High temperature amine-stabilized DCD and/or alkyl thiophosphoric triamide solvent systems and use in agricultural applications

Abstract

An inhibitor composition contains alkyl thiophosphoric triamide (or a mixture of alkyl thiophosphoric triamide and dicyandiamide), dissolved in a liquid medium comprising at least one organic solvent and at least one amine stabilizer, is useful in making fertilizer compositions and in a method of fertilizing target plants.

Claims

1. A high temperature stable liquid agricultural composition comprising: 45 wt. % to 55 wt. % of N-(n-butyl)-thiophosphoric triamide (NBPT); dimethylsulfoxide; 1 wt. % to 5 wt. % of a stabilizer consisting of (methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate, and optionally, at least one solvent selected from the group consisting of: (a) at least one dioxolane compound of formula (I.b): ##STR00014## wherein R.sub.6 and R.sub.7 individually comprises a hydrogen, an alkyl group, an alkenyl group, or a phenyl group, wherein n is an integer of from 1 to 10; b) at least one dibasic ester; c) at least one compound of formula (III):
R.sub.3OOC-A-CONR.sub.4R.sub.5(III), wherein R.sub.3 comprises a C.sub.1-C.sub.36 alkyl group; wherein R.sub.4 and R.sub.5 individually comprise a C.sub.1-C.sub.36 alkyl group, wherein R.sub.4 and R.sub.5 can optionally together form a ring; and wherein A is a linear or a branched divalent C.sub.2-C.sub.6 alkyl group; d) at least one alkyldimethylamide; e) at least one alkyl lactate; f) ethyl levulinate; g) at least one alkyoxyalcohol, ether alcohol, or alcohol; h) at least one glycerine or glycerine derivative; i) at least one alkylene carbonate; and j) organophosphate of formula (I.a): ##STR00015## wherein R.sub.1, R.sub.2 and R.sub.3, are each independently chosen from a C.sub.1-C.sub.16 alkyl group, a C.sub.1-C.sub.16 alkenyl, group, a C.sub.1-C.sub.16 alkoxyalkyl group, a C.sub.7-C.sub.30 alkylarylalkyl group, a C.sub.7-C.sub.30 arylalkyl group, or an aryl group; and wherein the wt. % are based on a total weight of the composition.

2. The liquid agricultural composition of claim 1, wherein the stable liquid agricultural composition consists of 45 wt. % to 55 wt % of the N-(n-butyl)-thiophosphoric triamide (NBPT), and at least 2 wt. % to less than 3 wt. % of the stabilizer consisting of the (methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate, and optionally the at least one solvent, wherein the wt. % are based on a total weight of the composition; and the dimethylsulfoxide.

3. The liquid agricultural composition of claim 1, wherein the N-(n-butyl)-thiophosphoric triamide (NBPT) is present in an amount between 45 wt. % and less than about 50 wt. %, based on a total weight of the composition.

4. The liquid agricultural composition of claim 1, wherein the stabilizer is present in an amount between 1 wt. % and 3 wt. % based on a total weight of the composition.

5. The liquid agricultural composition of claim 1, wherein the at least one solvent is present and comprises the organophosphate of formula (I.a): ##STR00016## wherein R.sub.1, R.sub.2 and R.sub.3, are each independently chosen from a C.sub.1-C.sub.16 alkyl group, a C.sub.1-C.sub.16 alkenyl, group, a C.sub.1-C.sub.16 alkoxyalkyl group, a C.sub.7-C.sub.30 alkylarylalkyl group, a C.sub.7-C.sub.30 arylalkyl group, or an aryl group.

6. A method of stabilizing a liquid fertilizer composition at high temperatures comprising contacting one or more nitrogenous fertilizer compounds with the high temperature stable liquid agricultural composition of claim 1.

7. The method of claim 6, wherein the N-(n-butyl)-thiophosphoric triamide (NBPT) is present in an amount between 45 and 50 wt. % by weight of the liquid inhibitor composition.

8. A concentrated liquid fertilizer composition comprising, based on 100 parts by weight of the composition: (a) up to about 99 parts by weight of one or more nitrogenous fertilizer compounds, and (b) the high temperature stable liquid agricultural composition of claim 1.

9. The concentrated liquid fertilizer composition of claim 8, wherein the at least one said solvent is: at least one dioxolane compound of formula (II.b): ##STR00017## wherein R.sub.6 and R.sub.7 individually comprises a hydrogen, an alkyl group, an alkenyl group, or a phenyl group, wherein n is an integer of from 1 to 10.

10. The concentrated liquid fertilizer composition of claim 8, wherein the at least one said solvent is: at least one dioxolane compound of formula (II.b) ##STR00018## wherein R.sub.6 and R.sub.7 individually comprises a hydrogen, an alkyl group, an alkenyl group, or a phenyl group, wherein n is an integer of from 1 to 10; and organophosphate of formula (I.a): ##STR00019## wherein R.sub.1, R.sub.2 and R.sub.3, are each independently chosen from a C.sub.1-C.sub.16 alkyl group, a C.sub.1-C.sub.16 alkenyl, group, a C.sub.1-C.sub.16 alkoxyalkyl group, a C.sub.7-C.sub.30 alkylarylalkyl group, a C.sub.7-C.sub.30 arylalkyl group, or an aryl group.

11. The concentrated liquid fertilizer composition of claim 8, wherein the at least one said solvent is organophosphate of formula (I.a): ##STR00020## wherein R.sub.1, R.sub.2 and R.sub.3, are each independently chosen from a C.sub.1-C.sub.16 alkyl group, a C.sub.1-C.sub.16 alkenyl, group, a C.sub.1-C.sub.16 alkoxyalkyl group, a C.sub.7-C.sub.30 alkylarylalkyl group, a C.sub.7-C.sub.30 arylalkyl group, or an aryl group.

12. A high temperature stable liquid agricultural composition comprising: 45 wt. % to 55 wt. % of N-(n-butyl)-thiophosphoric triamide (NBPT); 1 wt. % to 5 wt. % of a stabilizer consisting of (methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate, and optionally, at least one solvent selected from the group consisting of: (a) at least one dioxolane compound of formula (I.b): ##STR00021## wherein R.sub.6 and R.sub.7 individually comprises a hydrogen, an alkyl group, an alkenyl group, or a phenyl group, wherein n is an integer of from 1 to 10; b) at least one dibasic ester; c) at least one compound of formula (III):
R.sub.3OOC-A-CONR.sub.4R.sub.5(III), wherein R.sub.3 comprises a C.sub.1-C.sub.36 alkyl group; wherein R.sub.4 and R.sub.5 individually comprise a C.sub.1-C.sub.36 alkyl group, wherein R.sub.4 and R.sub.5 can optionally together form a ring; and wherein A is a linear or a branched divalent C.sub.2-C.sub.6 alkyl group; d) at least one alkyldimethylamide; e) at least one alkyl lactate; f) ethyl levulinate; g) at least one alkyoxyalcohol, ether alcohol, or alcohol; h) at least one glycerine or glycerine derivative; i) at least one alkylene carbonate; and j) organophosphate of formula (I.a): ##STR00022## wherein R.sub.1, R.sub.2 and R.sub.3, are each independently chosen from a C.sub.1-C.sub.16 alkyl group, a C.sub.1-C.sub.16 alkenyl, group, a C.sub.1-C.sub.16 alkoxyalkyl group, a C.sub.7-C.sub.30 alkylarylalkyl group, a C.sub.7-C.sub.30 arylalkyl group, or an aryl group; and wherein the wt. % are based on a total weight of the composition, and no dimethylsulfoxide is present in the composition.

13. The liquid agricultural composition of claim 12, wherein the stable liquid agricultural composition consists of: 45 wt. % to 55 wt % of N-(n-butyl)-thiophosphoric triamide (NBPT), 2 wt. % to less than 3 wt. % of the stabilizer; and the at least one solvent.

14. The liquid agricultural composition of claim 13, wherein the at least one solvent is present and consists of at least one dioxolane compound of formula (II.b): ##STR00023## wherein R.sub.6 and R.sub.7 individually is a hydrogen, an alkyl group, an alkenyl group, or a phenyl group, wherein n is an integer of from 1 to 10.

15. A method of stabilizing a liquid fertilizer composition at high temperatures comprising contacting one or more nitrogenous fertilizer compounds with the high temperature stable liquid agricultural composition of claim 12.

16. The method of claim 15, wherein the stabilizer is present at least 2 to less than 3 wt. %.

17. The method of claim 15, wherein the stabilizer is present in an amount between 1 wt. % and 3 wt. %.

18. The method of claim 15, wherein the stabilizer is present in an amount between 2 wt. % and 3 wt. %.

19. A method of making a solid or concentrated liquid fertilizer composition comprising contacting one or more nitrogenous fertilizer compounds with the high temperature stable liquid agricultural composition of claim 1.

20. The method of claim 19, wherein the solvent comprises at least one member of the group consisting of: organophosphate of formula (I.a): ##STR00024## wherein R.sub.1, R.sub.2 and R.sub.3, are each independently chosen from a C.sub.1-C.sub.16 alkyl group, a C.sub.1-C.sub.16 alkenyl, group, a C.sub.1-C.sub.16 alkoxyalkyl group, a C.sub.7-C.sub.30 alkylarylalkyl group, a C.sub.7-C.sub.30 arylalkyl group, or an aryl group and at least one dioxolane compound of formula (II.b): ##STR00025## wherein R.sub.6 and R.sub.7 individually comprises a hydrogen, an alkyl group, an alkenyl group, or a phenyl group, wherein n is an integer of from 1 to 10.

21. The method of claim 19, wherein the liquid inhibitor composition consists of: 45 wt. % to 55 wt. % of the N-(n-butyl)-thiophosphoric triamide (NBPT), and at least 2 wt. % to less than 3 wt. % of the stabilizer.

22. A high temperature stable liquid agricultural composition consisting of: at least one urease inhibitor, wherein the urease inhibitor is N-(n-butyl)-thiophosphoric triamide (NBPT); dimethylsulfoxide; and at least one stabilizer, wherein said stabilizer is 2-(2-aminoethoxy) ethanol.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a photograph of Several amines or amides were tested to check if they can stabilize NBPT degradation at high temperatures (at greater than 45 C.) in NBPT/DMSO formulation. Each sample was prepared with 2% of amine stabilizer added.

(2) FIG. 2 is a photograph showing the results from 10 weeks storage of 2% monoethanolamine in 1:1 NBPT:DMSO at two different temperatures, 45 C. and Room Temperature (20 C.).

(3) FIG. 3. is a chart of the degradation product, i.e., dimethyl sulfide (DMS) in parts per million (ppm), measured at varying high temperatures for a period of weeks. The results indicate the liquid fertilizer composition with the amine stabilizer exhibited higher stability over time versus a liquid fertilizer composition without the stabilizer.

DETAILED DESCRIPTION

(4) As used herein, the term alkyl means a saturated straight chain, branched chain, or cyclic hydrocarbon radical, including but not limited to, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, t-butyl, pentyl, n-hexyl, and cyclohexyl.

(5) As used herein, the term aryl means a monovalent unsaturated hydrocarbon radical containing one or more six-membered carbon rings in which the unsaturation may be represented by three conjugated double bonds, which may be substituted one or more of carbons of the ring with hydroxy, alkyl, alkenyl, halo, haloalkyl, or amino, including but not limited to, phenoxy, phenyl, methylphenyl, dimethylphenyl, trimethylphenyl, chlorophenyl, trichloromethylphenyl, aminophenyl, and tristyrylphenyl.

(6) As used herein, the term alkylene means a divalent saturated straight or branched chain hydrocarbon radical, such as for example, methylene, dimethylene, trimethylene.

(7) As used herein, the term alkoxyl means an oxy radical that is substituted with an alkyl group, such as for example, methoxyl, ethoxyl, propoxyl, isopropoxyl, or butoxyl, which may optionally be further substituted on one or more of the carbon atoms of the radical.

(8) As used herein, the term alkoxyalkyl means an alkyl radical that is substituted with one or more alkoxy substituents, more typically a (C.sub.1-C.sub.22)alkyloxy-(C.sub.1-C.sub.6)alkyl radical, such as methoxymethyl, and ethoxybutyl.

(9) As used herein, the term alkenyl means an unsaturated straight or branched hydrocarbon radical, more typically an unsaturated straight, branched, (which, in one particular embodiment, is C.sub.1-C.sub.75) hydrocarbon radical, that contains one or more carbon-carbon double bonds, such as, for example, ethenyl, n-propenyl, iso-propenyl.

(10) As used herein, the term arylalkyl means an alkyl group substituted with one or more aryl groups, more typically a (C.sub.1-C.sub.18)alkyl substituted with one or more (C.sub.6-C.sub.14)aryl substituents, such as, for example, phenylmethyl, phenylethyl, and triphenylmethyl.

(11) As used herein, the term aryloxy means an oxy radical substituted with an aryl group, such as for example, phenyloxy, methylphenyl oxy, isopropylmethylphenyloxy.

(12) As used herein, the terminology (C.sub.r-C.sub.s) in reference to an organic group, wherein r and s are each integers, indicates that the group may contain from r carbon atoms to s carbon atoms per group.

(13) Dicyandiamide is a known compound according to formula (I.b):

(14) ##STR00005##

(15) Dicyandiamide, also known as 2-cyanoguanidine, is typically made by treating cyanamide with base and is commercially available.

(16) In one embodiment, the compositions according to the present invention comprise a urease inhibitor, such as an alkyl thiophosphoric triamide or ammonium thiosulfate, a nitrification inhibitor, or a combination of both a urease inhibitor and a nitrification inhibitor.

(17) In one embodiment, alkyl thiophosphoric triamide is N-(n-butyl)-thiophosphoric triamide (NBPT). The at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at a lower range of 2% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at a lower range of 3% by weight of the composition. The at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at a lower range of 5% by weight of the composition.

(18) In another embodiment, at least one of alkyl thiophosphoric triamide and/or dicyandiamide can be present in the liquid agricultural composition at a lower range of 0.5%, or 1%, or 2%, or 3%, or 4%, or 5%, 6%, or 8%, or 10% or 12% or 14%, by weight of the composition. The at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 75%, or 65%, or 60% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 60% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 55% by weight of the composition. In another embodiment, at least one of alkyl thiophosphoric triamide and/or dicyandiamide can be present in the liquid agricultural composition at an upper range of 59%, or 57%, or 55% or 53% or 50%, by weight of the composition. In another embodiment, at least one of alkyl thiophosphoric triamide and/or dicyandiamide can be present in the liquid agricultural composition at an upper range of 48%, or 46%, or 45% or 42% or 40%, by weight of the composition.

(19) In some embodiments, the dibasic ester or blend of dibasic esters comprises adducts of alcohol and linear diacids, the adducts having the formula (IV):
ROOC-A-COOR(IV)

(20) wherein R is an alkyl group (e.g., methyl, ethyl, etc.) and A is a mixture of (CH2)4-, (CH2)3, and (CH2)2-. In other embodiments, the blend comprises adducts of alcohol, typically ethanol, and linear diacids, the adducts having the formula R1-OOC-A-COOR2, wherein at least part of R1 and/or R2 are residues of at least one linear alcohol having 4 carbon atoms, and/or at least one linear or branched alcohol having at least 5 carbon atoms, and wherein A is a divalent linear hydrocarbon. In some embodiments A is one or a mixture of (CH2)4-, (CH2)3, and (CH2)2-. In other embodiments, the dibasic ester comprises adducts of an alcohol and linear or branched diacids, the adducts having the formula (IV): ROOC-A-COOR, wherein R is an alkyl group (e.g., methyl, ethyl, etc.) and A one of the following: (CH2)4-, (CH2)3, (CH2)2-, CH2-, or any mixture thereof.

(21) Dibasic esters of the present invention may be derived from one or more by-products in the production of polyamide, for example, polyamide 6,6. In one embodiment, the at least one dibasic ester comprises a blend of linear or branched, cyclic or noncyclic, C1-C20 alkyl, aryl, alkylaryl or arylalkyl esters of adipic diacids, glutaric diacids, and succinic diacids. In another embodiment, the composition comprises a blend of linear or branched, cyclic or noncyclic, C1-C20 alkyl, aryl, alkylaryl or arylalkyl esters of adipic diacids, methylglutaric diacids, and ethylsuccinic diacids

(22) Generally, polyamide is a copolymer prepared by a condensation reaction formed by reacting a diamine and a dicarboxylic acid. Specifically, polyamide 6,6 is a copolymer prepared by a condensation reaction formed by reacting a diamine, typically hexamethylenediamine, with a dicarboxylic acid, typically adipic acid.

(23) In one embodiment, the blend of dibasic esters can be derived from one or more by-products in the reaction, synthesis and/or production of adipic acid utilized in the production of polyamide, the composition comprising a blend of dialkyl esters of adipic diacids, glutaric diacids, and succinic diacids (herein referred to sometimes as AGS or the AGS blend).

(24) In one embodiment, the blend of esters is derived from by-products in the reaction, synthesis and/or production of hexamethylenediamine utilized in the production of polyamide, typically polyamide 6,6. The composition comprises a blend of dialkyl esters of adipic diacids, methylglutaric diacids, and ethylsuccinic diacids (herein referred to sometimes as MGA, MGN, MGN blend or MGA blend).

(25) In certain embodiments, the dibasic ester blend comprises:

(26) a diester of formula (IV.a):

(27) ##STR00006##

(28) a diester of formula (IV.b):

(29) ##STR00007##
and

(30) a diester of formula (IV.c):

(31) ##STR00008##

(32) R1 and/or R2 can individually comprise a hydrocarbon having from about 1 to about 8 carbon atoms, typically, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, n-butyl, isoamyl, hexyl, heptyl or octyl. In such embodiments, the blend typically comprises (by weight of the blend) (i) about 15% to about 35% of the diester of formula (IV.a), (ii) about 55% to about 70% of the diester of formula (IV.b), and (iii) about 7% to about 20% of the diester of formula (IV.c), and more typically, (i) about 20% to about 28% of the diester of formula (IV.a), (ii) about 59% to about 67% of the diester of formula (IV.b), and (iii) about 9% to about 17% of the diester of formula (IV.c). The blend is generally characterized by a flash point of 98 C., a vapor pressure at 20 C. of less than about 10 Pa, and a distillation temperature range of about 200-300 C.

(33) In certain other embodiments, the dibasic ester blend comprises:

(34) a diester of the formula (IV.d):

(35) ##STR00009##

(36) a diester of the formula (IV.e):

(37) ##STR00010##
and, optionally,

(38) a diester of the formula (IV.c):

(39) ##STR00011##

(40) R1 and/or R2 can individually comprise a hydrocarbon having from about 1 to about 8 carbon atoms, typically, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, n-butyl, isoamyl, hexyl, heptyl, or octyl. In such embodiments, the blend typically comprises (by weight of the blend) (i) from about 5% to about 30% of the diester of formula (IV.d), (ii) from about 70% to about 95% of the diester of formula (IV.e), and (iii) from about 0% to about 10% of the diester of formula (IV.c). More typically, the blend typically comprises (by weight of the blend): (i) from about 6% to about 12% of the diester of formula (IV.d), (ii) from about 86% to about 92% of the diester of formula (IV.e), and (iii) from about 0.5% to about 4% of the diester of formula (IV.c).

(41) Most typically, the blend comprises (by weight of the blend): (i) about 9% of the diester of formula (IV.d), (ii) about 89% of the diester of formula (IV.e), and (iii) about 1% of the diester of formula (IV.c). The blend is generally characterized by a flash point of 98 C., a vapor pressure at 20 C. of less than about 10 Pa, and a distillation temperature range of about 200-275 C.

(42) In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 70% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 65% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 60% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 55% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 40% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 35% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 30% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide or combination thereof can be present in the liquid agricultural composition at an upper range of 25% by weight of the composition.

(43) In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide can be present in the liquid agricultural composition in an amount between about 7% by weight of the composition to about 55% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide can be present in the composition in an amount between about 8% by weight of the composition to about 50% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide can be present in the liquid agricultural composition in an amount between about 7% by weight of the composition to about 45% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide can be present in the liquid agricultural composition in an amount between about 7% by weight of the composition to about 40% by weight of the composition. In another embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide can be present in the liquid agricultural composition in an amount between about 7% by weight of the composition to about 35% by weight of the composition.

(44) The at least one of alkyl thiophosphoric triamide or dicyandiamide can be present in the composition in an amount between about 0.5% by weight of the composition and about 60% by weight of the composition or, in another embodiment, can be present in the composition in an amount between about 1% by weight of the composition and about 40% by weight of the composition, and, in another embodiment, can be present in the composition in an amount between about 0.5% by weight of the composition and about 20% by weight of the composition. In one particular embodiment, the at least one of alkyl thiophosphoric triamide or dicyandiamide is present in the composition in an amount between about 1% by weight of the composition and about 30% by weight of the composition. The at least one of alkyl thiophosphoric triamide or dicyandiamide means that alkyl thiophosphoric triamide can be solely present, dicyandiamide can be solely present, or a combination of alkyl thiophosphoric triamide and dicyandiamide is present.

(45) Compounds suitable as the amine stabilizer component of the composition and methods of the present invention are alkanolamines. In another embodiment, the amine stabilizer is a monoalkanolamine. In another embodiment, the amine stabilizer is a dialkanolamine. In another embodiment, the amine stabilizer is a trialkanolamine. In yet another embodiment, the amine stabilizer is a monoethanolamine. In a further embodiment, the amine stabilizer is a diethanolamine. In yet a further embodiment, the amine stabilizer is a triethanolamine. In another embodiment, the alkanol group is chosen from methanol, ethanol, propanol, butanol. The amine stabilizer component forms stable compositions at high temperatures with the nitrification and/or urease inhibitor, which in some embodiments means stability at temperatures ranging from 16 C. to 54 C., in other embodiments, 10 C. to 40 C., in other embodiments, 5 C. to 40 C., in other embodiments, 2 C. to 40 C., or in other embodiments, 0 C. to 40 C.

(46) In another embodiment, compounds suitable as the organic solvent are polar aprotic solvents, heterocyclic alcohol solvents, and/or mixtures thereof, that form liquid, or otherwise stable, compositions with the nitrification and/or urease inhibitor at temperatures at or greater than 16 C., in alternative embodiments, greater than 14 C., in other embodiments, greater than 12 C., in other embodiments, greater than 10 C., in further embodiments, greater than 8 C., in other embodiments, greater than 5 C., in other embodiments, greater than 3 C., in other embodiments, greater than 2 C., in other embodiments, greater than 0 C., in other embodiments, greater than 2 C., in other embodiments, greater than 4 C., in other embodiments, greater than 5 C.

(47) In some embodiments, at high temperature ranges or at greater than a specified temperature (as described herein), the liquid fertilizer composition is stable, meaning the urease and/or nitrification inhibitor(s) do not react with the solvent or solvent component under anticipated manufacturing, storage, and use conditions. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 25 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 27 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 29 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 30 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 32 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 34 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 35 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 37 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 40 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 42 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 44 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 45 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 47 C. In one embodiment, the liquid fertilizer compositions are stable at a temperature greater than 50 C.

(48) In one embodiment, at the specified temperature ranges or at greater than a specified temperature (as described herein), the liquid fertilizer composition is stable, meaning the liquid fertilizer composition is or substantially is in one phase, i.e., no visible crystals, no visible precipitation, and/or no visible multiple liquid phases. In another embodiment, the liquid fertilizer composition is stable, meaning the liquid fertilizer composition is or substantially is in one phase and shows little or slight discoloration.

(49) In one embodiment, the liquid fertilizer compositions contains an organophosphate compound according to formula (I.a) (wherein R.sub.1, R.sub.2 and R.sub.3 are as described above).

(50) Suitable polar aprotic organic solvents include, for example, dichloromethane, dimethyl acetamide, dimethyl formamide, dimethyl sulfoxide, ethyl acetate, hexamethylphosphoramide, dimethyl sulfone, sulfolane, 1,3-dimethyl-2-imidazoidinone, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidone, methyl acetate, ethyl lactate, methylpyrrolidone, tetrahydrofuran, propylene carbonate, and dibasic ester solvents.

(51) Suitable dibasic ester solvents include, for example, dialkyl esters of dicarboxylic acids, more typically, the di(C.sub.1-C.sub.12)alkyl esters of saturated linear or branched (C.sub.2-C.sub.8)aliphatic carboxylic acids or a mixture thereof. In one embodiment, the dibasic ester component comprises one or more compounds according to formula (III):
R.sup.1OOC-A-CONR.sup.2R.sup.3(III)
wherein: A is a divalent linear or branched (C.sub.2-C.sub.8)aliphatic group, and R.sup.1, R.sup.2, and R.sup.3 are each independently (C.sub.1-C.sub.12)alkyl, (C.sub.1-C.sub.12)aryl, (C.sub.1-C.sub.12)alkaryl or (C.sub.1-C.sub.12)arylalkyl, and R.sup.2 and R.sup.3 may each optionally be substituted with one or more hydroxyl groups.

(52) In one embodiment, the dibasic ester solvent component of the compositions and methods of the present invention comprises one or more dimethyl esters of saturated linear or branched (C.sub.4-C.sub.6)aliphatic carboxylic acids, such the dimethyl ester of succinic acid, dimethyl ester of ethyl succinic acid, the dimethyl ester of glutaric acid, the dimethyl ester of methyl glutaric acid, and the dimethyl ester of adipic acid, and mixtures thereof. In one embodiment, the dibasic ester component comprises the dimethyl ester of succinic acid, the dimethyl ester of glutaric acid, and optionally, the dimethyl ester of adipic acid, In another embodiment, the dibasic ester component comprises the dimethyl ester of ethyl succinic acid, the dimethyl ester of methyl glutaric acid, and optionally, the dimethyl ester of adipic acid.

(53) In one embodiment, the dibasic ester solvent component of the compositions and methods of the present invention comprises one or more dialkyl esters of saturated linear or branched (C.sub.4-C.sub.6)aliphatic carboxylic acids, such the dialkyl ester of succinic acid, dialkyl ester of ethylsuccinic acid, the dialkyl ester of glutaric acid, the dialkyl ester of methylglutaric acid, and the dialkyl ester of adipic acid, and mixtures thereof. In one embodiment, the dibasic ester component comprises the dialkyl ester of succinic acid, the dialkyl ester of glutaric acid, and optionally, the dimethyl ester of adipic acid, In another embodiment, the dibasic ester component comprises the dialkyl dimethyl ester of ethylsuccinic acid, the dialkyl ester of methylglutaric acid, and optionally, the dialkyl ester of adipic acid. Each alkyl group in the dialkyl group, one embodiment, individually comprise a C.sub.1-C.sub.8 alkyl. In another embodiment, each alkyl group in the dialkyl group, one embodiment, individually comprise a C.sub.1-C.sub.4 alkyl. In another embodiment, each alkyl group in the dialkyl group, one embodiment, individually comprise a C.sub.1-C.sub.6 alkyl.

(54) Suitable amine solvents include primary amines, including monoalkylamines, such as propylamine, secondary amines, including dialkyl amines and diaryl amines, such as dimethylamine and diphenylamine, and tertiary amines, such as diethylene triamine and methyl-5-(dimethylamino)-2-methyl-oxopentanoate.

(55) In one embodiment, the amine solvent component of the compositions and methods of the present invention is selected from aliphatic or aromatic primary, secondary, or tertiary amines may optionally further comprise one or more additional functional groups, such as hydroxyalkyl groups, hydroxyl groups, carbonyl groups, or alkyl ester groups, other than one or more amino groups.

(56) In one embodiment, the organic solvent component of the compositions and methods of the present invention comprises an amino alcohol. Compounds suitable as the amino alcohol solvent component of the compositions and methods of the present invention are those compounds that comprise at least one primary, secondary, or tertiary amino moiety per molecule and at least one hydroxyalkyl moiety per molecule, more typically In one embodiment, the amino alcohol is a linear, branched, or cyclic, saturated or unsaturated hydrocarbon that is substituted on at least one carbon atom with an amino group and on at least one other carbon atom with hydroxyalkyl or hydroxyl group, such as monoethanolamine, ethylaminoethanol, dimethylaminoethanol, isopropylaminoethanol, diethanolamine, triethanolamine, methylaminoethanol, aminopropanol, methylaminopropanol, dimethylaminopropanol, aminobutanol, dimethylaminobutanol, aminobutanediol, trihydroxymethylaminoethane, diethylaminopropanediol, 1-amino-cyclopentane methanol, and aminobenzyl alcohol, or a heterocyclic ring that comprises at least one nitrogen atom as a ring member and/or is substituted on at least one carbon atom with an amino group and that is substituted on at least one other carbon atom with a hydroxyalkyl or hydroxyl group, such as methylaminomethyl-1,3-dioxolane.

(57) Suitable heterocyclic alcohol solvents include, for example, 5- or 6-membered heterocyclic rings that include 1 or 2 oxygen atoms as ring member, that are substituted on at least one carbon atom of the ring with a (C.sub.1-C.sub.6)hydroxyalkyl group, and that may optionally be substituted on one or more carbon atoms of the ring with one or more (C.sub.1-C.sub.4)alkyl groups. It is understood that the term heterocyclic alcohol includes dioxolane compounds. In one embodiment, the heterocyclic alcohol component of the present invention comprises a one or more compounds selected from heterocyclic alcohols according to formulas (II.c), (II.d), (II.e), (II.f), and (II.g):

(58) ##STR00012##

(59) In one embodiment, the organic solvent component comprises one or more dibasic ester compounds according to any of formula (III) or formula (IV), one or more amino alcohols, one or more tertiary amines, one or more heterocyclic alcohols according to formulas (II.a-II.g), or mixtures thereof.

(60) In one embodiment, the organic solvent component of the composition and methods of the present invention comprises dimethyl sulfoxide, dimethyl formamide, the dimethyl ester of succinic acid, dimethyl ester of ethyl succinic acid, the dimethyl ester of glutaric acid, the dimethyl ester of methyl glutaric acid, and the dimethyl ester of adipic acid, diethylene triamine, or monoethanolamine, methyl-5-(dimethylamino)-2-methyl-oxopentanoate, dimethylaminoethanol, triethanol amine, a heterocyclic alcohol according to any of formulas (II.a-II.g), or a mixture thereof.

(61) In one embodiment, the organic solvent component of the composition and methods of the present invention comprises dimethyl sulfoxide, dimethyl formamide, diethylene triamine, monoethanolamine, or a mixture thereof.

(62) In one embodiment, the organic solvent component of the composition and methods of the present invention comprises a mixture of at least one organophosphate solvent according to formula (I.a), wherein R.sub.1, R.sub.2 and R.sub.3 are as described above, and dimethyl sulfoxide.

(63) In one embodiment, a compound utilized as the solvent or as a component in the solvent blend is a compound of general formula (III):
R.sub.3OOC-A-CONR.sub.4R.sub.5(III),

(64) According to one embodiment, the expression compound denotes any compound corresponding to the general formula (III). In other embodiments, the term compound also refers to mixtures of several molecules corresponding to general formula (III). It may therefore be a molecule of formula (III) or a mixture of several molecules of formula (III), wherein both fall under the definition of the term compound when referring to formula (III).

(65) The R.sub.3, R.sub.4 and R.sub.5 groups can be, in some embodiments, identical or, in other embodiment, different. In one embodiment, may be groups chosen from C.sub.1-C.sub.20 alkyl, aryl, alkaryl or arylalkyl groups or the phenyl group. In another embodiment, may be groups chosen from C.sub.1-C.sub.12 alkyl, aryl, alkaryl or arylalkyl groups or the phenyl group. Mention is made especially of Rhodiasolv PolarClean (Manufactured by Solvay USA Inc., Cranbury, N.J.). The R.sub.4 and R.sub.5 groups may optionally be substituted. In one particular embodiment, the groups are substituted with hydroxyl groups.

(66) In one embodiment, R.sub.3 group is chosen from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, isoamyl, n-hexyl, cyclohexyl, 2-ethylbutyl, n-octyl, isooctyl, 2-ethylhexyl, tridecyl groups.

(67) R.sub.4 and R.sub.5 groups, which are identical or different, in one embodiment, may especially be chosen from methyl, ethyl, propyl (n-propyl), isopropyl, n-butyl, isobutyl, n-pentyl, amyl, isoamyl, hexyl, cyclohexyl or hydroxyethyl groups. The R.sub.4 and R.sub.5 groups may also be such that they form, together with the nitrogen atom, a morpholine, piperazine or piperidine group. According to some embodiments, R.sub.4 and R.sub.5 are each methyl, or R.sub.4 and R.sub.5 are each ethyl, or R.sub.4 and R.sub.5 are each hydroxyethyl.

(68) According to one embodiment, if A comprises a linear group of formula CH.sub.2CH.sub.2 and/or of formula CH.sub.2CH.sub.2CH.sub.2CH.sub.2 and/or of formula (CH.sub.2).sub.8 then it is a mixture of A groups. According to one particular embodiment, if A is linear, then it is a mixture of A groups, for example a mixture of two or three CH.sub.2CH.sub.2 (ethylene); CH.sub.2CH.sub.2CH.sub.2 (n-propylene); and CH.sub.2CH.sub.2CH.sub.2CH.sub.2 (n-butylene) groups (or isomers thereof).

(69) According to a first particular embodiment of the invention, the A group is a divalent linear alkyl group chosen from the groups of the following formulae: CH.sub.2CH.sub.2 (ethylene); CH.sub.2CH.sub.2CH.sub.2 (n-propylene); CH.sub.2CH.sub.2CH.sub.2CH.sub.2 (n-butylene), and mixtures thereof.

(70) In one embodiment, the inhibitor composition of the present invention comprises, based on 100 parts by weight (pbw) of the composition:

(71) from about 4 to about 60 pbw, more typically from about 10 to about 55 pbw, and even more typically from about 20 to about 40 pbw dicyandiamide, and

(72) from about 55 to about 96 pbw, more typically from about 58 to about 90 pbw, and even more typically from about 60 to about 80 pbw of the organic solvent.

(73) In one embodiment, the inhibitor composition of the present invention comprises one or more urease inhibitors, such as, for example, NBPT or ammonium thiosulfate.

(74) The nitrogenous fertilizer compound is treated with the inhibitor composition by contacting the nitrogenous fertilizer composition with the inhibitor composition described herein (e.g., nitrification inhibitor or urease inhibitor or a combination of both). The nitrogenous fertilizer composition may be in solid or liquid form.

(75) Suitable nitrogenous fertilizers are those containing a nitrogenous compound such as urea, nitrate salts, ammonium salt, or a mixture thereof, such as ammonium nitrate, ammonium sulfate, ammonium thiosulfate, ammonium polysulfide, ammonium phosphates, ammonium chloride, ammonium bicarbonate, anhydrous ammonia, calcium nitrate, nitrate soda, calcium cyanamide. In one embodiment, the nitrogenous fertilizer comprises ammonium nitrate. Suitable ammonium nitrate-containing fertilizers include, for example, UAN 18, UAN 28, and UAN 30.

(76) In one embodiment, the nitrogenous fertilizer composition is in solid particulate form, and the contacting of the nitrogenous fertilizer composition with the inhibitor composition is conducted by, for example, spraying the composition of the present invention on the particles of solid fertilizer composition.

(77) In one embodiment, the concentrated fertilizer composition of the present invention is a solid nitrification-inhibited fertilizer composition that comprises, based on 100 pbw of the composition:

(78) from about 60 pbw to about 99.999, more typically from about 70 pbw to about 99.999, and even more typically from about 80 pbw to about 99.999 solid particles of one or more nitrogenous fertilizer compounds, and

(79) from about 0.001 to about 40 pbw, more typically from about 0.001 to about 30 pbw, and even more typically from about 0.001 to about 20 pbw, dicyandiamide.

(80) In one embodiment, the solid nitrification-inhibited fertilizer composition of the present invention further comprises one or more urease inhibitors, more typically NBPT.

(81) In one embodiment, the end use fertilizer composition of the present invention is made by combining the inhibitor composition of the present invention with a solid nitrogenous fertilizer to form a solid nitrification-inhibited fertilizer composition and subsequently dissolving the solid nitrification-inhibited fertilizer composition in an aqueous medium, typically water, in a ratio of up to about 500 pbw, more typically from 100 to 500 pbw and even more typically from about 100 to about 300 pbw, of the aqueous medium per 1 pbw of the solid nitrification-inhibited fertilizer composition.

(82) In one embodiment, the fertilizer compound is in liquid form and the contacting of the fertilizer composition with the inhibitor composition is conducted by mixing the inhibitor composition with the liquid fertilizer composition.

(83) In one embodiment, the concentrated fertilizer composition of the present invention is a concentrated liquid nitrification-inhibited fertilizer composition that comprises, based on 100 pbw of the composition:

(84) from about 20 to about 99.989 pbw, more typically from about 30 to about 99.985 pbw, and even more typically from about 40 to about 99.98 pbw of one or more nitrogenous fertilizer compounds,

(85) from about 0.001 to 40 pbw, more typically from about 0.005 to 30 pbw, and even more typically from about 0.01 to 20 pbw NBPT (or NBPT in combination with DCD), and

(86) from about 0.01 to 60 pbw, more typically from about 0.01 to about 40 pbw, and even more typically from about 0.01 to about 30 pbw of the organic solvent or solvent mixture, as described herein.

(87) In one embodiment, the concentrated liquid nitrification-inhibited fertilizer composition of the present invention further comprises one or more urease inhibitors, more typically NBPT.

(88) In one embodiment, the end use fertilizer composition of the present invention is made by combining the inhibitor composition of the present invention with a concentrated nitrogenous fertilizer to form a concentrated liquid nitrification-inhibited fertilizer composition and subsequently diluting the concentrated liquid nitrification-inhibited fertilizer composition with an aqueous medium, typically water in a ratio of up to about 500 pbw, more typically from about 10 to about 500 pbw and even more typically from about 100 to about 300 pbw, of the aqueous medium per 1 pbw concentrated liquid nitrogenous fertilizer composition.

(89) In one embodiment, the end use fertilizer composition of the present invention is made by combining the inhibitor composition of the present invention, a solid or concentrated liquid nitrogenous fertilizer, and an aqueous medium.

(90) In one embodiment, the end use fertilizer composition of the present invention is an aqueous liquid composition that comprises water, one or more nitrogenous fertilizer compounds, and dicyandiamide, typically in an amount of from 210.sup.6 pbw to about 4 pbw dicyandiamide per 100 pbw of the end use fertilizer composition.

(91) In one embodiment, the end use fertilizer composition of the present invention comprises water and based on 100 parts by weight of the composition:

(92) from about 0.04 to about 10 pbw, more typically from about 0.06 to about 10 pbw, and even more typically from about 0.08 pbw to about 10 pbw to of one or more nitrogenous fertilizer compounds,

(93) from about 210.sup.6 to about 4 pbw, more typically from about 110.sup.5 to about 3 pbw, and even more typically from about 210.sup.4 to about 2 pbw dicyandiamide, and

(94) from about 210.sup.4 to about 6 pbw, more typically from about 210.sup.4 to about 4 pbw, and even more typically from about 210.sup.4 to about 3 pbw of the organic solvent.

(95) In one embodiment, the end use fertilizer composition of the present invention comprises one or more urease inhibitors, more typically NBPT, alone or in combination with the nitrification inhibitor.

(96) In one embodiment, the end use fertilizer composition of the present invention comprises from about 0.001 to about 5 pbw, more typically from about 0.01 to about 2 pbw dicyandiamide per 100 pbw of the one or more nitrogenous fertilizer compounds.

(97) In one embodiment, the end use fertilizer composition is applied to target plants or to an environment for the target plants, i.e., to ground on or within which the target plants are growing or to be grown, at a rate of from about 0.01 pounds to about 5 pounds of the fertilizer composition, more typically from about 0.05 pounds to about 2 pounds of the fertilizer composition, per 100 square feet of ground.

(98) In one embodiment, the end use fertilizer composition is applied to target plants or to an environment for the target plants at a rate effective to provide a dosage of nitrogenous fertilizer compound of from about 0.01 pounds to about 5 pounds of fertilizer compound, more typically from about 0.05 pounds to 2 pounds of fertilizer compound, per 100 square feet of ground.

(99) In one embodiment, the end use fertilizer composition is applied to target plants or to an environment for the target plants at a rate effective to provide a dosage of dicyandiamide of from about 0.01 pounds to 5 pounds of dicyandiamide, more typically from about 0.05 pounds to 2 pounds of dicyandiamide, per 1000 square feet of ground.

(100) The composition of the present invention provides improved ease of handling of dicyandiamide, improved solubility characteristics, low toxicity of the organic solvents; good storage characteristics, and excellent miscibility with aqueous compositions, such as aqueous nitrogenous fertilizer formulations.

(101) In one embodiment the composition comprises, by weight of composition, greater than 50 wt % of DCD and/or NBPT, the remainder being solvent or a mixture of solvents with the amine stabilizer. By way of example, in one embodiment, the fertilizer composition comprises, by weight of composition, 50 wt % of DCD and 50 wt % of a solvent blend of DMSO and at least one amine stabilizer as described above.

(102) In one embodiment the composition comprises, by weight of composition, greater than 50 wt % of NBPT, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 51 wt %, 52 wt %, 53 wt %, 54 wt % of NBPT, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 55 wt %, 56 wt %, 57 wt %, 58 wt %, 59 wt % of NBPT, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 60 wt % of NBPT, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 65 wt % of NBPT, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 70 wt % of NBPT, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 75 wt % of NBPT, the remainder being solvent or a mixture of solvents with the amine stabilizer.

(103) In one embodiment the composition comprises, by weight of composition, greater than 50 wt % of NBPT in combination with DCD, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 51 wt %, 52 wt %, 53 wt %, 54 wt % of NBPT in combination with DCD, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 55 wt %, 56 wt %, 57 wt %, 58 wt %, 59 wt % of NBPT in combination with DCD, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 60 wt % of NBPT in combination with DCD, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 65 wt % of NBPT in combination with DCD, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 70 wt % of NBPT in combination with DCD, the remainder being solvent or a mixture of solvents with the amine stabilizer. In one embodiment the composition comprises, by weight of composition, greater than 75 wt % of NBPT in combination with DCD, the remainder being solvent or a mixture of solvents with the amine stabilizer.

(104) In one embodiment the composition comprises, by weight of composition, greater than 30 wt % of DCD and/or NBPT, the remainder being solvent or a mixture of solvents with the amine stabilizer. By way of example, in one embodiment, the fertilizer composition comprises, by weight of composition, 30 wt % of DCD and 70 wt % of a solvent blend of: (i) at least one dioxolane compound of formula (II.b):

(105) ##STR00013##

(106) wherein R.sub.6 and R.sub.7 individually comprises a hydrogen, an alkyl group, an alkenyl group, or a phenyl group, wherein n is an integer of from 1 to 10.

(107) In one embodiment the composition comprises, by weight of composition, greater than 40 pbw of NBPT (or NBPT in combination with DCD), the remainder being solvent or a mixture of solvents.

(108) In one embodiment the composition comprises, by weight of composition, greater than 35 pbw of NBPT (or NBPT in combination with DCD), the remainder being solvent or a mixture of solvents.

(109) In one embodiment the composition comprises, by weight of composition, greater than 45 pbw of DCD and/or NBPT, the remainder being solvent or a mixture of solvents. By way of example, in one embodiment, the fertilizer composition comprises, by weight of composition, 45 wt % of DCD and 55 wt % of a solvent blend of:

(110) (i) at least one dioxolane compound of formula (II.b) or formula (II.a), wherein R.sub.6 and R.sub.7 are as described above; and

(111) (ii) at least one amine stabilizer as described herein.

(112) In one embodiment the composition comprises, by weight of composition, greater than 55 pbw of DCD and/or NBPT, the remainder being solvent or a mixture of solvents. By way of example, in one embodiment, the fertilizer composition comprises, by weight of composition, 55 wt % of DCD and 45 wt % of a solvent blend of:

(113) (i) at least one dioxolane compound of formula (II.b) or formula (II.a), wherein R.sub.6 and R.sub.7 are as described above; and

(114) (ii) at least one amine stabilizer as described herein.

EXPERIMENTS

(115) Referring to FIG. 1, Several amines or amides were tested to check if they can stabilize NBPT degradation at high temperatures (at greater than 45 C.) in NBPT/DMSO formulation. Each sample was prepared with 2 wt % of amine stabilizer added. From visual observation, samples prepared with monoethanolamine showed better physical stability (less dark appearance), which is believed to be as a result of less formation of dimethyl sulfide (degradation product from solvent).

(116) Referring to FIG. 2, the photograph shows the results from 10 weeks storage of 2% monoethanolamine in 1:1 NBPT:DMSO at two different temperatures, 45 C. and Room Temperature, RT (20 C.).

(117) Referring to FIG. 3, it shows a chart of the degradation product, i.e., dimethyl sulfide (DMS) in parts per million (ppm), measured at varying high temperatures for a period of weeks. The results indicate the liquid fertilizer composition with the amine stabilizer exhibited higher stability over time versus a liquid fertilizer composition without the stabilizer.