a diameter of 1 mm to 4 mm.
9. The extruded fertilizer granule of claim 1 , wherein the polymeric binder is polyethylene glycol.
10. A fertilizer composition comprising a mixture of:
(a) urea granules; and
(b) a plurality of the extruded fertilizer granules of claim 1 .
11. A process for producing a fertilizer, the process comprising:
extruding a composition comprising solid urea, a polymeric binder having a melting point of less than 80° C., and one or more nitrification or urease inhibitor(s) or a combination thereof at an extrusion temperature sufficient to melt the polymeric binder and form an extrudate that is bound together by the polymeric binder; and
forming a fertilizer granule from the extrudate,
wherein the polymeric binder comprises 20 wt. % to 30 wt. % of one or more of polyethylene glycol, polycaprolactone, or a combination of polyethylene glycol and polycaprolactone, where the wt. % is based on the weight of the fertilizer granule.
12. The process for producing a fertilizer of claim 11 , wherein the extrudate comprises:
40 wt. % to 80 wt. % of the solid urea;
20 wt. % to 40 wt. % of the polymeric binder; and
0.02 wt. % to 10 wt. % of one or more nitrification and/or urease inhibitor(s).
13. The process for producing a fertilizer of claim 11 , wherein the extrudate comprises:
0.02 wt. % to 0.5 wt. % of the urease inhibitor; and/or
0.5 wt. % to 10 wt. % of the nitrification inhibitor.
14. The process for producing a fertilizer of claim 11 , wherein at least one of the urease inhibitor(s) comprises N-(n-butyl) thiophosphoric triamide and/or wherein at least one of the nitrification inhibitor(s) comprises dicyandiamide.
15. The process for producing a fertilizer of claim 11 , wherein the polymeric binder is biodegradable and/or water soluble.
16. The process for producing a fertilizer of claim 11 , wherein the solid urea is powdered urea.
17. The process for producing a fertilizer of claim 11 , wherein the fertilizer granule has an average diameter of 1 mm to 4 mm.
18. The process for producing a fertilizer of claim 11 , wherein:
the extrusion temperature is less than 80° C.; and
the extrudate is extruded from a co-rotating twin screw extruder.
19. The process for producing a fertilizer of claim 11 , further comprising combining a plurality of the fertilizer granules with added urea granules to form a blended fertilizer such that the added urea granules are not bound in the extrudate of the fertilizer granules.
20. The process for producing a fertilizer of claim 11 , wherein the polymeric binder is polyethylene glycol.