IMPROVED UREA AMMONIUM SULPHATE-BASED COMPOSITION AND METHOD FOR THE MANUFACTURE THEREOF

Abstract

The invention relates to a homogeneous, solid, particulate, urea ammonium sulphate-based composition comprising urea ammonium sulphate and a urease inhibitor of the type phosphoric triamide, wherein the urea ammonium sulphate-based composition is further characterized in that one or more of the following measures applies: a) it comprises 5 weight % or less, relative to the total weight of the composition, of one or more alkaline or alkaline-forming inorganic or organic compounds that is able to interact with ammonium sulphate; b) the urease inhibitor of the type phosphoric triamide is in a solid particulate form; c) an anticaking and/or moisture repellent coating is applied onto the urea ammonium sulphate particulate material. The composition according to the invention has improved properties for reducing ammonia loss by urease activity in the soil and is in particular suitable as a fertilizer. The invention further relates to a method for the manufacture of a homogeneous, solid, particulate urea ammonium sulphate-based composition comprising urea, ammonium sulphate and a urease inhibitor of the type phosphoric triamide, in particular N-(n-butyl) thiophosphoric triamide (nBTPT), as well as to a composition of kit of parts comprising: a) one or more alkaline or alkaline-forming inorganic compounds that is able to interact with ammonium sulphate; b) the urease inhibitor of the type phosphoric triamide in solid particulate or liquid form, preferably wherein the urease inhibitor is N-(n-butyl) thiophosphoric triamide (nBTPT); c) optionally, one or more anticaking and/or moisture repellent compounds.

Claims

1-24. (canceled)

25. A homogeneous, solid, particulate, urea ammonium sulphate-based composition comprising urea ammonium sulphate and a urease inhibitor of the type phosphoric triamide, wherein the urea ammonium sulphate-based composition is further characterized in that one or more of the following measures applies: a) it comprises from 0.0001 to 5 weight %, relative to the total weight of the composition, of one or more alkaline or alkaline-forming inorganic or organic compounds that is able to interact with ammonium sulphate, selected from the group of metal oxides, such as calcium oxide, magnesium oxide, zinc oxide, sodium oxide, aluminium oxide, barium oxide and copper oxide; carbonates, such as calcium carbonate, sodium carbonate, ammonium carbonate, barium carbonate; hydroxides, such as aluminium hydroxide, ammonium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, iron hydroxide, barium hydroxide and tetraalkyl/aryl ammonium hydroxides; and acetates, such as sodium acetate, ammonium acetate, magnesium acetate, zinc acetate and barium acetate, and any mixture thereof; or, selected from the group of organic bases, such as ammonia; amines, such as triethylamine, ethanolamine and triethanolamine; amides, such as sodium amide and magnesium diamide; adenines; amidines; guanidines; anilines; carbamates; thiazoles; triazoles; pyridines; imidazoles; benzimidazoles; histidines; phosphazenes, and any mixture thereof; b) the urease inhibitor of the type phosphoric triamide is in a solid particulate form; c) an anticaking and/or moisture repellent coating is applied onto the urea ammonium sulphate particulate material.

26. The urea ammonium sulphate-based composition according to claim 25, characterized in that: a) it comprises from 0.0001 to 5 weight %, relative to the total weight of the composition, of one or more alkaline or alkaline-forming inorganic or organic compounds that is able to interact with ammonium sulphate; and b) the urease inhibitor of the type phosphoric triamide is in a solid particulate form.

27. The urea ammonium sulphate-based composition according to claim 25, characterized in that: a) it comprises from 0.0001 to 5 weight %, relative to the total weight of the composition, of one or more alkaline or alkaline-forming inorganic or organic compounds that is able to interact with ammonium sulphate; and c) a moisture repellent coating is applied onto the urea ammonium sulphate particulate material.

28. The urea ammonium sulphate-based composition according to claim 25, characterized in that: b) the urease inhibitor of the type phosphoric triamide is in a solid particulate form; and c) a moisture repellent coating is applied onto the urea ammonium sulphate particulate material.

29. The urea ammonium sulphate-based composition according to claim 25, characterized in that: a) it comprises from 0.0001 to 5 weight %, relative to the total weight of the composition, of one or more alkaline or alkaline-forming inorganic or organic compounds that is able to interact with ammonium sulphate; and b) the urease inhibitor of the type phosphoric triamide is in a solid particulate form; and c) a moisture repellent coating is applied onto the urea ammonium sulphate particulate material.

30. The urea ammonium sulphate-based composition according to claim 25, characterized in that the urease inhibitor of the type phosphoric triamide is a compound of formula: ##STR00003## wherein: X is oxygen or sulphur; R.sub.1 is alkyl, cycloalkenyl, aralkyl, aryl, alkenyl, alkynyl, or cycloalkyl; R.sub.2 is hydrogen, alkyl, cycloalkenyl, aralkyl, aryl, alkenyl, alkynyl, or cycloalkyl, or R.sub.1 and R.sub.2 together may form an alkylene or alkenylene chain which may optionally include one or more heteroatoms of divalent oxygen, nitrogen or sulphur completing a 4, 5, 6, 7, or 8 membered ring system; and R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are individually hydrogen or alkyl having 1 to 6 carbon atoms.

31. The urea ammonium sulphate-based composition according to claim 25, wherein the urease inhibitor is N-(n-butyl) thiophosphoric triamide (nBTPT).

32. The urea ammonium sulphate-based composition according to claim 25, wherein the urease inhibitor, in particular N-(n-butyl) thiophosphoric triamide (nBTPT) is present at a level of 0.0001-1% weight %, preferable 0.02-0.2% weight %, most preferably 0.04-0.06 weight %.

33. The urea ammonium sulphate-based composition according to claim 25, wherein the alkaline or alkaline-forming inorganic or organic compound is selected from the group of metal oxides, carbonates, hydroxides, acetates, and organic bases, and mixtures thereof.

34. The urea ammonium sulphate-based composition according to claim 33, wherein the alkaline or alkaline-forming compound is selected from the group of calcium oxide, zinc oxide, magnesium oxide, calcium carbonate, and mixtures thereof.

35. The urea ammonium sulphate-based composition according to claim 33, wherein the alkaline or alkaline-forming compound is present in the composition at a level of 0.02-1 weight %, most preferably 0.05-1 weight %.

36. The urea ammonium sulphate-based composition according to claim 35, wherein the weight ratio of urease inhibitor of the type phosphoric triamide to one or more alkaline or alkaline-forming inorganic compounds that is able to interact with ammonium sulphate in the compositions according to the invention ranges from 1:20 to 1:1, preferably from 1:15 to 1:1, more preferably from 1:10 to 1:1.

37. The urea ammonium sulphate-based composition according to claim 25, wherein the urease inhibitor is in solid particulate form.

38. The urea ammonium sulphate-based composition according to claim 25, wherein the anticaking and/or moisture repellent coating comprising at least a wax, oil and a resin which is oil-soluble and miscible with wax.

39. The urea ammonium sulphate-based composition according to claim 25, wherein the urea ammonium sulphate-based composition is bagged without the presence of a head space.

40. The urea ammonium sulphate-based composition according to claim 25, wherein the urea ammonium sulphate-based composition comprises 50-100 weight % of UAS.

41. The urea ammonium sulphate-based composition according to claim 40, wherein the UAS is a co-granulated material, preferably obtained from melt-mixing molten urea and solid particulate ammonium sulphate, from compacting finely divided solid urea and ammonium sulphate powders, or from a chemical process for the production of urea from carbon dioxide and ammonia, wherein ammonia is neutralized to form ammonium sulphate (AS) in the urea melt or solution to produce UAS.

42. The urea ammonium sulphate-based composition according to claim 41, wherein the composition may contain from about 0.1 to 60 weight % of ammonium sulphate.

43. Use of the homogeneous, solid, particulate urea ammonium sulphate-based composition as claimed in claim 25 as a fertilizer.

44. Use of the homogeneous, solid, particulate urea ammonium sulphate-based composition as claimed in claim 25 for supporting the growth of agricultural products on a sulphur-deficient soil.

45. Use of the homogeneous, solid, particulate urea ammonium sulphate-based composition as claimed in claim 25 as an animal feed.

46. A method for the manufacture of a homogeneous, solid, particulate, urea ammonium sulphate-based composition according to claim 25, the method comprising the steps of: 1) providing a urea ammonium sulphate material; 2) adding from 0.0001 to 5 weight %, relative to the total weight of the composition, of one or more alkaline or alkaline-forming inorganic or organic compounds that is able to interact with ammonium sulphate, selected from the group of metal oxides, such as calcium oxide, magnesium oxide, zinc oxide, sodium oxide, aluminium oxide, barium oxide and copper oxide; carbonates, such as calcium carbonate, sodium carbonate, ammonium carbonate, barium carbonate; hydroxides, such as aluminium hydroxide, ammonium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, iron hydroxide, barium hydroxide and tetraalkyl/aryl ammonium hydroxides; and acetates, such as sodium acetate, ammonium acetate, magnesium acetate, zinc acetate and barium acetate, and any mixture thereof; or, selected from the group of organic bases, such as ammonia; amines, such as triethylamine, ethanolamine and triethanolamine; amides, such as sodium amide and magnesium diamide; adenines; amidines; guanidines; anilines; carbamates; thiazoles; triazoles; pyridines; imidazoles; benzimidazoles; histidines; phosphazenes, and any mixture thereof; 3) adding a urease inhibitor in solid particulate or liquid form, preferably wherein the urease inhibitor is N-(n-butyl) thiophosphoric triamide (nBTPT); and 4) optionally, applying a coating that is able to increase at least the water repellence and/or anticaking properties of urea ammonium sulphate, preferably wherein said coating is as disclosed in EP 0768993 A1; wherein the steps 2), 3) and 4) can be interchanged or wherein steps 2), 3) and 4) can be performed simultaneously.

47. A kit of parts, comprising a) one or more alkaline or alkaline-forming inorganic compounds that is able to interact with ammonium sulphate, preferably wherein the alkaline or alkaline-forming compound is selected from the group of metal oxides, carbonates, hydroxides, acetates, and mixtures thereof; b) the urease inhibitor of the type phosphoric triamide in solid particulate or liquid form, preferably wherein the urease inhibitor is N-(n-butyl) thiophosphoric triamide (nBTPT); c) optionally, one or more anticaking and/or moisture repellent compounds.

48. Method for improving the stability of a urease inhibitor of the type phosphoric triamide, in particular N-(n-butyl) thiophosphoric triamide, (nBTPT) in an urea ammonium sulphate-based composition comprising urea ammonium sulphate and said urease inhibitor, by one or more of the following measures: a) addition to the composition of from 0.0001 to 5 weight %, relative to the total weight of the composition, of one or more alkaline or alkaline-forming inorganic or organic compounds that is able to interact with ammonium sulphate, selected from the group of metal oxides, such as calcium oxide, magnesium oxide, zinc oxide, sodium oxide, aluminium oxide, barium oxide and copper oxide; carbonates, such as calcium carbonate, sodium carbonate, ammonium carbonate, barium carbonate; hydroxides, such as aluminium hydroxide, ammonium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, iron hydroxide, barium hydroxide and tetraalkyl/aryl ammonium hydroxides; and acetates, such as sodium acetate, ammonium acetate, magnesium acetate, zinc acetate and barium acetate, and any mixture thereof; or, selected from the group of organic bases, such as ammonia; amines, such as triethylamine, ethanolamine and triethanolamine; amides, such as sodium amide and magnesium diamide; adenines; amidines; guanidines; anilines; carbamates; thiazoles; triazoles; pyridines; imidazoles; benzimidazoles; histidines; phosphazenes, and any mixture thereof; or b) selection of a urease inhibitor of the type phosphoric triamide which is in a solid particulate form; or c) application of an anticaking and/or moisture repellent coating onto the particulate urea ammonium sulphate material.

Description

EXAMPLES

Description of Figures

[0076] FIG. 1. Stability of different liquid nBTPT-formulations applied on particulate urea versus applied on particulate UAS-% recovery of nBTPT after 28 days of storage under bagged storage conditions at room temperature (20-25 C.). [A=Agrotain Ultra (KOCH), B=N Yield (Eco Agro), C=Rhodia Ag-Rho N Protect (Solvay)].

[0077] FIG. 2. Stability of Agrotain Ultra (KOCH), applied on particulate urea versus applied on particulate UAS after 5 days of storage open to air at 30 C./60% relative humidity.

[0078] FIG. 3. Stability of nBTPT on particulate UAS: effect of the addition of different alkaline compounds% recovery of nBTPT after 12 days of open to air storage at 30 C. in an oven. [0079] A=UAS+500 ppm nBTPT powder; [0080] B=UAS+500 ppm nBTPT powder+2350 ppm rapeseed oil; [0081] C=UAS+500 ppm nBTPT powder+2350 ppm rapeseed oil+2650 ppm CaO; [0082] D=UAS+500 ppm nBTPT powder+2350 ppm rapeseed oil+2650 ppm CaCO.sub.3; [0083] E=UAS+500 ppm nBTPT powder+2350 ppm rapeseed oil+150 ppm ethanolamine; [0084] F=UAS+500 ppm nBTPT powder+2350 ppm rapeseed oil+2650 ppm ZnO.

[0085] FIG. 4. Stability of nBTPT on particulate UAS: effect of the addition of CaO in different concentrations% recovery of nBTPT after 8 days of open to air storage at nissenhut (day/night cycle 16-42 C./27-77% relative humidity). [0086] A=UAS+500 ppm nBTPT powder; [0087] B=UAS+500 ppm nBTPT powder+500 ppm CaO; [0088] C=UAS+500 ppm nBTPT powder+1000 ppm CaO; [0089] D=UAS+500 ppm nBTPT powder+2650 ppm CaO.

[0090] FIG. 5. Stability of different liquid nBTPT-formulations applied on particulate UAS versus nBTPT in solid form on particulate UAS% recovery of nBTPT after 28 days of storage under bagged storage conditions at room temperature (20-25 C.). [0091] A=500 ppm nBTPT as Agrotain Ultra (KOCH)liquid, [0092] B=500 ppm nBTPT as N Yield (Eco Agro)liquid, [0093] C=500 ppm nBTPT as Rhodia Ag-Rho N Protect (Solvay)liquid, [0094] D=500 ppm solid nBTPT (Sunfit Chemical Co.) FIG. 6. Stability of solid nBTPT (500 ppm) on particulate UAS: effect of the addition of different coatings% recovery of nBTPT after 28 days of storage in closed plastic containers with head space at 20 C./80% relative humidity. [0095] A=no coating; [0096] B=Novoflow 1029 coating; [0097] C=NH coating; [0098] D=Paraffin coating; [0099] E=VHO coating.

[0100] FIG. 7. Stability of solid nBTPT (500 ppm) on particulate UAS: bagged versus open to air storage% recovery of nBTPT after 28 days of storage at room temperature (20-25 C.).

[0101] FIG. 8. Stability of nBTPT (500 ppm) on particulate UAS% recovery of nBTPT after 16 days of storage in bags at nissenhut (day/night cycle 16-42 C./27-77% relative humidity). [0102] A=UAS+500 ppm nBTPT as Agrotain Ultra; [0103] B=UAS+500 ppm nBTPT as Agrotain Ultra+2650 ppm CaO; [0104] C=UAS+500 ppm nBTPT powder; [0105] D=UAS+500 ppm nBTPT powder+2650 ppm CaO.

[0106] FIG. 9. Stability of nBTPT on particulate UAS: % recovery of nBTPT after 16 days of storage in nissenhut (day/night cycle 16-42 C./27-77% relative humidity). [0107] A=UAS+500 ppm nBTPT powder; [0108] B=UAS+500 ppm nBTPT powder+2650 ppm CaO

[0109] FIG. 10. Stability of nBTPT on particulate UAS: % recovery of nBTPT after 7 days of storage in closed plastic containers with head space at 20 C./80% relative humidity. [0110] A=uncoated UAS+500 ppm nBTPT as Agrotain Ultra; [0111] B=uncoated UAS+500 ppm nBTPT powder; [0112] C=UAS coated with 4000 ppm NH-coating+500 ppm nBTPT as Agrotain Ultra; [0113] D=UAS coated with 4000 ppm NH-coating+500 ppm nBTPT powder.

[0114] FIG. 11. Stability of nBTPT on particulate UAS: % recovery of nBTPT after 28 days of storage at room temperature (20-25 C.). [0115] A=UAS+500 ppm nBTPT as Agrotain Ultra; [0116] B=UAS+500 ppm nBTPT powder;

[0117] FIG. 12. Stability of nBTPT on particulate UAS% recovery of nBTPT after 16 days of storage in nissenhut (day/night cycle 16-42 C./27-77% relative humidity). [0118] A=uncoated UAS+500 ppm nBTPT as Agrotain Ultra; [0119] B=UAS coated with 900 ppm NH-coating+500 ppm nBTPT as Agrotain Ultra; [0120] C=UAS coated with 900 ppm NH-coating+500 ppm nBTPT powder; [0121] D=UAS coated with 900 ppm NH-coating+500 ppm nBTPT as Agrotain Ultra+2650 ppm CaO; [0122] E=UAS coated with 900 ppm NH-coating+500 ppm nBTPT powder+2650 ppm CaO.

[0123] FIG. 13. Cumulated volatile ammonia losses (mg N/pot) on Rheinland soil (pH 6.5) and Palencia soil (pH 7.5). Experiments were done in three replicate (error bars). [0124] A=urea; [0125] B=UAS; [0126] C=UAS+430 ppm nBTPT powder; [0127] D=UAS+2350 ppm rapeseed oil+420 ppm nBTPT powder+2650 ppm CaO; [0128] E=UAS+2350 ppm NH-coating+420 ppm nBTPT powder+2650 ppm CaO; [0129] F=UAS+2350 ppm rapeseed oil+350 ppm nBTPT powder+ZnO (1% Zn).

EXPERIMENTAL SECTION

1. Volatilization Measurements

[0130] Erlenmeyer flasks were filled with 300 g air-dried, arable topsoil, irrigated to a desired % of its WHC (Water Holding Capacity), incubated for 6 days prior to the application of the fertilizers. Fertilizers (2.5-3.15 mm granule size) at a concentration of 100 mg N/flask were applied over the soil surface. Boric acid traps were installed to catch volatile ammonia from the air above the topsoil, and the Erlenmeyer flasks were installed in a Phytotron chamber at 25 C. at windy but not dry conditions.

Measurements:

[0131] Titration of boric acid traps 3, 7, 10, and 14 days after fertilizer application; [0132] Calculation of cumulative N loss, and N loss reduction in comparison to urea; [0133] Soil pH at the beginning of the trial; [0134] mineral N (NH.sub.4 and NO.sub.3) and total soluble N at the end of trial; [0135] Urea-N calculated as difference between N total and N mineral.
2. nBTPT Experiments

[0136] For lab scale experiments, 1.2 kg of solid fertilizer material was added to a lab scale drum. In a next step, the nBTPT material was slowly added. A residence time of 10 minutes was applied and the rotating speed of the drum was consequently the same in each experiment. In case a moisture repellent coating was added, a nebulizer was used and depending on the order of addition, the moisture repellent coating was added before or after addition of the nBTPT material. Before use, the moisture repellent coating was preheated to 80 C. Larger scale experiments with amounts up to 40 kg of fertilizer material were performed in a concrete mixer.

[0137] The samples were stored under several conditions, dependent on the type of samples: [0138] 20 C. closed plastic container with head space (Climate chamber, 80% relative humidity) [0139] Bagged at room temperature (20-25 C.) or in nissenhut [0140] Open to air in nissenhut [0141] Cylinder test in nissenhut [0142] Open pile in nissenhut

[0143] For some samples, an accelerated stability test was done storing these samples at elevated temperatures: [0144] Oven of 30 C. closed plastic container [0145] Oven of 30 C. open to air [0146] 30 C./60% RH open to air [0147] 70 C. closed plastic container

[0148] Typically, a day/night cycle is generated in the nissenhut, with temperature fluctuations between 0 to 42 C. and fluctuations of relative humidity between 20 and 90%, which can be compared with real life storage in silos.

3. HPLC Analysis of nBTPT-Content

[0149] HPLC analysis of nBTPT is done as described in the procedure CEN 15688-2007.

4. Products

[0150] Urea was obtained from Yara as granules YaraVera Urea 46-0-0 (product code PA38M2).

[0151] UAS was obtained from Yara as granules YaraVera Amidas 40-0-0 (product code PA421X). Solid N-(n-butyl)thiophosphoric triamide was obtained from Sunfit Chemical Co. (China) (CAS-Nr. 94317-64-3), as a white crystalline solid with a melting point of 58-60 C.

[0152] Coating: Moisture repellent (MR) coating was made according to EP 0768993 A1 (Norsk Hydro ASA) by mixing about 28 weight % of wax, about 68 weight % of oil and about 4 weight % of a resin, applied in an amount of about 0.1-0.5% weight % to the fertilizer. It will be referred herein as NH coating.

Example 1

[0153] Example 1 defines the problem. FIG. 1 shows the stability of different commercially available liquid nBTPT-formulations, applied on urea, versus applied on UAS. The % recovery of nBTPT after 28 days of storage under bagged storage conditions at room temperature (20-25 C.) is shown. FIG. 1 shows clearly that, in contrast to urea, when liquid nBTPT formulations are applied on UAS, nBTPT degrades very fast and the nBTPT level drops to 0 weight % only in a few days. FIG. 2 confirms the previous observations for storage open to air and shows the stability of Agrotain Ultra (KOCH), applied on urea, versus applied on UAS. After 5 days of storage open to air at 30 C./60% relative humidity, no nBTPT could be measured on UAS. In contrast, on urea, still 90% of the nBTPT is present.

Example 2

[0154] This example shows the beneficial effect of the addition of an alkaline or alkaline-forming inorganic or organic compound on UAS on the stability of nBTPT in the presence of UAS.

[0155] FIG. 3 shows the stability of nBTPT, coated on UAS without or with the addition of different alkaline inorganic and organic compounds. The recovery of nBTPT after 12 days of open to air storage at 30 C. in an oven is shown.

[0156] FIG. 3 clearly shows the stabilizing effect on nBTPT on UAS by the addition of calcium oxide (solid), calcium carbonate (solid), ethanolamine (liquid) and zinc oxide (solid), where the best effect is obtained for zinc oxide.

[0157] Furthermore, FIG. 4 shows the stability of nBTPT on UAS with the addition of calcium oxide in different concentrations. The recovery of nBTPT after 8 days of open to air storage at nissenhut (day/night cycle 16-42 C./27-77% relative humidity) is presented. The figure clearly shows that the addition of 500-2350 ppm calcium oxide to a composition comprising UAS and nBTPT has a large stabilizing effect on nBTPT on UAS, with a bigger stabilizing effect with increasing concentration of calcium oxide. Although already a large effect is obtained with 500 ppm, further improved stability will be obtained with higher concentrations, the amount to be determined by the skilled person, depending on the type of stabilizer, type of application, type of UAS, etc.

Example 3

[0158] This example shows the beneficial effect of the addition of nBTPT in solid particulate form to UAS on the stability of nBTPT on UAS, in comparison to the addition of nBTPT in liquid form to UAS.

[0159] FIG. 5 shows the stability of different liquid commercially available nBTPT-formulations applied on UAS versus nBTPT in solid particulate form on UAS. The recovery of nBTPT after 28 days of storage under bagged storage conditions at room temperature (20-25 C.) is presented. The results clearly show that the addition of nBTPT in solid particulate form to UAS increases the stability of nBTPT on UAS to a high extent (about 80%) in comparison with the addition of nBTPT in liquid form to UAS.

Example 4

[0160] This example shows the beneficial effect of the addition of a moisture repellent coating on UAS on the stability of nBTPT on UAS.

[0161] FIG. 6 shows the stability of solid nBTPT on UAS with or without the addition of different moisture repellent coatings. The recovery of nBTPT after 28 days of storage in closed plastic containers with head space at 20 C./80% relative humidity is presented. The graph clearly shows the big stabilizing effect of the addition of all the applied moisture repellent coatings on nBTPT on UAS. [0162] No coating: 0% recovery of nBTPT [0163] With coating: 23-41% recovery of nBTPT

Example 5

[0164] This example shows the beneficial effect of the storage in bags without head space versus storage open to air on the stability of nBTPT on UAS.

[0165] FIG. 7 shows the stability of solid nBTPT on UAS when stored in bags versus open to air storage. The recovery of nBTPT after 28 days of storage at room temperature (20-25 C.) is presented. The graph shows clearly the beneficial effect of bagged storage of the material on the stability of nBTPT on UAS in contrast when storage was done open to air.

Example 6

[0166] This example shows the beneficial effect of the combinations of all measures a), b) and c) on the stability of nBTPT on UAS.

[0167] FIG. 8 shows the stability of nBTPT on UAS with or without the addition of alkaline inorganic compound calcium oxide and with or without the application of nBTPT in solid particulate form. The recovery of nBTPT after 16 days of storage in bags at nissenhut (day/night cycle 16-42 C./27-77% relative humidity) is presented. The graph shows clearly the beneficial effect on the stability of nBTPT (liquid and solid) on UAS of [0168] The addition of an alkaline or alkaline-forming inorganic or organic compound (A versus B, C versus D); and [0169] The addition of the urease inhibitor of the type phosphoric triamide is in a solid particulate form (A versus C, B versus D).

[0170] FIG. 9 shows the stability of nBTPT on UAS with or without the addition of alkaline inorganic compound calcium oxide and with or without storage in bags without head space.

[0171] The recovery of nBTPT after 16 days of storage in nissenhut (day/night cycle 16-42 C./27-77% relative humidity) is presented.

[0172] The graph shows clearly the beneficial effect on the stability of nBTPT on UAS of [0173] The addition of an alkaline or alkaline-forming inorganic or organic compound (A versus B); and [0174] Storage of the material under bagged storage conditions without the presence of a head space.

[0175] FIG. 10 shows the stability of nBTPT on UAS with or without the addition of a moisture repellent coating and with or without the application of nBTPT in solid particulate form. The recovery of nBTPT after 7 days of storage in closed plastic containers with head space at 20 C./80% relative humidity is presented.

[0176] The graph shows clearly the beneficial effect on the stability of nBTPT on UAS of [0177] The addition a moisture repellent coating; and [0178] The addition of the urease inhibitor of the type phosphoric triamide is in a solid particulate form.

[0179] FIG. 11 shows the stability of nBTPT on UAS with or without storage in bags without head space and with or without the application of nBTPT in solid particulate form.

[0180] The recovery of nBTPT after 28 days of storage at room temperature (20-25 C.) is presented.

[0181] The graph shows clearly the beneficial effect on the stability of nBTPT on UAS of [0182] The addition of the urease inhibitor of the type phosphoric triamide is in a solid particulate form; and [0183] Storage of the material under bagged storage conditions without the presence of a head space.

[0184] FIG. 12 shows the stability of nBTPT on UAS with or without the addition of alkaline inorganic compound calcium oxide, and with or without the application of nBTPT in solid particulate form, and with or without the addition of a moisture repellent coating, and with or without storage in bags without head space. The recovery of nBTPT after 16 days of storage in nissenhut (day/night cycle 16-42 C./27-77% relative humidity) is presented.

[0185] The graph shows clearly the beneficial effect on the stability of nBTPT on UAS of [0186] The addition an alkaline or alkaline-forming inorganic or organic compound; and [0187] The addition of the urease inhibitor of the type phosphoric triamide is in a solid particulate form; and [0188] The addition of a moisture repellent coating; and [0189] Storage of the material under bagged storage conditions without the presence of a head space.

[0190] In particular, a homogeneous, solid, particulate, urea ammonium sulphate-based composition comprising urea ammonium sulphate and a urease inhibitor of the type phosphoric triamide; [0191] wherein the urease inhibitor of the type phosphoric triamide is in liquid form, has a half-life time for nBTPT of only a few days when stored in bags at room temperature (20-25 C.); [0192] wherein the urease inhibitor of the type phosphoric triamide is in a solid particulate form, has a half-life time for nBTPT up to 4 months when stored in bags at room temperature (20-25 C.); [0193] wherein the urease inhibitor of the type phosphoric triamide is in a solid particulate form, and it comprises an alkaline or alkaline-forming inorganic or organic compound and a moisture repellent coating, has a half-life time for nBTPT up to over 6-12 months when stored in bags at room temperature (20-25 C.),

Example 7

[0194] This example shows that a homogeneous, solid, particulate, urea ammonium sulphate-based composition comprising urea ammonium sulphate and a urease inhibitor of the type phosphoric triamide, wherein the urea ammonium sulphate-based composition is further characterized in that: [0195] a) it comprises one or more alkaline or alkaline-forming inorganic or organic compounds that is able to interact with ammonium sulphate; and/or [0196] b) the urease inhibitor of the type phosphoric triamide is in a solid particulate form; and/or [0197] c) an anti-caking and/or moisture repellent coating is applied onto the urea ammonium sulphate particulate material,
has an efficient reduced amount of ammonia volatile losses on different soils (2 types shown) when compared to urea ammonium sulphate particulate material without the addition of a urease inhibitor of the type phosphoric triamide.

[0198] FIG. 13 shows the cumulated volatile ammonia losses (mg N/pot) on Rheinland soil (pH 6.5) and Palencia soil (pH 7.5) of urea versus UAS with and without the addition of nBTPT and with and without the addition of calcium oxide or zinc oxide. The experiments were done in three replicate.