Urea calcium sulfate coated urea fertilizers and blends thereof

Abstract

Disclosed is a fertilizer granule comprising a core comprising at least 90 wt% urea and a shell comprising a urea calcium sulfate (UCS) adduct, wherein the shell covers at least a portion of the outer surface of the core, and blends of the fertilizer granule with other fertilizers. Also disclosed are methods of making and using the fertilizer granule and blends.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 129843, filed December 23, 2020, which is incorporated herein by reference in its entirety. Background of the Invention

[0004] A. Field of Invention

[0005] This invention generally relates to coated urea fertilizer granules. In particular, this invention relates to urea fertilizer granules coated with urea calcium sulfate adduct and blends thereof.

[0006] B. Relevant Technical Specifications

[0007] Soil nutrients such as nitrogen, phosphorus, potassium, and sulfur, as well as minor and micronutrients such as calcium, iron, zinc, copper, and magnesium, are beneficial for thriving agriculture and plant growth. Through repeated planting cycles, the amount of these nutrients in the soil can be depleted, leading to stunted plant growth and reduced yields. To counteract this effect, fertilizers have been developed to help replace depleted essential nutrients and establish a proper nutrient balance.

[0008] Fertilizers containing multiple plant nutrients such as nitrogen, phosphorus, potassium, and sulfur have been used to provide a variety of nutrients through single application. However, urea, a commonly used nitrogen nutrient, is often unstable in blends with other fertilizers such as phosphorus, potassium, and sulfur fertilizers. Over time and / or during storage, these blends can form wet lumps and sticky substances, making them less suitable for use as fertilizers. Furthermore, urea can be rapidly hydrolyzed by soil bacteria in the soil. Rapid hydrolysis of urea reduces the amount of nitrogen available to plants, deteriorates soil health, and generates environmental problems such as greenhouse gas emissions and groundwater pollution.

[0009] Attempts have been made to prepare relatively stable fertilizer compositions containing urea and blends of urea and other plant nutrients. Alternative layers containing inorganic acids and bases have been used to coat and stabilize urea. For example, EP2890662A2 discloses a fertilizer composition containing urea coated with one layer of acid and one layer of base. However, to obtain relatively high urea stability, urea particles may require multiple alternating layers of inorganic acid and base coating, and other problems may arise due to the use of large amounts of acid and base. US4026696A and US4028088A disclose the use of high contents of calcium sulfate, for example, at least 10% by weight, to stabilize nitrogen fertilizers. However, using such high contents of calcium sulfate may limit the amount of other nutrients, such as nitrogen, in the fertilizer composition. Summary of the Invention

[0010] Solutions to at least some of the aforementioned problems have been found. One solution lies in providing urea granules coated with a urea-calcium sulfate (UCS) adduct. It has been found that coating urea with a UCS adduct stabilizes it. By using UCS-coated urea granules, efficient nitrogen uptake by plants and relatively low urea nitrogen loss are achieved. Furthermore, as illustrated in a non-limiting manner in the examples, fertilizer blends containing UCS-coated urea granules and other fertilizers are relatively stable over time compared to fertilizer blends containing uncoated urea granules, and form little or no agglomeration.

[0011] One aspect of the invention relates to fertilizer granules. The fertilizer granules may comprise a core and a shell covering at least a portion of the outer surface of the core. The core may comprise urea. In some aspects, based on the total weight of the core, the core may comprise at least 90% by weight of urea. The shell may comprise a urea-calcium sulfate (UCS) adduct. The UCS adduct may have the chemical formula CaSO4·4CO(NH2)2. In some aspects, based on the total weight of the shell, the shell may comprise 20% to 100% by weight, or 30% to 90% by weight, or 45% to 80% by weight of the UCS adduct.

[0012] In some aspects, the shell may contain additional urea and additional calcium sulfate, which are not contained as adducts (“in free”). In some aspects, at least 95% by weight of the shell may consist of UCS adducts, urea (e.g., in free), and calcium sulfate (e.g., in free). In some aspects, based on the total weight of the shell, the shell may contain i) 18% to 40% by weight of nitrogen (N) (e.g., from urea in free and as an adduct), ii) 2% to 18% by weight of calcium (Ca) (e.g., from calcium sulfate in free and as an adduct), and iii) 1% to 12% by weight of sulfur (S) (e.g., from calcium sulfate in free and as an adduct). In some aspects, the weight % ratio of nitrogen (N) to calcium (Ca) in the shell may be 15:1 to 1:1, preferably 5:1 to 2:1. In some aspects, the total Ca content of the fertilizer granules may be 2.8% by weight or less. In some respects, the total nitrogen (N) content of fertilizer granules can be 41% by weight or more.

[0013] The core and / or shell may also independently contain a urease inhibitor, a nitrification inhibitor, one or more minor nutrients, one or more micronutrients, or one or more binders, or any combination thereof. In some aspects, the urease inhibitor may be a triamine thiophosphate derivative, such as N-(n-butyl)thiophosphate triamine (NBPT). In some aspects, based on the total weight of the core, the core may contain 0.01% to 0.07% by weight of a urease inhibitor, such as NBPT. In some aspects, based on the total weight of the shell, the shell may contain 0.01% to 0.07% by weight of a urease inhibitor, such as NBPT. In some aspects, the nitrification inhibitor may be 3,4-dimethylpyrazole phosphate (DMPP), thiourea (TU), dicyandiamide (DCD), 2-chloro-6-(trichloromethyl)-pyridine (trichloromethylpyridine), 5-ethoxy-3-trichloromethyl-1,2,4-thiadiazole (chlorazal), 2-amino-4-chloro-6-methylpyrimidine (AM), 2-mercapto-benzothiazole (MBT) or 2-sulfathiazole (ST), or any combination thereof, preferably DCD. In some aspects, based on the total weight of the core, the core may contain 0.01% to 0.04% by weight of a nitrification inhibitor, such as DCD. In some aspects, based on the total weight of the shell, the shell may contain 0.01% to 0.04% by weight of a nitrification inhibitor, such as DCD. Micronutrients may be plant-acceptable forms of inorganic or organometallic compounds such as boron, copper, iron, chloride, manganese, molybdenum, nickel, or zinc. In some aspects, the core may contain 0.1% to 1.0% by weight of micronutrients based on its total weight. In some aspects, the shell may contain 0.1% to 1.0% by weight of micronutrients based on its total weight. Minor nutrients are substances that can transport calcium, magnesium, and / or sulfur to the plant. In some aspects, the core may contain 0.5% to 2.5% by weight of minor nutrients, such as calcium sulfate, lime, superphosphate, or any combination thereof, based on its total weight. In some aspects, in addition to calcium and sulfates present as calcium sulfate (free and as adducts), the shell may contain 0.5% to 2.5% by weight of other minor nutrients based on its total weight, such as lime, superphosphate, or any combination thereof. The binder may be gum arabic. In some aspects, the shell may contain 0.01% to 0.1% by weight of binder based on its total weight.

[0014] In some respects, the weight ratio of the core to the shell in fertilizer granules can be from 90:10 to 99.5:0.5. In some respects, the core can account for about 90% to 99.5%, 93% to 99%, or 96% to 98% of the total weight of the fertilizer granules. In some respects, the shell can account for about 0.5% to 10%, 1% to 7%, or 2% to 4% of the total weight of the fertilizer granules.

[0015] In some aspects, fertilizer granules may include an adhesive layer located between the core and at least a portion of the shell. The adhesive layer may contain a binder suitable for fertilizer. In some aspects, the binder may be gum arabic.

[0016] The core and / or fertilizer granules can be of any suitable shape. Non-limiting shapes include spherical, cubic, cylindrical, disc-shaped, elliptical, and rectangular, although cores and / or fertilizer granules with other shapes can also be prepared. In some aspects, the core and / or fertilizer granules can be spherical. In some aspects, the core and / or fertilizer granules can independently be cylinders with circular, elliptical, oval, triangular, square, rectangular, pentagonal, or hexagonal cross-sections, although cylindrical cores with other cross-sectional shapes can also be prepared. In some aspects, the fertilizer granules can have dimensions such as length, width, height, and / or cross-sectional diameter of 0.5 mm to 6 mm. In some aspects, the fertilizer granules can have a basic spherical shape with an average diameter of 0.5 mm to 5 mm, preferably 1 mm to 4 mm.

[0017] In some aspects, the shell may cover at least 10%, 20%, 30%, 40%, or 10% to 50% of the outer surface of the core. In other aspects, the shell may cover a majority (e.g., more than 50%) of the outer surface of the core. In some aspects, the shell may cover more than 50%, at least 60%, at least 70%, at least 80%, at least 90%, or 100% of the outer surface of the core. In some aspects, the shell may cover 60% to 100%, or 80% to 100%, or 90% to 100% of the outer surface of the core. In some aspects, fertilizer granules may be included in the composition. The composition may contain a plurality of fertilizer granules.

[0018] Some aspects relate to fertilizer blends. The fertilizer blend may comprise 10% to 90% by weight of a first granular fertilizer composition and 10% to 90% by weight of a second granular fertilizer composition. The first granular fertilizer composition may comprise fertilizer granules as described herein (e.g., fertilizer granules comprising a core and a shell). In some aspects, the first granular fertilizer composition may comprise a plurality of core-and-shell fertilizer granules as described herein. The second granular fertilizer composition may differ from the first granular fertilizer composition. In some aspects, the second granular fertilizer composition may comprise phosphate and / or potash fertilizers. In some aspects, the second granular fertilizer composition may comprise diammonium phosphate (DAP), superphosphate (SSP), triple superphosphate (TSP), or potassium chloride (MOP) or any combination thereof. In some aspects, the second granular fertilizer composition may comprise superphosphate (SSP), and the fertilizer blend may comprise 40% to 60% by weight of the first granular fertilizer composition and 40% to 60% by weight of SSP. In some aspects, the second granular fertilizer composition may contain superphosphate (SSP) and potassium chloride (MOP), and the fertilizer blend may contain 15% to 40% by weight of the first granular fertilizer composition, 45% to 70% by weight of SSP, and 10% to 30% by weight of MOP. In some aspects, the second granular fertilizer composition may contain diammonium phosphate (DAP) and potassium chloride (MOP), and the fertilizer blend may contain 15% to 40% by weight of the first granular fertilizer composition, 30% to 50% by weight of DAP, and 20% to 45% by weight of MOP. In some aspects, the second granular fertilizer composition may contain triple superphosphate (TSP), and the fertilizer blend may contain 40% to 60% by weight of the first granular fertilizer composition and 40% to 60% by weight of TSP.

[0019] The second granular fertilizer composition may contain particles of various shapes and sizes. Non-limiting shapes of the particles in the second granular fertilizer composition include spherical, cylindrical, disc-shaped, elliptical, or rectangular shapes. The size of the particles in the second granular fertilizer composition may be larger than, smaller than, and / or equal to the core-shell particles of the first granular fertilizer composition. In some aspects, the longest dimension of the particles in the second granular fertilizer composition may be from 0.5 mm to 8 mm. In some specific aspects, the second granular fertilizer particles may have a substantially spherical shape with a diameter from 0.5 mm to 6 mm.

[0020] In some cases, according to IFDC S-104, fertilizer blends may be stable when stored for 2, 3, 4, 5, 6, 7, 8, 9, or 10 weeks, or for 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 months (e.g., with an increase in moisture content not exceeding 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 110%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, 200%, 250%, 300%, or more than 300%, or remain free-flowing, or remain free of caking, or remain non-sticky).

[0021] One aspect of the invention relates to a method for preparing fertilizer granules, such as the core-shell fertilizer granules described herein. The method may include forming or providing a urea-containing core and coating the outer surface of the core with a UCS adduct to form fertilizer granules. In some aspects, the core may be coated with a powder material containing a UCS adduct. The powder material may comprise particles with an average size of 10 to 80 micrometers and may also comprise urea (e.g., in free form) and calcium sulfate (e.g., in free form). The powder material may be formed by grinding and / or crushing particles containing the UCS adduct. In some aspects, the core may be formed as spheres or the core may be formed by granulating, compacting, and / or granulating a composition containing urea and optionally a urease inhibitor, a nitrification inhibitor, one or more minor nutrients, and / or one or more micronutrients.

[0022] In some aspects, the core and UCS adduct, such as a powder material containing the UCS adduct, can be mixed in the presence of water to form a coating of the UCS adduct on at least a portion of the outer surface of the core, thereby forming fertilizer granules. In some aspects, the water can be hot water having a temperature of 50°C to 80°C. In some aspects, the coating can be formed by rotating the core and powder material in a container. In some aspects, 10 ml to 50 ml of water, such as hot water, can be added per 1000 g of the total weight of the core and powder material. In some aspects, the core and powder material can be premixed before adding water. In some aspects, optional shell components, such as urease inhibitors, nitrification inhibitors, one or more minor nutrients, one or more micronutrients, or one or more binders, or any combination thereof, can be added to the container, and the coating on the core (e.g., the shell) can include the optional shell components. The container can be any suitable container, including but not limited to a granulator, such as a disc granulator or a drum granulator.

[0023] In some aspects, the core can contact an adhesive to form an adhesive layer, coating at least a portion of the core's outer surface to form an adhesive-coated core. The adhesive-coated core can contact a UCS adduct, such as a powder material containing a UCS adduct, to form a coating of the UCS adduct on at least a portion of the outer surface of the adhesive-coated core, thereby forming fertilizer granules. In some aspects, the core can contact an adhesive solution containing an adhesive. The adhesive solution can be an aqueous solution containing an adhesive. This aqueous solution can contain an adhesive to water weight ratio of 0.8:1 to 1:0.8. In some aspects, the adhesive can be gum arabic. In some aspects, the core, the adhesive solution, and the UCS adduct can contact each other in a container. In some respects, optional shell components, such as urease inhibitors, nitrification inhibitors, one or more minor nutrients, one or more micronutrients, or one or more binders, or any combination thereof, may be added to the container, and the core, such as the membrane (e.g., shell) on a binder-coated core, may include optional shell components. The container can be any suitable container, including but not limited to a pelletizer, such as a disc pelletizer or a drum pelletizer.

[0024] One aspect of the present invention relates to a method for preparing a fertilizer blend. The method may include forming and / or providing a first granular fertilizer composition as described herein, providing a second granular fertilizer composition as described herein, and contacting the first granular fertilizer composition and the second granular fertilizer composition at a weight ratio of 1:9 to 9:1 to form a blend of the first granular fertilizer composition and the second granular fertilizer composition. The first granular fertilizer composition and the second granular fertilizer composition may be blended by methods known in the art.

[0025] One aspect of the invention relates to a fertilization method comprising applying the fertilizer granules and / or fertilizer blends described herein to soil, crops, or at least a portion of soil and crops. Methods for promoting plant growth are also disclosed, comprising applying to soil, plants, or soil and plants an effective amount of a composition comprising the fertilizer blends of the present invention.

[0026] The following aspects 1 to 20 of the present invention are also disclosed.

[0027] Aspect 1 is a fertilizer granule comprising: a core containing at least 90% by weight urea; and a shell containing a urea-calcium sulfate (UCS) adduct, wherein the shell covers at least a portion of the outer surface of the core, and wherein the fertilizer granule has a calcium (Ca) content of 2.8% by weight or less and / or a nitrogen (N) content of 41% by weight or more.

[0028] Aspect 2 is the fertilizer granules of aspect 1, wherein the shells contain 20% to 100% by weight of UCS adducts based on the total weight of the shells.

[0029] Aspect 3 is any fertilizer granule of aspects 1 to 2, wherein the core further contains a urease inhibitor, a nitrification inhibitor, one or more minor nutrients, or one or more micronutrients, or any combination thereof.

[0030] Aspect 4 is any of the fertilizer granules from aspects 1 to 3, wherein the shell also contains urea and calcium sulfate.

[0031] Aspect 5 is fertilizer granules of any one of aspects 1 to 4, wherein at least 95% by weight of the shell consists of UCS adduct, urea and calcium sulfate.

[0032] Aspect 6 is fertilizer granules of any one of aspects 1 to 5, wherein the weight % ratio of N to Ca in the shell is 15:1 to 1:1, preferably 5:1 to 2:1.

[0033] Aspect 7 is any fertilizer granule from aspects 1 to 6, wherein the chemical formula of the UCS adduct is CaSO4·4CO(NH2)2.

[0034] Aspect 8 is a fertilizer granule of any one of aspects 1 to 7, wherein the shell further comprises a urease inhibitor, a nitrification inhibitor, one or more minor nutrients, one or more micronutrients, or one or more binders, or any combination thereof.

[0035] Aspect 9 is a fertilizer particle of any of aspects 1 to 8, and further comprises an adhesive layer, wherein at least a portion of the adhesive layer is located between the core and the shell.

[0036] Aspect 10 is any fertilizer granule from aspects 1 to 9, wherein the weight ratio of the core to the shell is 90:10 to 99.5:0.5.

[0037] Aspect 11 is a fertilizer blend comprising: 10% to 90% by weight of a first granular fertilizer composition comprising fertilizer particles, the fertilizer particles comprising a urea-containing core and a shell containing a urea-calcium sulfate (UCS) adduct, wherein the shell covers at least a portion of the outer surface of the core; and 10% to 90% by weight of a second granular fertilizer composition, wherein the first granular fertilizer composition is different from the second granular fertilizer composition, wherein the second granular fertilizer composition is blended with the first granular fertilizer composition.

[0038] Aspect 12 is a fertilizer blend of aspect 11, wherein the first granular fertilizer composition comprises fertilizer granules from any of aspects 1 to 10.

[0039] Aspect 13 is a fertilizer blend of any one of aspects 11 to 12, wherein the second granular fertilizer composition comprises phosphate fertilizer.

[0040] Aspect 14 is a fertilizer blend of any of aspects 11 to 13, wherein the second granular fertilizer composition comprises potassium fertilizer.

[0041] Aspect 15 is a fertilizer blend of any of Aspects 11 to 14, wherein the second granular fertilizer composition comprises diammonium phosphate (DAP), superphosphate (SSP), triple superphosphate (TSP), or potassium chloride (MOP) or any combination thereof.

[0042] Aspect 16 is a fertilizer blend of any of Aspects 11 to 15, wherein the second granular fertilizer composition comprises superphosphate (SSP), and the fertilizer blend comprises 40% to 60% by weight of the first fertilizer composition and 40% to 60% by weight of SSP.

[0043] Aspect 17 is a fertilizer blend of any of Aspects 11 to 15, wherein the second granular fertilizer composition comprises superphosphate (SSP) and potassium chloride (MOP), and the fertilizer blend comprises 15% to 40% by weight of the first fertilizer composition, 45% to 70% by weight of SSP and 10% to 30% by weight of MOP.

[0044] Aspect 18 is a fertilizer blend of any of Aspects 11 to 15, wherein the second granular fertilizer composition comprises diammonium phosphate (DAP) and potassium chloride (MOP), and the fertilizer blend comprises 15% to 40% by weight of the first fertilizer composition, 30% to 50% by weight of DAP and 20% to 45% by weight of MOP.

[0045] Aspect 19 is a fertilizer blend of any of Aspects 11 to 15, wherein the second granular fertilizer composition comprises superphosphate (TSP), and the fertilizer blend comprises 40% to 60% by weight of the first fertilizer composition and 40% to 60% by weight of TSP.

[0046] Aspect 20 is a method of fertilization, which includes applying fertilizer granules from any of Aspects 1 to 10 and / or fertilizer blends from any of Aspects 11 to 19 to soil, crops, or at least a portion of soil and crops.

[0047] In the context of this invention, fertilizer granules and / or fertilizer blend granules may also be referred to as particles, granules, fertilizer pellets, spheres or fertilizer pellets.

[0048] The term "fertilizer" is defined as a substance applied to soil or plant tissue to provide one or more plant nutrients that are important or beneficial to plant growth, and / or to act as a stimulant or enhancer to increase or promote plant growth.

[0049] The term "particle" can include solid matter. Particles can have a variety of different shapes, and non-limiting examples include spherical, disc-shaped, elliptical, rod-shaped, rectangular, or random shapes.

[0050] The term "particle" can include solid matter with a maximum size of less than 1 millimeter.

[0051] The terms “particles” or “powder” can include multiple particles.

[0052] The term "water-based" is defined as containing water or being pre-contained in water before drying.

[0053] The terms “approximately” or “about” are defined as close to as understood by one of ordinary skill in the art. In one non-limiting embodiment, the term is defined as a deviation of less than 10%, preferably less than 5%, more preferably less than 1%, and most preferably less than 0.5%.

[0054] The terms “weight%”, “volume%”, or “molar%” refer to the weight, volume, or molar percentage of a component based on the total weight of the component, the total volume of the material, or the total number of moles contained in the material. In a non-limiting example, 10 grams of component in 100 grams of material is 10% by weight of the component.

[0055] The term “substantially” is defined as including deviations within 10%, 5%, 1%, or 0.5%.

[0056] When used in the claims and / or specification, the terms “suppress” or “reduce” or “prevent” or “avoid” include any measurable reduction or complete suppression used to achieve the desired result.

[0057] As used in this specification and / or claims, the term "effective" means suitable for achieving the desired, expected, or anticipated result.

[0058] When used in conjunction with any of the terms “comprising,” “including,” “containing,” or “having” in the claims or specification, the absence of a number before an element may indicate “a,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more.”

[0059] The phrase “and / or” can include “and” or “or”. For example, A, B and / or C can include: A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B and C.

[0060] The words “contain,” “include,” “have,” or “contain” are inclusive or open-ended and do not exclude other unmentioned elements or methods or steps.

[0061] Other objects, features, and advantages of the present invention will become apparent from the following accompanying drawings, detailed description, and embodiments. However, it should be understood that while the drawings, detailed description, and embodiments illustrate specific embodiments of the invention, they are given by way of illustration only and are not intended to be limiting. Furthermore, it is anticipated that variations and modifications falling within the spirit and scope of the invention will be apparent to those skilled in the art from the detailed description herein. In other embodiments, features from a particular embodiment may be combined with features from other embodiments. For example, a feature from one embodiment may be combined with features from any other embodiment. In other embodiments, additional features may be added to the specific embodiments described herein.

[0062] Brief description of the attached figures

[0063] The advantages of the present invention will become apparent to those skilled in the art from the following detailed description and with reference to the accompanying drawings. While various modifications and alternatives to the invention are readily available, specific embodiments thereof are illustrated by way of example in the drawings. The drawings are not drawn to scale.

[0064] Figure 1: A) Cross-sectional view of fertilizer granules according to an embodiment of the present invention. B) Cross-sectional view of fertilizer granules according to another embodiment of the present invention.

[0065] Figure 2 A flowchart of a method for producing fertilizer granules according to an embodiment of the present invention is shown.

[0066] Figure 3 A flowchart is shown for a method of producing fertilizer granules according to another embodiment of the present invention.

[0067] Figure 4: A), B), C) and D) show scanning electron microscope (SEM) images of urea particles coated with example UCS.

[0068] Figure 5: A), B), C) and D) show scanning electron microscope (SEM) images of urea particles coated with example UCS.

[0069] Figure 6: Figures 4A to 4D The dark area (A), gray area (B), and bright area (C) and Figures 5A to 5D Exemplary energy-dispersive X-ray (EDX) spectra of the dark region (D), gray region (E), and bright region (F).

[0070] Figure 7: Formulation 1 of Table 1 on day 1 (A) and after 3 weeks of storage (B). Formulation 4 of Table 1 on day 1 (C) and after 3 weeks of storage (D). Formulation 7 of Table 1 on day 1 (E) and after 3 weeks of storage (F).

[0071] Detailed description of the invention

[0072] The fertilizer granules of the present invention may comprise a urea-containing core and a shell containing a urea-calcium sulfate (UCS) adduct. The fertilizer blends of the present invention may comprise a blend of core-shell fertilizer granules and at least one other fertilizer. As illustrated in a non-limiting manner in the examples, it has been found that, compared to a comparative fertilizer blend containing uncoated urea granules, the fertilizer blend containing UCS-coated urea granules and other fertilizers is relatively stable over time and does not form agglomerates or forms fewer agglomerates.

[0073] These and other non-limiting aspects of the invention are discussed in more detail in the following sections.

[0074] A. Fertilizer granules

[0075] Fertilizer granules may comprise a core and a shell forming a membrane on the core. At least any one, equal to, or between any two of the following percentages of fertilizer granules, from 90% to 99.5% by weight, or from 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, and 99.5% by weight, may consist of a core. At least any one, equal to, or between any two of the following percentages of fertilizer granules, from 0.5% to 10% by weight, or from 0.5% to 10% by weight, or from 0.5% to 10% by weight, or from 0.5% to 10% by weight, may consist of a shell. The shell can cover 5% to 100% of the outer surface of the nucleus, or at least, equal to, or between any two of the following: 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, and 100%. In some aspects, the shell can have an average thickness of 20 to 60 micrometers on the outer surface of the nucleus.

[0076] The core may contain urea. In some aspects, based on the total weight of the core, the core may contain at least, equal to, or between any two of the following: 90% to 100% by weight, or 90% to 100% by weight, or 90% to 100% by weight, or equal to any one of, or between any two of, urea. In some aspects, the core of the fertilizer granules may or may not contain other fertilizer substances besides urea. If contained, other fertilizers may be selected based on the specific needs of certain types of soil, climate, or other growing conditions to maximize the effectiveness of the fertilizer granules in promoting plant growth and increasing crop yield.

[0077] The core of fertilizer granules can have desired physical properties, such as desired levels of abrasion resistance, granule strength, granulation properties, hygroscopicity, granule shape, and particle size distribution. These are important properties of fertilizer cores.

[0078] The shell can contain UCS adducts. UCS adducts can have the chemical formula CaSO4·4CO(NH2)2. In some respects, UCS adducts can be formed from urea and gypsum using the following reaction.

[0079] Ca(H2PO4)2·H2O+4CO(NH2)2→Ca(H2PO4)2·4CO(NH2)2+H2O

[0080] In some respects, based on the total weight of the shell, the shell may contain at least any one, equal to any one, or between any two of the following UCS adducts: 20% to 100% by weight, or 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 90% by weight, 91% by weight, 92% by weight, 93% by weight, 94% by weight, 95% by weight, 96% by weight, 97% by weight, 98% by weight, 99% by weight, 99.2% by weight, 99.4% by weight, 99.5% by weight, 99.6% by weight, 99.8% by weight, 99.9% by weight, and 100% by weight. In some aspects, based on the total weight of the shell, the shell may contain 30 wt% to 90 wt%, 40 wt% to 85 wt%, 45 wt% to 80 wt%, 40 wt% to 50 wt%, 45 wt% to 55 wt%, 45 wt% to 50 wt%, 70 wt% to 80 wt%, or 75 wt% to 80 wt% of UCS adducts. In some aspects, the shell may also contain urea (e.g., present in free form, not as an adduct) and calcium sulfate (e.g., present in free form, not as an adduct). The total weight percentage of UCS adduct, urea (e.g., in free form), and calcium sulfate (e.g., in free form) in the shell can be from 95% to 100% by weight, or at least any one, equal to any one, or between any two of the following: 95% by weight, 96% by weight, 97% by weight, 98% by weight, 99% by weight, 99.2% by weight, 99.4% by weight, 99.5% by weight, 99.6% by weight, 99.8% by weight, 99.9% by weight, and 100% by weight. In some respects, based on the total weight of the shell, the shell may contain i) 18 wt% to 40 wt%, or at least any one, equal to any one, or between any two of 18 wt%, 20 wt%, 22 wt%, 24 wt%, 26 wt%, 28 wt%, 30 wt%, 32 wt%, 34 wt%, 36 wt%, 38 wt%, and 40 wt%, nitrogen (N) (e.g., from urea, existing freely and as an adduct), ii) 2 wt% to 18 wt%, or 2 wt%, 4 wt%, 6 wt%, 8 wt%, and 40 wt%. iii) at least any one of 10 wt%, 12 wt%, 14 wt%, 16 wt%, and 18 wt%, equal to any one or between any two of calcium (Ca) (e.g., from calcium sulfate, existing in free form and as an adduct) and iii) 1 wt% to 12 wt%, or at least any one of 1 wt%, 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, and 12 wt%, equal to any one or between any two of sulfur (S) (e.g., from calcium sulfate, existing in free form and as an adduct).In some respects, the weight % ratio of nitrogen (N) to calcium (Ca) in the shell can be from 15:1 to 1:1, preferably from 5:1 to 2:1, or at least any one, equal to any one, or between any two of 15:1, 14:1, 13:1, 12:1, 11:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4.5:1, 4:1, 3.5:1, 3:1, 2.5:1, 2:1, and 1:1.

[0081] The core and / or shell may optionally, independently, contain a urease inhibitor, a nitrification inhibitor, one or more minor nutrients, one or more micronutrients, or one or more binders, or any combination thereof. In some aspects, the urease inhibitor may be a triamine thiophosphate derivative, such as N-(n-butyl)thiophosphate triamine (NBPT). In some aspects, based on the total weight of the core, the core may contain 0.01% to 0.07% by weight of a urease inhibitor, such as NBPT. In some aspects, based on the total weight of the shell, the shell may contain 0.01% to 0.07% by weight of a urease inhibitor, such as NBPT. In some aspects, the nitrification inhibitor may be 3,4-dimethylpyrazole phosphate (DMPP), thiourea (TU), dicyandiamide (DCD), 2-chloro-6-(trichloromethyl)-pyridine (trichloromethylpyridine), 5-ethoxy-3-trichloromethyl-1,2,4-thiadiazole (chlorazal), 2-amino-4-chloro-6-methylpyrimidine (AM), 2-mercapto-benzothiazole (MBT) or 2-sulfathiazole (ST), or any combination thereof, preferably DCD. In some aspects, based on the total weight of the core, the core may contain 0.01% to 0.04% by weight of a nitrification inhibitor, such as DCD. In some aspects, based on the total weight of the shell, the shell may contain 0.01% to 0.04% by weight of a nitrification inhibitor, such as DCD. Micronutrients may be plant-acceptable inorganic or organometallic compounds, such as boron, copper, iron, chloride, manganese, molybdenum, nickel, or zinc. In some aspects, the core may contain 0.1% to 1.0% by weight of micronutrients based on its total weight. In some aspects, the shell may contain 0.1% to 1.0% by weight of micronutrients based on its total weight. Minor nutrients are substances that can transport calcium, magnesium, and / or sulfur to the plant. In some aspects, the core may contain 0.5% to 2.5% by weight of minor nutrients, such as calcium sulfate, lime, superphosphate, or any combination thereof, based on its total weight. In some aspects, in addition to calcium and sulfates present as calcium sulfate (free and as adducts), the shell may contain 0.5% to 2.5% by weight of other minor nutrients based on its total weight, such as lime, superphosphate, or any combination thereof.

[0082] The adhesive may be gum arabic, xanthan gum, guar gum, calcium lignosulfonate, etc. In some aspects, the shell may contain 0.001% to 0.01% by weight of adhesive based on the total weight of the shell. In some cases, the adhesive may be uniformly contained within the membrane containing the UCS adduct. In some cases, the adhesive is contained in a layer at least partially located between the core and the layer containing the UCS adduct. In some cases, the layer containing the adhesive may contain 50%, 60%, 70%, 80%, 90%, 92%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% by weight of adhesive. In some cases, the adhesive layer covers 50%, 60%, 70%, 80%, 90%, 92%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% of the core surface.

[0083] The moisture content of fertilizer granules can be less than 0.6% by weight, for example, from 0.4% to 0.6% by weight.

[0084] Based on the weight of the fertilizer granules, the total Ca content of the fertilizer granules may be 2.8 wt% or less, or 2.4 wt% or less, or 0.1 wt% to 2.2 wt%, or at most any one, equal to any one, or between any two of the following: 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.4 wt%, 1.6 wt%, 1.8 wt%, 2 wt%, and 2.2 wt%. Based on the weight of the fertilizer granules, the total nitrogen (N) content of the fertilizer granules may be 41 wt% or more, or 41 wt% to 46.2 wt%, or at least any one, equal to any one, or between any two of the following: 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 46.1 wt%, and 46.2 wt%.

[0085] In some specific aspects, the core may consist of or be substantially composed of urea and water. In some specific aspects, the shell may consist of or be substantially composed of urea, UCS adducts, calcium, sulfate, and water. In some specific aspects, fertilizer granules may consist of or be substantially composed of urea, UCS adducts, calcium, sulfate, and water.

[0086] The core and fertilizer granules can independently be any suitable shape. Non-limiting shapes include spherical, cubic, cylindrical, disc-shaped, elliptical, and rectangular. In some aspects, the core and / or fertilizer granules can be cylinders with a circular, elliptical, oval, triangular, square, rectangular, pentagonal, or hexagonal cross-section, although cylindrical cores with other cross-sectional shapes can also be prepared. In some aspects, the fertilizer granules can have dimensions such as length, width, height, and / or cross-sectional diameter of 0.5 mm to 6 mm, or at least any one of 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, and 6 mm, equal to any one, or between any two. In some specific aspects, fertilizer granules may have a substantially spherical shape with an average diameter of 0.5 mm to 5 mm, or 1 mm to 4 mm, at least any one, equal to any one, 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 aspects, the core may have dimensions such as length, width, height, and / or cross-sectional diameter of 0.5 mm to 6 mm, or at least any one, equal to any one, 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, 5 mm, 5.5 mm, and 6 mm. In some specific aspects, the nucleus may have a substantially spherical shape with an average diameter of 0.5 mm to 5 mm, or 1 mm to 4 mm, or at least any one 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, equal to any one, or between any two.

[0087] Figure 1A A cross-section of a fertilizer granule 100 according to an embodiment of the present invention is shown, comprising a core 101 and a shell 102 covering the outer surface of the core 101. The shell 102 is shown as covering the entire outer surface of the core 101, although fertilizer granules with the shell 102 covering a portion of the outer surface of the core 101 can be readily prepared. Figure 1B A cross-section of a fertilizer granule 200 according to another embodiment of the present invention is shown, comprising a core 201, an adhesive layer 202 covering the outer surface of the core 201, and a shell 203 covering the outer surface of the core coated with an adhesive (e.g., the core coated with the adhesive layer). The adhesive layer 202 is shown as covering the entire outer surface of the core 201, although it is readily possible to prepare fertilizer granules in which the adhesive layer 202 covers a portion of the outer surface of the core 201. The shell 203 is shown as covering the entire outer surface of the adhesive-coated core, although it is readily possible to prepare fertilizer granules in which the shell 203 covers a portion of the outer surface of the adhesive-coated core.

[0088] The fertilizer granules described herein may be included in compositions for application to soil.

[0089] B. Fertilizer blends

[0090] In addition to fertilizer granules, the composition may contain other fertilizer compounds, micronutrients, major nutrients, additional urea, additional nitrogen, pesticides, herbicides or fungicides, or combinations thereof. In some cases, fertilizer granules are included in the fertilizer blend. The fertilizer blend of the present invention may comprise i) 10% to 90% by weight, or at least equal to or between any two of the following: 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight and 90% by weight, and ii) 10% to 90% by weight, or at least equal to or between any two of the following: 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight and 90% by weight, of a second granular fertilizer composition. The first and second granular fertilizer compositions may each contain multiple particles; for example, the first fertilizer composition may contain multiple core-shell particles / granules, and the second fertilizer composition may contain multiple second fertilizer particles. The blend may include a mixture of multiple core-shell particles and second fertilizer particles. The fertilizer blend may be a homogeneous or non-homogeneous blend of the first and second granular fertilizer compositions.

[0091] Based on the total weight of the second granular fertilizer composition, the second granular fertilizer composition may contain 50% to 100% by weight, or at least, equal to, or between any two of the following: 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 90% by weight, 95% by weight, and 100% by weight of other plant fertilizers besides urea.

[0092] Other plant fertilizers may include phosphorus (P) sources, nitrogen (N) sources other than urea, potassium (K) sources, nitrogen and phosphorus (NP) sources, phosphorus and potassium (PK) sources, nitrogen, phosphorus and potassium (NPK) sources, micronutrients, calcium sources, sulfur sources, or any combination thereof. In some aspects, micronutrients may include plant-acceptable forms of inorganic or organometallic compounds, such as boron, copper, iron, chloride, manganese, molybdenum, nickel, and / or zinc. In some aspects, the second granular fertilizer composition may contain ammonium sulfate, monoammonium phosphate (MAP), diammonium phosphate (DAP), potassium chloride (MOP), monopotassium phosphate (MKP), triple superphosphate (TSP), phosphate rock powder, superphosphate (SSP), or any combination thereof.

[0093] In some aspects, the second granular fertilizer composition may also contain urea. In some aspects, the second granular fertilizer composition may contain two or more other plant fertilizers besides urea. In some specific aspects, the second granular fertilizer composition may contain two or more other plant fertilizers in a single particle. In some specific aspects, two or more other plant fertilizers may be contained in the second granular fertilizer composition as two or more types of particles. In some aspects, the second granule may contain diammonium phosphate (DAP), superphosphate (SSP), triple superphosphate (TSP), or potassium chloride (MOP), or combinations thereof.

[0094] In certain aspects, the second granular fertilizer composition may contain SSP, and based on the total weight of the fertilizer blend, the fertilizer blend may contain i) 40% to 60% by weight, or at least, equal to, or between any two of the following: 40% by weight, 45% by weight, 50% by weight, 55% by weight, and 60% by weight of the first granular fertilizer composition; and ii) 40% to 60% by weight, or at least, equal to, or between any two of the following: 40% by weight, 45% by weight, 50% by weight, 55% by weight, and 60% by weight of SSP.

[0095] In certain aspects, the second granular fertilizer composition may contain SSP and MOP, and based on the total weight of the fertilizer blend, the fertilizer blend may contain i) 15% to 40% by weight, or at least, equal to, or between any two of the following: 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, and 40% by weight of the first granular fertilizer composition; ii) 45% to 70% by weight, or at least, equal to, or between any two of the following: 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, and 70% by weight of SSP; and iii) 10% to 30% by weight, or at least, equal to, or between any two of the following: 10% by weight, 15% by weight, 20% by weight, 25% by weight, and 30% by weight of MOP.

[0096] In certain aspects, the second granular fertilizer composition may contain DAP and MOP, and based on the total weight of the fertilizer blend, the fertilizer blend may contain i) 15% to 40% by weight, or at least, equal to, or between any two of the following: 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, and 40% by weight of the first granular fertilizer composition; ii) 30% to 50% by weight, or at least, equal to, or between any two of the following: 30% by weight, 35% by weight, 40% by weight, 45% by weight, and 50% by weight of DAP; and iii) 20% to 45% by weight, or at least, equal to, or between any two of the following: 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, and 45% by weight of MOP.

[0097] In certain aspects, the second granular fertilizer composition may contain TSP, and based on the total weight of the fertilizer blend, the fertilizer blend may contain i) 40% to 60% by weight, or at least, equal to, or between any two of the following: 40% by weight, 45% by weight, 50% by weight, 55% by weight, and 60% by weight of the first granular fertilizer composition; and ii) 40% to 60% by weight, or at least, equal to, or between any two of the following: 40% by weight, 45% by weight, 50% by weight, 55% by weight, and 60% by weight of TSP.

[0098] The fertilizer blend particles of the present invention, such as the first granular fertilizer composition particles and / or the second granular fertilizer composition particles, may have desired physical properties, such as desired levels of abrasion resistance, particle strength, granulation, hygroscopicity, particle shape, and particle size distribution, which are important properties of fertilizers.

[0099] The fertilizer blends described herein may be included in compositions for application to soil. In addition to fertilizer blends, the composition may include other fertilizer compounds, micronutrients, major nutrients, additional urea, additional nitrogen, pesticides, herbicides or fungicides, or combinations thereof.

[0100] In some cases, according to IFDC S-104, fertilizer blends may be stable when stored for 2, 3, 4, 5, 6, 7, 8, 9, or 10 weeks, or for 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 months (e.g., with an increase in moisture content not exceeding 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 110%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, 200%, 250%, 300%, or more than 300%, or remain free-flowing, or remain free of caking, or remain non-sticky).

[0101] C. Methods for preparing fertilizer granules

[0102] Methods for preparing fertilizer granules may include providing or forming a urea-containing core, contacting and coating at least a portion of the outer surface of the core with a UCS adduct to form a shell and a core-shell-containing fertilizer granule.

[0103] Figure 2 A flowchart is shown for a method 300 for preparing fertilizer granules according to an embodiment of the present invention. (Reference) Figure 2 Urea granules 301 can be coated with a powder material containing UCS adduct 302 to form a shell on the core and fertilizer granules 303 containing the core and shell. Figure 3 A flowchart is shown for a method 400 for preparing fertilizer granules according to another embodiment of the present invention. (Reference) Figure 3 Urea granules 401 can be coated with adhesive 402 to form an adhesive-coated core 403. The adhesive-coated core 403 can be coated with a powder material containing UCS adduct 404 to form a shell on the adhesive-coated core and fertilizer granules 405 containing the core and shell.

[0104] In some aspects, the core and UCS adduct can be mixed in the presence of water to form a coating of the UCS adduct on at least a portion of the outer surface of the core, thereby forming fertilizer granules. In some aspects, a powder material containing the UCS adduct can be mixed with the core. The powder material may contain particles with an average size of 10 to 80 micrometers and may also contain urea (e.g., in free form) and calcium sulfate (e.g., in free form). The powder material can be formed by grinding and / or crushing the particles containing the UCS adduct. In some aspects, the water can be hot water with a temperature of 50°C to 80°C. In some aspects, the coating can be formed by rotating the core and powder material in a container. In some aspects, the container can be rotated at a speed of 10 to 12 RPM during the coating of the UCS powder. In some respects, 10 ml to 50 ml of water, or at least, equal to, or between any two of the following, may be added per 1000 g of the total weight of the core and powder material: 10 ml, 15 ml, 20 ml, 25 ml, 35 ml, 40 ml, 45 ml, and 50 ml of hot water. In some respects, the core and powder material may be premixed before the water is added. In some respects, optional shell components, such as urease inhibitors, nitrification inhibitors, one or more minor nutrients, one or more micronutrients, or one or more binders, or any combination thereof, may be added to the container, and the membrane on the core (e.g., the shell) may contain optional shell components. The container may be any suitable container, including but not limited to a granulator, such as a drum granulator, mixer, disc granulator, or rotary drum granulator.

[0105] In some aspects, the core can contact an adhesive to form an adhesive layer, coating at least a portion of the core's outer surface to form an adhesive-coated core. The adhesive-coated core can contact a UCS adduct, such as a powder material containing a UCS adduct, to form a coating of the UCS adduct on at least a portion of the outer surface of the adhesive-coated core, thereby forming fertilizer granules. In some aspects, the adhesive can contact the core as an adhesive solution. The adhesive solution can be an aqueous solution containing the adhesive. This aqueous solution can contain an adhesive to water weight ratio of 0.8:1 to 1:0.8, or at least any one, equal to any one, or between any two of 0.8:1, 0.9:1, 1:1, 1:0.9, and 1:0.8. In some aspects, the adhesive can be gum arabic. In some aspects, the core, the adhesive solution, and the UCS adduct can contact each other in a container. In some respects, optional shell components, such as urease inhibitors, nitrification inhibitors, one or more minor nutrients, one or more micronutrients, or one or more binders, or any combination thereof, may be added to the container, and the core, such as the membrane (e.g., shell) on a binder-coated core, may contain the optional shell components. The container can be any suitable container, including but not limited to a granulator, such as a drum granulator, mixer, disc granulator, or rotary drum granulator.

[0106] In some respects, the nucleus can be formed as a sphere or the nucleus can be formed by granulation, compaction and / or granulation of a composition containing urea and optionally a urease inhibitor, a nitrification inhibitor, one or more minor nutrients or one or more micronutrients, or combinations thereof.

[0107] D. Methods for preparing fertilizer blends

[0108] The fertilizer blend of the present invention can be formed by blending a first granular fertilizer composition and a second granular fertilizer composition in a weight ratio of 1:9 to 9:1, or at least any one, equal to any one, or between any two of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1. The first granular fertilizer composition and the second granular fertilizer composition can be blended by methods known in the art. For example, the first granular fertilizer composition and the second granular fertilizer composition can be blended in granular form by dry mixing. In some aspects, the granular first granular fertilizer composition can be contacted and mixed with the granular second granular fertilizer composition to form a fertilizer blend. The first granular fertilizer composition and the second granular fertilizer composition can be blended, for example, by mixing, using equipment known in the art such as a mixer.

[0109] E. Application methods of fertilizer granules and / or blends

[0110] The fertilizer granules, compositions containing fertilizer granules, and fertilizer blends containing fertilizer granules of the present invention can be used in methods for increasing the amount of nitrogen and optionally other plant nutrients in soil, as well as methods for promoting plant growth. These methods may include applying an effective amount of the composition and / or blend containing the fertilizer granules of the present invention to the soil. These methods may include increasing the growth and yield of crops, trees, ornamental plants, etc., such as palm trees, coconuts, rice, wheat, corn, barley, oats, and / or soybeans. These methods may include applying the fertilizer blends of the present invention to at least one of soil, organisms, liquid carriers, liquid solvents, etc.

[0111] Non-limiting examples of plants that can benefit from the fertilizer of this invention include vines, trees, shrubs, straw plants, ferns, etc. Plants may include orchard crops, vines, ornamental plants, food crops, timber, and harvestable plants. Plants may include gymnosperms, angiosperms, and / or ferns. Gymnosperms may include plants from the Araucariaceae, Cupressaceae, Pinaceae, Podocarpaceae, Pinaceae, Taxaceae, Cycadaceae, and Ginkgoaceae families. Angiosperms can include those from the following families: Aceraceae, Agavaceae, Anacardiaceae, Annonaceae, Apocynaceae, Aquifoliaceae, Araliaceae, Arecaceae, Asparagaceae, Asteraceae, Berberidaceae, Betulaceae, Bignoniaceae, Bombacaceae, Boraginaceae, Burseraceae, Buxusaceae, Lauraceae, Cannabaceae, Caprifoliaceae, Caricaceae, Casuarinaceae, Celastraceae, Cercidiaceae, Casuarina, Ostreaceae, Hypericaceae, Combretaceae, Cornaceae, Tanneraceae, Sorbusaceae, Ebenaceae, Elaeagnaceae, Ericaceae, Euphorbiaceae, Fabaceae, Fagaceae, Curcumaceae, Hamamelidaceae, Aesculentaceae, Illicaceae, Juglandaceae, Lauraceae, Lepidaceae, Lythraceae, Magnoliaceae, Malvaceae, and Malva. Plants of the following families: Melastomataceae, Meliaceae, Moraceae, Moringaceae, Mandinaceae, Burseraceae, Myricaceae, Myrsinaceae, Myrtaceae, Quercus acutissima, Nyctaginaceae, Nelumbo nuciferaceae, Oleaceae, Oxalisceae, Pandanaceae, Papaveraceae, Phyllanthaceae, Pittosporum family, Platanaceae, Poaceae, Polygonaceae, Proteaceae, Punicaceae, Rhamnaceae, Mangrove family, Rosaceae, Rubiaceae, Rutaceae, Salicaceae, Sapindaceae, Gleditsiaceae, Simaroubaceae, Solanaceae, Sterculiaceae, Strigaceae, Strigaceae, Styraxaceae, Styraxaceae, Styraxaceae, Styraxaceae, Styraxaceae, Sapindaceae, Tamarixaceae, Theaceae, Erythrinaceae, Thymelaeaceae, Tiliaceae, Ulmaceae, Verbenaceae and / or Vitaceae.

[0112] The effectiveness of the composition containing the fertilizer granules of the present invention can be determined by measuring the amount of nitrogen and optionally other nutrients in the soil at different times after the fertilizer composition has been applied to the soil. It should be understood that different soils have different characteristics, which can affect the stability of nitrogen in the soil. The effectiveness of the fertilizer composition can also be directly compared with other fertilizer compositions (e.g., those containing uncoated urea granules rather than UCS-coated urea granules) by conducting side-by-side comparisons under the same conditions in the same soil. Example

[0113] This invention will be described in more detail through specific embodiments. The embodiments provided are for illustrative purposes only and are not intended to limit the invention in any way. Those skilled in the art will readily recognize various non-critical parameters that can be modified or changed to produce substantially the same results.

[0114] Example 1

[0115] Urea fertilizer granules containing UCS coating

[0116] UCS-coated urea was prepared by disc granulation. 800g of urea granules were added to a disc granulator. 200g of powder material (10 to 80 microns) containing UCS adducts was added to the granulator. 20 to 30 ml of 80°C water was sprayed into the granulator. The urea and powder material in the granulator were rotated and mixed in the presence of water to form fertilizer granules containing UCS-coated urea, wherein the coating accounted for 2% to 4% of the total weight of the UCS-coated urea. Two parallel experiments were conducted. In the first experiment, the powder material used for coating (labeled UCS-27) had 27.6% N, 9.13% Ca, and 6.86% S, and the UCS adduct content was 75.62% by weight. In the second experiment, the powder material used for coating (labeled UCS-33) had 34% N by weight, 5.22% Ca by weight, and 6.08% S by weight, and the UCS adduct content was 48% by weight. Figures 4A to 4D The image shows scanning electron microscope (SEM) images of four UCS-coated urea particles of UCS-27 obtained in Example 1, particles 1 to 4. Figures 5A to 5D SEM images of particles 1 through 4 at higher magnification are shown. Figures 4A to 4D and Figures 5A to 5D In the diagram, the dark areas are composed of urea (marked by arrow a), the gray areas are composed of urea-calcium sulfate adducts (marked by arrow b), and the white / bright areas are composed of calcium sulfate (marked by arrow c). Figure 6A , Figure 6B and Figure 6C They are shown respectively as follows Figures 4A to 4D The energy dispersive X-ray (EDX) spectra of the dark region (A), gray region (B), and bright region (C) are shown. Figure 6D , Figure 6E and Figure 6F They are shown respectively as follows Figures 5A to 5D The EDX spectra of the dark region (A), gray region (B), and bright region (C) are shown.

[0117] Example 2

[0118] Fertilizer granules containing binders and UCS-coated urea

[0119] Urea granules are added to a coating drum. A 1:1 aqueous solution containing gum arabic is sprayed onto the urea granules in the drum, forming an adhesive coating, such as gum arabic, on the urea granules, thus forming adhesive-coated urea. A powder material containing a UCS adduct is added to the coating drum and brought into contact with the adhesive-coated urea granules, forming a UCS coating layer on the granules. The amount of powder material used for coating is varied to obtain fertilizer granules containing 2%, 3%, and 4% coating based on the weight of the fertilizer granules.

[0120] Example 3

[0121] Fertilizer blends containing UCS-coated urea and a second fertilizer composition

[0122] The UCS-coated urea granules obtained from Experiments 1 and 2 of Example 1 were blended with other fertilizer compositions. The compositions of the blends (Formulations 6 to 11) are listed in Table 1. The stability of the blends was tested using the IFDC protocol (IFDC S-104 "Chemical Compatibility of Blends"). For comparison, blends containing uncoated urea were also prepared (Formulations 1 to 5, Table 1).

[0123] In short, each blend was prepared in 200 ml glass vials. Approximately two-thirds of the vial was filled with each blend. Freshly prepared blend samples were tightly capped in the vials and placed in an oven at 30°C for at least 30 days. The blends were examined daily, and any wetting, clumping, disintegration, or gas escape was recorded. The blends were rated after three weeks of storage based on the following compatibility levels.

[0124] D = Dry, free-flowing - (compatible) passage;

[0125] W1 = Moisture patch, but can be passed through by - (in most cases compatible);

[0126] W2 = moist and slightly sticky, but may be usable (mostly compatible) and passable;

[0127] W3 = Soaked and sticky, unsuitable for use - (incompatible in most cases) Failed;

[0128] W4 = Very wet, not suitable for use - (Incompatible) Failed;

[0129] H = Hardened clumps together, unsuitable for use - (incompatible) failure.

[0130] Table 1

[0131]

[0132] The compatibility grades of the blends are shown in Table 1. As can be seen from Table 1, after 3 weeks of storage, the blends containing urea coated with UCS flowed freely and showed little or no agglomeration, while the blends containing uncoated urea formed sticky substances and / or hard lumps. Figure 7A and Figure 7B Formulation 1, containing uncoated urea and SSP, is shown on day 1 and after 3 weeks of storage. Figure 7C and Figure 7D The formulation 4, containing uncoated urea and TSP, was shown on day 1 and after 3 weeks of storage. Figure 7E and Figure 7F The results show formulation 7 containing UCS-coated urea and SSP during day 1 and week 3 of storage. From Figures 7A to 7F It can be seen that while formulation 7 remained dry and free-flowing after 3 weeks of storage, formulations 1 and 4 became viscous substances after 3 weeks of storage. Therefore, Table 1 and Figures 7A to 7F The results show that urea coated with UCS adduct stabilizes blends of urea with other fertilizer compositions.

Claims

1. A fertilizer granule comprising: a core comprising at least 90 wt% urea; and a shell comprising a urea calcium sulfate (UCS) adduct, wherein the shell covers at least a portion of an outer surface of the core, and wherein the fertilizer granule has a calcium (Ca) content of 2.8 wt% or less, and the fertilizer granule has a nitrogen (N) content of 41 wt% or more.

2. The fertilizer granule of claim 1, wherein the shell comprises 20 wt% to 100 wt% of the UCS adduct, based on the total weight of the shell.

3. The fertilizer granule of any one of claims 1 to 2, wherein the core further comprises a urease inhibitor, a nitrification inhibitor, one or more secondary nutrients, or one or more micronutrient nutrients, or any combination thereof.

4. The fertilizer granule of any one of claims 1 to 2, wherein the shell further comprises urea and calcium sulfate.

5. The fertilizer granule of any one of claims 1 to 2, wherein at least 95 wt% of the shell consists of the UCS adduct, urea, and calcium sulfate.

6. The fertilizer granule of any one of claims 1 to 2, wherein the wt% ratio of N to Ca in the shell is 15: 1 to 1 : 1, and / or the Ca content of the fertilizer granule is 1.8 wt% or less.

7. The fertilizer granule of any one of claims 1 to 2, wherein the UCS adduct has a chemical formula of CaS04.4CO(NH2)2.

8. The fertilizer granule of any one of claims 1 to 2, wherein the shell further comprises a urease inhibitor, a nitrification inhibitor, one or more secondary nutrients, one or more micronutrient nutrients, or one or more binders, or any combination thereof.

9. The fertilizer granule of any one of claims 1 to 2, further comprising a binding layer, wherein at least a portion of the binding layer is positioned between the core and the shell.

10. The fertilizer granule of any one of claims 1 to 2, wherein the weight ratio of the core to the shell is 90: 10 to 99.5:0.

5.

11. A fertilizer blend comprising: 10 wt% to 90 wt% of a first particulate fertilizer composition, the first particulate fertilizer composition comprising the fertilizer granule of any one of claims 1 to 10; and 10 wt% to 90 wt% of a second particulate fertilizer composition, wherein the first particulate fertilizer composition is different from the second particulate fertilizer composition, wherein the second particulate fertilizer composition is blended with the first particulate fertilizer composition.

12. The fertilizer blend of claim 11, wherein the second particulate fertilizer composition comprises a phosphorus fertilizer.

13. The fertilizer blend of any one of claims 11 to 12, wherein the second particulate fertilizer composition comprises a potassium fertilizer.

14. The fertilizer blend of any one of claims 11 to 12, wherein the second particulate fertilizer composition comprises diammonium phosphate (DAP), single superphosphate (SSP), triple superphosphate (TSP), or muriate of potash (MOP), or any combination thereof.

15. The fertilizer blend of any one of claims 11-12, wherein the second particulate fertilizer composition comprises single superphosphate (SSP), and the fertilizer blend comprises 40-60 wt% of the first fertilizer composition and 40-60 wt% of the SSP.

16. The fertilizer blend of any one of claims 11-12, wherein the second particulate fertilizer composition comprises single superphosphate (SSP) and muriate of potash (MOP), and the fertilizer blend comprises 15-40 wt% of the first fertilizer composition, 45-70 wt% of the SSP, and 10-30 wt% of the MOP.

17. The fertilizer blend of any one of claims 11-12, wherein the second particulate fertilizer composition comprises diammonium phosphate (DAP) and muriate of potash (MOP), and the fertilizer blend comprises 15-40 wt% of the first fertilizer composition, 30-50 wt% of the DAP, and 20-45 wt% of the MOP.

18. The fertilizer blend of any one of claims 11-12, wherein the second particulate fertilizer composition comprises triple superphosphate (TSP), and the fertilizer blend comprises 40-60 wt% of the first fertilizer composition and 40-60 wt% of the TSP.

19. A method of fertilizing, the method comprising applying the fertilizer granule of any one of claims 1-10 to at least a portion of a soil, a crop, or both.

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