ZINC COATED UREA FERTILIZER

Abstract

A fertilizer granule containing a core containing a nitrogen containing fertilizer such as urea and a coat on the core, the coat containing an organic zinc (Zn) complex and an inorganic Zn compound, and methods of making and using the fertilizer granule.

Claims

1. A fertilizer granule comprising: a core comprising urea; and a coat comprising an organic zinc (Zn) complex and an inorganic Zn compound, the coat forming a coating on an outer surface of the core.

2. The fertilizer granule of claim 1, wherein the organic Zn complex is a chelated Zn complex.

3. The fertilizer granule of claim 2, wherein the chelated Zn complex comprises Zn chelated with a chelator selected from ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), hydroxyethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), 1,2-diaminocyclohexane tetraacetic acid (DCTA), ethylenediamine di-o-(hydroxyphenylacetic) acid (EDDHA), ethylene glycol bis(aminoethylether) tetraacetic acid, or dihydroxyethyl glycine (DHEG), or a salt thereof, or any combination thereof.

4. The fertilizer granule of claim 1, wherein the inorganic Zn compound comprises ZnO, ZnSO.sub.4, ZnCO.sub.3, Zn(NO.sub.3).sub.2, ZnCl.sub.2, or any combination thereof.

5. The fertilizer granule of claim 1, wherein the coat comprises a first coating layer comprising the organic Zn complex and a second coating layer comprising the inorganic Zn compound, wherein the first coating layer and the second coating layer form separate coating layers on the core.

6. The fertilizer granule of claim 5, wherein at least a portion of the first coating layer is arranged between the core and the second coating layer.

7. The fertilizer granule of claim 1, wherein the inorganic Zn compound is comprised in micronized particles.

8. The fertilizer granule of claim 7, wherein the micronized particles have an average diameter of 0.1 μm to 100 μm.

9. The fertilizer granule of claim 1, wherein the core has a diameter of 1 mm to 5 mm.

10. The fertilizer granule of claim 1, comprising 98.6 wt. % to 99.9 wt. % of urea.

11. The fertilizer granule of claim 1, comprising 0.01 wt. % to 0.2 wt. % of Zn, calculated using the total amount of Zn atoms in the granule.

12. The fertilizer granule of claim 1, wherein the organic zinc (Zn) complex is (NH.sub.4).sub.2ZnEDTA (Diammonium [[N,N′-ethylenebis[N-(carboxylatomethyl)glycinato]](.sup.4−)-N,N′,O,O′,ON,ON′]zincate(.sup.2−)) and/or (Na).sub.2ZnEDTA (Disodium [[N,N′-ethylenebis[N-(carboxylatomethyl)glycinato]](4−)-N,N′,O,O′,ON,ON′]zincate(2−)).

13. The fertilizer granule of claim 1, comprising 99 wt. % to 99.9 wt. % of urea, 0.01 wt. % to 0.6 wt. % of ZnEDTA, and 0.01 wt. % to 0.2 wt. % of ZnO and/or ZnSO.sub.4.

14. The fertilizer granule of claim 1, wherein the core further comprises an urease inhibitor, and/or a nitrification inhibitor.

15. The fertilizer granule of claim 14, wherein the core comprises an 0.02 wt. % to 0.1 wt. % of the urease inhibitor, and/or 0.1 wt. % to 1 wt. % of the nitrification inhibitor, based on the weight of the core.

16. The fertilizer granule of claim 14, wherein the urease inhibitor comprises N-(n-butyl) thiophosphoric triamide (NBPT) and/or the nitrification inhibitor comprises dicyandiamide (DCD).

17. The fertilizer granule of claim 1, comprised in a fertilizer blend or a compounded fertilizer.

18. A method of making the fertilizer granule of claim 1, the method comprising: forming or providing a core comprising urea; coating an outer surface of the core with an organic Zn complex to form an organic Zn coated core; and coating an outer surface of the organic Zn coated core with micronized particles comprising an inorganic Zn compound to form the fertilizer granule.

19. The method of claim 18, wherein an aqueous solution comprising 1 wt. % to 20 wt. % of the organic Zn complex is coated on the outer surface of the core to form the organic Zn coated core.

20. A method of fertilizing, the method comprising applying a fertilizer granule of claim 1 to at least a portion of a soil, a crop, or the soil and the crop.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Advantages of the present invention may become apparent to those skilled in the art with the benefit of the following detailed description and upon reference to the accompanying drawings. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings. The drawings may not be to scale.

[0062] FIG. 1A fertilizer granule according an example of the present invention.

[0063] FIG. 2 illustrates a flowchart of a method for producing a fertilizer granule according to an example of the present invention.

[0064] FIG. 3 illustrates a schematic of a system for producing a fertilizer granule according to an example of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0065] The fertilizer blend of the present invention can contain Zn coated nitrogen containing fertilizer granules. As illustrated in a non-limiting manner in Example 1, it was found that coating an organic Zn complex coated nitrogen fertilizer containing core with micronized particles containing an inorganic Zn compound, reduced the stickiness and curing time prior bagging of the granules and increased the processibility of the granules. Relatively less reduction in nitrogen content and decrease in value addition of the product is obtained with the compositions and methods of the present invention.

[0066] These and other non-limiting aspects of the present invention are discussed in further detail in the following sections.

A. Fertilizer Granules

[0067] The fertilizer granule can contain a core and a coat forming a coating on the core. The fertilizer granule can contain 99 wt. % to 99.9 wt. % of the core e.g. the core comprises 99 wt. % to 99.9 wt. % of the fertilizer granule. The core can contain a nitrogen containing fertilizer such as urea. In some aspects, the core can contain 98.9 wt. % to 100 wt. % or at least any one of, equal to any one of, or between any two of 98.9 wt. %, 99 wt. %, 99.1 wt. %, 99.2 wt. %, 99.3 wt. %, 99.4 wt. %, 99.5 wt. %, 99.6 wt. %, 99.7 wt. %, 99.8 wt. %, 99.9 wt. %, and 100 wt. % of a nitrogen containing fertilizer such as urea, based on the weight of the core. The core can optionally contain a urease inhibitor and/or a nitrification inhibitor. In some aspects, the urease inhibitor can be a thiophosphoric triamide derivative, such as N-(n-butyl) thiophosphoric triamide (NBPT). In some aspects, the core can contain 0.02 wt. % to 0.1 wt. % or at least any one of, equal to any one of, or between any two of 0, 0.02 wt. %, 0.03 wt. %, 0.04 wt. %, 0.05 wt. %, 0.06 wt. %, 0.07 wt. %, 0.08 wt. %, 0.09 wt. %, and 0.1 wt. % of the urease inhibitor such as NBPT, based on the weight of the core. In some aspects, the nitrification inhibitor can be 3,4-dimethylpyrazole phosphate (DMPP), thio-urea (TU), dicyandiamide (DCD), 2-Chloro-6-(trichloromethyl)-pyridine (Nitrapyrin), 5-Ethoxy-3-trichloromethyl-1,2,4-thiadiazol (Terrazole), 2-Amino-4-chloro-6-methyl-pyrimidine (AM), 2-Mercapto-benzothiazole (MBT), or 2-Sulfanimalamidothiazole (ST) or any combination thereof, preferably DCD. In some aspects, the core can contain 0.1 wt. % to 1 wt. % or at least any one of, equal to any one of, or between any two of 0 wt. %, 0.1 wt. %, 0.2 wt. %, 0.3 wt. %, 0.4 wt. %, 0.5 wt. %, 0.6 wt. %, 0.7 wt. %, 0.8 wt. %, 0.9 wt. %, and 1 wt. % of the nitrification inhibitor such as DCD, based on the weight of the core. In some aspects, the core does not contain or is substantially free of a binder, filler, pH buffer, urease inhibitor, and/or nitrification inhibitor. In some aspects, the core consist of or essentially consists of urea.

[0068] The core can be of any suitable shape. Non-limiting shape includes spherical, cuboidal, cylindrical, puck shape, oval, and oblong shapes. In some aspects, the core can be of cylindrical shape with a circular, elliptical, ovular, triangular, square, rectangular, pentagonal, or hexagonal cross section, although cylindrical shaped core having a cross-section of other shapes can also be made. In some aspects, the core can have a dimension such as length, width, height and/or cross-sectional diameter between 0.5 mm to 5 mm or at least any one of, equal to any one of, or between any two of 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, and 5 mm. In some particular aspects, the core can have a substantially spherical shape with an average diameter 1 mm to 5 mm or at least any one of, equal to any one of, or between any two of 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, and 5 mm.

[0069] The fertilizer granule can contain 0.1 wt. % to 1 wt. % of the coat e.g. the coat comprises 0.1 wt. % to 1 wt. % of the fertilizer granule. The coat can contain Zn. The coat can contain a single coating layer or at least two coating layers, a first coating layer and a second coating layer. The first and the second coating layer can form separate coating layers on the core. The first coating layer can form a coating over at least a portion of an outer surface of the core. In some aspects, the first coating layer can form a relatively uniform coating layer over the core. The second coating layer can form a coating over at least a portion of an outer surface of the first coating layer coated core. At least a portion of the first coating layer can be positioned between the core and the second coating layer. In some aspects, the second coating layer can form an outer coating layer of the fertilizer granule.

[0070] The core can be coated by a single coating layer containing a mixture of an organic Zn complex and an inorganic Zn compound. When there are two or more coat layers, the first coating layer can contain either one or more organic Zn complex or one or more inorganic Zn compound and the second coating layer can contain the other. In some aspects, the first coating layer can include one or more chelated Zn complex(es) and the second coating layer can contain one or more inorganic Zn compound. In some aspects, the organic Zn complex can be a chelated Zn complex. In some aspects, the chelated Zn complex can contain Zn chelated with a chelator selected from ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic nitilotriacetic acid (NTA), hydroxyethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic diethylenetriaminepetaacetic acid (DTPA), 1,2-diaminocyclohexane tetraacetic acid (DCTA), ethylenediamine di-o-(hydroxyphenylacetic) acid ethylenediamine di-(o-hydroxyphenyleacetic acid (EDDHA), ethylene glycol bisd(aminoethylether) tetraacetic acid, or dihydroxyethyl glycine (DHEG), or a salt thereof, or any combination thereof. In some particular aspects, the chelated Zn complex can be Zn chelated with EDTA (ZnEDTA). The ZnEDTA can be Zn.sub.2EDTA and/or a ZnEDTA salt such as Na.sub.2ZnEDTA and/or (NH.sub.4).sub.2ZnEDTA. In some particular aspects, the chelated Zn complex can be Na.sub.2ZnEDTA and/or (NH.sub.4).sub.2ZnEDTA. In some aspects, the first coating layer can include one or more chelated Zn complex(es). The second coating layer can contain an inorganic Zn compound. In some aspects, the second coating layer can contain micronized particles containing the inorganic Zn compound. In some aspects, the inorganic Zn compound can include ZnO, ZnSO.sub.4, ZnCO.sub.3, Zn(NO.sub.3).sub.2, ZnCl.sub.2, or any combination thereof. In some aspects, the inorganic Zn compound can be ZnO, and/or ZnSO.sub.4. In some aspects, the micronized particles can have an average size e.g. an average diameter of 0.1 μm to 100 μm, or 0.3 μm to 50 μm, or 0.3 μm to 30 μm or at least any one of, equal to any one of, or between any two of 0.1 μm, 0.3 μm, 0.5 μm, 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, and 100 μm. In some aspects, the coat does not contain or is substantially free of a binder, filler, pH buffer, talc, anticaking agent, urease inhibitor, and/or nitrification inhibitor. In some aspects, the molar ratio of the organic Zn complex and the inorganic Zn compound in the coat and the fertilizer granule can be 0.75:1 to 1.25:1 or at least any one of, equal to any one of, or between any two of 0.75:1, 0.8:1, 0.85:1, 0.9:1, 0.95:1, 1:1, 1.05:1, 1.1:1, 1.15:1, 1.2:1, and 1.25:1.

[0071] The first coating layer can cover 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, 100% of the outer surface of the core. The second coating layer can cover 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, 100% of the outer surface of the first coating layer core. The coat overall can over 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, 100% of the outer surface of the core. FIG. 1 shows a fertilizer granule 100 according an example of the present invention, containing a core 101, an organic Zn complex containing first coating layer 102 coating an outer surface of the core, and a second coating layer 103 containing micronized particles containing inorganic Zn coating an outer surface of the first coating layer coated core. The first coating layer 102 is represented as covering the entire outer surface of the core 101, although fertilizer granules with the first coating layer 102 covering a portion of the outer surface of the core can readily be made. The second coating layer 103 is represented as covering the entire outer surface of the first coating layer coated core, although fertilizer granules with second layer coating layer 103 covering a portion of the outer surface of the first coating layer coated core can readily be made.

[0072] In some particular aspects, the fertilizer granule can contain 98.6 wt. % to 99.9 wt. % or at least any one of, equal to any one of, or between any two of 98.6 wt. %, 99 wt. %, 99.1 wt. %, 99.2 wt. %, 99.3 wt. %, 99.4 wt. %, 99.5 wt. %, 99.6 wt. %, 99.7 wt. %, 99.8 wt. % and 99.9 wt. % of the nitrogen fertilizer such as urea of the fertilizer granule, and 0.01 wt. % to 0.2 wt. % or at least any one of, equal to any one of, or between any two of 0.01 wt. %, 0.02 wt. %, 0.03 wt. %, 0.04 wt. %, 0.05 wt. %, 0.06 wt. %, 0.07 wt. %, 0.08 wt. %, 0.09 wt. %, 0.1 wt. %, 0.11 wt. %, 0.12 wt. %, 0.13 wt. %, 0.14 wt. %, 0.15 wt. %, 0.16 wt. %, 0.17 wt. %, 0.18 wt. %, 0.19 wt. %, and 0.2 wt. % of Zn, calculated using the total amount of atoms of zinc in the fertilizer granule.

[0073] In some aspects, the fertilizer granule can contain i) 99 wt. % to 99.9 wt. % or at least any one of, equal to any one of, or between any two of 99 wt. %, 99.1 wt. %, 99.2 wt. %, 99.3 wt. %, 99.4 wt. %, 99.5 wt. %, 99.6 wt. %, 99.7 wt. %, 99.8 wt. % and 99.9 wt. % of urea, ii) 0.01 wt. % to 0.9 wt. % or at least any one of, equal to any one of, or between any two of 0.01 wt. %, 0.02 wt. %, 0.03 wt. %, 0.04 wt. %, 0.05 wt. %, 0.06 wt. %, 0.07 wt. %, 0.08 wt. %, 0.09 wt. %, 0.1 wt. %, 0.2 wt. %, 0.3 wt. %, 0.4 wt. %, 0.5 wt. %, 0.6 wt. %, 0.7 wt. %, 0.8 wt. %, and 0.9 wt. % of the organic Zn complex, such as ZnEDTA and iii) 0.01 wt. % to 0.2 wt. % or 0.01 wt. % to 0.3 wt. % or, at least any one of, equal to any one of, or between any two of 0.01 wt. %, 0.02 wt. %, 0.03 wt. %, 0.04 wt. %, 0.05 wt. %, 0.06 wt. %, 0.07 wt. %, 0.08 wt. %, 0.09 wt. %, 0.1 wt. %, 0.11 wt. %, 0.12 wt. %, 0.13 wt. %, 0.14 wt. %, 0.15 wt. %, 0.16 wt. %, 0.17 wt. %, 0.18 wt. %, 0.19 wt. %, 0.2 wt. %, 0.21 wt. %, 0.22 wt. %, 0.23 wt. %, 0.24 wt. %, 0.25 wt. %, 0.26 wt. %, 0.27 wt. %, 0.28 wt. %, 0.29 wt. %, and 0.3 wt. % of the inorganic Zn compound such as ZnO and/or ZnSO.sub.4. In some aspects, the fertilizer granule can contain i) 99 wt. % to 99.9 wt. % or at least any one of, equal to any one of, or between any two of 99 wt. %, 99.1 wt. %, 99.2 wt. %, 99.3 wt. %, 99.4 wt. %, 99.5 wt. %, 99.6 wt. %, 99.7 wt. %, 99.8 wt. % and 99.9 wt. % of urea, ii) 0.002 wt. % to 0.15 wt. % or at least any one of, equal to any one of, or between any two of 0.002 wt. %, 0.003 wt. %, 0.004 wt. %, 0.005 wt. %, 0.006 wt. %, 0.007 wt. %, 0.008 wt. %, 0.009 wt. %, 0.01 wt. %, 0.02 wt. %, 0.03 wt. %, 0.04 wt. %, 0.05 wt. %, 0.06 wt. %, 0.07 wt. %, 0.08 wt. %, 0.09 wt. %, 0.1 wt. %, 0.11 wt. %, 0.12 wt. %, 0.13 wt. %, 0.14 wt. %, and 0.15 wt. % of the organic Zn (e.g., present as and/or provided as organic Zn complex) and iii) 0.006 wt. % to 0.18 wt. % or at least any one of, equal to any one of, or between any two of 0.006 wt. %, 0.007 wt. %, 0.008 wt. %, 0.009 wt. %, 0.01 wt. %, 0.02 wt. %, 0.03 wt. %, 0.04 wt. %, 0.05 wt. %, 0.06 wt. %, 0.07 wt. %, 0.08 wt. %, 0.09 wt. %, %, 0.1 wt. %, 0.11 wt. %, 0.12 wt. %, 0.13 wt. %, 0.14 wt. %, 0.15 wt. %, 0.16 wt. %, 0.17 wt. %, and 0.18 wt. % of the inorganic Zn (e.g. present as and/or provided as inorganic Zn compound).

[0074] In some aspects, the core and/or coat contains a filler, binder, and/or pH buffer. In some aspects, the core and/or coat contains, based on total weight of the core and/or coat respectively, less than 0.5 wt. % or less than 0.1 wt. % or is substantially free of a filler such as each of silica, dried distillers grains with solubles (DDGS), CaCO.sub.3, MgO, CaO, bone mill powder, and rice husk. In some aspects, the core and/or coat contains based on total weight of the core and/or coat respectively less than 0.5 wt. % or less than 0.1 wt. % or is substantially free of a binder such as each of plaster of paris, flour, chalk powder, bleached wheat flour, starch, gluten, kaolin, bentonite, and colloidal silica. In some aspects, core and/or coat contains based on total weight of the core and/or coat respectively less than 0.5 wt. % or less than 0.1 wt. % or is substantially free of a pH buffer such as each of CaCO.sub.3, Na.sub.2CO.sub.3, K.sub.2CO.sub.3, MgO, KH.sub.2PO.sub.4, NaHCO.sub.3, and/or MgCO.sub.3.

[0075] In some aspects, additional fertilizer substances besides urea can be included or excluded in the core of the fertilizer granules. If included, additional fertilizers can be chosen based on the particular needs of certain types of soil, climate, or other growing conditions to maximize the efficacy of the fertilizer granule in enhancing plant growth and crop yield. Additional additives may also be included or excluded in the fertilizer granules. Non-limiting examples of additives that can be included or excluded from the fertilizer granules of the present invention include micronutrients, additional nitrogen nutrients, and/or secondary nutrients. A micronutrient is a botanically acceptable form of an inorganic or organometallic compound such as boron, copper, iron, chloride, manganese, molybdenum, nickel, or zinc. An additional nitrogen nutrient is a nutrient other than urea can deliver nitrogen to a plant. In some aspects, the additional nitrogen nutrient can include ammonium nitrate, ammonium sulfate, diammonium phosphate, monoammonium phosphate, urea-formaldehyde, ammonium chloride, and potassium nitrate. A secondary nutrient is a substance that can deliver calcium, magnesium, and/or sulfur to a plant. In some aspects, the secondary nutrients may include lime, gypsum, superphosphate, or a combination thereof.

[0076] The core of the fertilizer granules can have desirable physical properties such as desired levels of abrasion resistance, granule strength, pelletizability, hygroscopicity, granule shape, and size distribution, which are important properties for the fertilizer core.

[0077] The fertilizer granules described herein can be comprised in a composition useful for application to soil. In addition to the fertilizer granules, the composition may include other fertilizer compounds, micronutrients, primary nutrients, additional urea, additional nitrogen nutrients, insecticides, herbicides, or fungicides, or combinations thereof.

[0078] The fertilizer granules described herein can also be included in a blended composition comprising other fertilizer granules. The other fertilizer granules can be granules of urea, monoammonium phosphate (MAP), diammonium phosphate (DAP), muriate of potash (MOP), monopotassium phosphate (MKP), triple super phosphate (TSP), rock phosphate, single super phosphate (SSP), ammonium sulfate and like.

B. Method of Making a Fertilizer Granule

[0079] The method for making a fertilizer granule can include providing or forming a core containing a nitrogen containing fertilizer such as urea, contacting and coating at least a portion of an outer surface of the core with an organic Zn complex to form an organic Zn coated core, e.g. first coating layer coated core, and contacting and coating at least a portion of an outer surface of the organic Zn coated core with an inorganic Zn compound to form the fertilizer granule. In certain aspects, at least a portion of the outer surface of the core can be contacted with a solution containing the organic Zn complex. In certain aspects, the solution can be an aqueous solution containing 1 wt. % to 20 wt. %, or at least any one of, equal to any one of, or between any two of 1 wt. %, 2 wt. %, 3 wt. %, 4 wt. %, 5 wt. %, 6 wt. %, 7 wt. %, 8 wt. %, 9 wt. %, 10 wt. %, 11 wt. %, 12 wt. %, 13 wt. %, 14 wt. %, 15 wt. %, 16 wt. %, 17 wt. %, 18 wt. %, 19 wt. % and 20 wt. % of the organic Zn complex, such as ZnEDTA. In certain aspects, pH of the aqueous solution can be 6 to 8. In certain aspects, micronized particles containing the inorganic Zn compound can be contacted with the at least a portion of the outer surface of the organic Zn coated core to form the fertilizer granule. In some aspects, the core can be contacted e.g. with 1 kg to 5 kg or at least any one of, equal to any one of, or between any two of 1 kg, 2 kg, 3 kg, 4 kg, and 5 kg of the organic Zn complex solution for per ton of nitrogen fertilizer such as urea in the core. In some aspects, the core can be contacted with 0.1 kg to 0.5 kg, or at least any one of, equal to any one of, or between any two of 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, and 0.5 kg, of the organic Zn complex per ton of the nitrogen fertilizer in the core. In some aspects, the core can be contacted with 0.02 kg to 0.09 kg, or at least any one of, equal to any one of, or between any two of 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, and 0.09 kg of the organic Zn (e.g. provided as organic Zn complex) per ton of the nitrogen fertilizer in the core. In some aspects, the organic Zn coated core can be contacted e.g. coated with 0.1 kg to 2 kg or 0.1 kg to 3 kg or at least any one of, equal to any one of, or between any two of 0.1 kg, 0.2 kg, 0.3 kg, 0.4 kg, 0.5 kg, 0.6 kg, 0.7 kg, 0.8 kg, 0.9 kg, 1 kg, 1.1 kg, 1.2 kg, 1.3 kg, 1.4 kg, 1.5 kg, 1.6 kg, 1.7 kg, 1.8 kg, 1.9 kg, 2 kg, 2.1 kg, 2.2 kg, 2.3 kg, 2.4 kg, 2.5 kg, 2.6 kg, 2.7 kg, 2.8 kg, 2.9 kg, and 3 kg of the inorganic Zn compound for per ton of nitrogen fertilizer such as urea in the core. In some aspects, the organic Zn coated core can be contacted e.g. coated with 0.06 kg to 1.8 kg or at least any one of, equal to any one of, or between any two of 0.06 kg, 0.07 kg, 0.08 kg, 0.09 kg, 0.1 kg, 0.2 kg, 0.3 kg, 0.4 kg, 0.5 kg, 0.6 kg, 0.7 kg, 0.8 kg, 0.9 kg, 1 kg, 1.1 kg, 1.2 kg, 1.3 kg, 1.4 kg, 1.5 kg, 1.6 kg, 1.7 kg, and 1.8 kg of the inorganic Zn (e.g. provided as inorganic Zn compound) for per ton of nitrogen fertilizer such as urea in the core. FIG. 2 shows a flow chart of a method 200 for making a fertilizer granule according to an example of the present invention. Referring to FIG. 2, a urea granule 201 can be coated with a solution containing an organic Zn complex 202 to form an organic Zn coated core 203, the organic Zn coated core 203 can be coated with micronized particles containing an inorganic Zn complex 204 to form a Zn coated urea fertilizer granule 205.

[0080] In some particular aspects, a core in a form of urea prills or granules of size 1 mm to 5 mm can be provided in a container, such as a drum coater. An aqueous solution containing 5 wt. % to 15 wt. % of an organic Zn complex such as ZnEDTA can be sprayed on the urea granules in the container to form the organic Zn coated core e.g. ZnEDTA coated urea. Micronized particles containing an inorganic Zn compound such as ZnO and/or ZnSO.sub.4 can be added to the container to coat the ZnEDTA coated urea with the micronized particles. In some aspects, the container e.g. drum can be rotated at 10 to 40 RPM during coating of the organic Zn complex and/or the inorganic Zn compound to relatively evenly distribute the organic Zn complex and/or inorganic Zn compound over the outer surfaces of the nitrogen fertilizer containing core and/or ZnEDTA coated nitrogen fertilizer, respectively. FIG. 3 illustrates a schematic of a system for producing a fertilizer granule according to an example of the present invention. Referring to FIG. 3, 1 is a pam drum, 2 are Zn coated urea granules, 3 is a motor gear box, 4 is a peristatic pump, 5 is a feed tank, 6 is a spray nozzle, 7 is a hot air inlet, 8 is an air exhaust system, 9 shows rotation of pan drum 1, 10 is a temperature controller, and 11 is an atomizing spray.

[0081] The core can be a prill or formed by granulating, pelletizing, compacting, and/or extruding a composition containing the core ingredients such as urea and optionally a urease inhibitor and/or a nitrification inhibitor.

[0082] In some aspects, the granulation process of core formation can include granulating a powder composition containing the core ingredients.

[0083] In some aspects, the pelletizing process of core formation can include forming a powdered composition containing the core ingredients and pressing the powdered composition through a die to form a pelletized core of a desired shaped. The pelletizing process can be performed using a pelletizing press known in the art. In some aspects, the core ingredients can be mixed in a mixer, such as a turbo mixer to form the powdered composition, the powdered composition from the mixer can be fed to a screw feeder connected to a pelletizing press. In some aspects, the powdered composition can be fed to the screw feeder at a rate 40 kg/hr to 100 kg/h, or 50 kg/hr to 80 kg/h. In some aspects, the pelletizing press can include twin rollers rotating at a speed 150 to 200 RPM and the powdered composition can be pressed through the die by the rollers.

[0084] In some aspects, the compacting process of core formation can include, forming a powdered composition by mixing the core ingredients in dry form, compacting the powdered composition to form a compacted composition and crushing, grinding, and/or granulating the compacted composition to form the core of desired shape and size. The compacting process can be done using a roller compactor known in the art. In some aspects, the powdered composition can be compacted by feeding the powdered composition into a roller compactor containing a rotating roller and a roller in immobile phase, and forming a compacted composition in form of a sheet from the powdered composition.

[0085] In some aspects, the extrusion process of core formation can include, forming a extrudable composition containing the core ingredients, and extruding the extrudable composition. The method may also include a drying step after extruding to remove solvent that may have been added to make the composition extrudable. In some aspects, the extrudable composition can be formed by the core ingredients in dry form and adding any solvent, if needed. In some aspects, the solvent can be water. The extrusion can be done using suitable extruder apparatus known in the art and can be performed at a temperature between 0° C. and 150° C. and a screw speed from 1 to 500 rpm, wherein the extruder comprises a multi-feeder comprising extrusion components including a main drive, shaft, screw, barrel, and/or die.

C. Methods of Using Fertilizer Granules

[0086] The fertilizer granule(s) and fertilizer blend containing the fertilizer granule(s) of the present invention can be used in methods of increasing the amount of i) nitrogen and ii) Zn in soil and of enhancing plant growth. Such methods can include applying to the soil an effective amount of a composition comprising the fertilizer granule(s) of the present invention. The method may include increasing the growth and yield of crops, trees, ornamentals, etc. such as, for example, palm, coconut, rice, wheat, corn, barley, oats, and soybeans. The method can include applying the fertilizer blend of the present invention to at least one of a soil, an organism, a liquid carrier, a liquid solvent, etc.

[0087] Non-limiting examples of plants that can benefit from the fertilizer of the present invention include vines, trees, shrubs, stalked plants, ferns, etc. The plants may include orchard crops, vines, ornamental plants, food crops, timber, and harvested plants. The plants may include Gymnosperms, Angiosperms, and/or Pteridophytes. The Gymnosperms may include plants from the Araucariaceae, Cupressaceae, Pinaceae, Podocarpaceae, Sciadopitaceae, Taxaceae, Cycadaceae, and Ginkgoaceae families. The Angiosperms may include plants from the Aceraceae, Agavaceae, Anacardiaceae, Annonaceae, Apocynaceae, Aquifoliaceae, Araliaceae, Arecaceae, Asphodelaceae, Asteraceae, Berberidaceae, Betulaceae, Bignoniaceae, Bombacaceae, Boraginaceae, Burseraceae, Buxaceae, Canellaceae, Cannabaceae, Capparidaceae, Caprifoliaceae, Caricaceae, Casuarinaceae, Celastraceae, Cercidiphyllaceae, Chrysobalanaceae, Clusiaceae, Combretaceae, Cornaceae, Cyrillaceae, Davidsoniaceae, Ebenaceae, Elaeagnaceae, Ericaceae, Euphorbiaceae, Fabaceae, Fagaceae, Grossulariaceae, Hamamelidaceae, Hippocastanaceae, Illiciaceae, Juglandaceae, Lauraceae, Lecythidaceae, Lythraceae, Magnoliaceae, Malpighiaceae, Malvaceae, Melastomataceae, Meliaceae, Moraceae, Moringaceae, Muntingiaceae, Myoporaceae, Myricaceae, Myrsinaceae, Myrtaceae, Nothofagaceae, Nyctaginaceae, Nyssaceae, Olacaceae, Oleaceae, Oxalidaceae, Pandanaceae, Papaveraceae, Phyllanthaceae, Pittosporaceae, Platanaceae, Poaceae, Polygonaceae, Proteaceae, Punicaceae, Rhamnaceae, Rhizophoraceae, Rosaceae, Rubiaceae, Rutaceae, Salicaceae, Sapindaceae, Sapotaceae, Simaroubaceae, Solanaceae, Staphyleaceae, Sterculiaceae, Strelitziaceae, Styracaceae, Surianaceae, Symplocaceae, Tamaricaceae, Theaceae, Theophrastaceae, Thymelaeaceae, Tiliaceae, Ulmaceae, Verbenaceae, and/or Vitaceae family.

[0088] The effectiveness of compositions comprising the fertilizer granule(s) of the present invention can be ascertained by measuring the amount of nitrogen and Zn in the soil at various times after applying the fertilizer composition to the soil. It is understood that different soils have different characteristics, which can affect the stability of the nitrogen in the soil. The effectiveness of a fertilizer composition can also be directly compared to other fertilizer compositions by doing a side-by-side comparison in the same soil under the same conditions.

EXAMPLES

[0089] The present invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes only, and are not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of noncritical parameters which can be changed or modified to yield essentially the same results.

Example 1

[0090] Fertilizer Granule Preparation

[0091] Zn coated urea fertilizer granules were formed in a drum coater system. Series of coating studies were done to evaluate the processibility of coating material and addition of dry powders to mitigate the stickiness of the coated product.

[0092] A lab scale drum coater with a capacity of 200 grams to 2 kilograms with a drum interchanging facility based on the required volume was used. The drum contained four baffles 0.5 inch in height and 1 inch in width across the drum length. The baffles were placed at 45 angles from the center. The drum coater system worked in manual and automatic mode starting from feeding, pumping, spraying, exhausting, drying, and discharge the coated material. Based on the formulation desired, the required amount of sieved (>1.00 mm and <4.00 mm) granular urea was weighed and fed into the drum. Then the drum was rotated at 15 to 20 RPM for 5 minutes. The drum coating process was performed in a batch process. (NH.sub.4).sub.2ZnEDTA and inorganic Zn (ZnO and ZnSO.sub.4) based powder were obtained from commercial sources as raw materials for the coating process. An aqueous ZnEDTA solution containing 9 wt. % of (NH.sub.4).sub.2ZnEDTA was obtained. The pH of the solution was 6-8. The ZnEDTA solution was pumped using a peristatic pump into the drum containing urea. The pump was connected with a spray nozzle with orifice design, which atomized the solution by compressed air. An exhaust pipe line on the top of the drum took off the compressed air. The solution was sprayed with the spray nozzle on the granular urea in the drum. After spray coating, the pump was stopped and the drum was rotated for about five more minutes to ensure the dispersion of the liquid coating. Then inorganic Zn powder, containing 62 wt. % of Zn, was added into the drum. The drum rotation was continued for about 3 minutes before the coated product was collected for packing. Two experiments were performed. In one experiment (experiment 1), 2.8-3.0 kg of (NH.sub.4).sub.2ZnEDTA solution for per ton of urea in the drum, and 0.5 kg of inorganic Zn powder for per ton of urea in the drum was added during the coating process. In the other experiment (experiment 2), 2.8-3.0 kg of (NH.sub.4).sub.2ZnEDTA solution for per ton of urea in the drum, and 1.5 kg of inorganic Zn powder for per ton of urea in the drum was added during the coating process.

[0093] A flowchart of a method for producing a fertilizer granule according to Example 1 is shown in FIG. 2. A schematic of the coating system and process of Example 1 is shown in FIG. 3. The coating process parameters are presented in Table 1. Table 2 shows the physical properties of the urea granules, ZnEDTA coated urea, and fertilizer granule of Example 1 (inorganic Zn coated ZnEDTA coated urea). As it can be seen from Table 2, the fertilizer granules according to Example 1 show good physical properties. The coated fertilizer granules of the present invention showed higher crushing strength and reduced stickiness, compared to only ZnEDTA coated urea granules. The coated fertilizer granules of the present invention is expected to require reduced or no curing time prior to bagging.

TABLE-US-00001 TABLE 1 Coating process parameters Process parameters Drum RPM 20 Spray nozzle diameter 2 mm Spray rate 8 ml/min Spray nozzle type orifice Number of openings in orifice  6 Spray nozzle distance from the coating bed 300 to 600 mm Atomizing air pressure 0.1 bar

TABLE-US-00002 TABLE 2 Physical properties of the urea granules, ZnEDTA coated urea, and fertilizer granule of Example 1 Crushing Weight loss Moisture strength due to Abrasion content Sample ID (Kgf) (wt %) (wt %) Urea granules 2.920 0.012 0.336 ZnEDTA coated Urea 2.381 0.042 0.653 Fertilizer granules of 2.547 0.045 0.477 example 1-experiment 1, (Inorganic Zn and ZnEDTA coated Urea) Fertilizer granules of 2.70 0.050 0.336 example 1-experiment 2, (Inorganic Zn and ZnEDTA coated Urea)