A coated urea fertilizer and a method for the production thereof

Abstract

There is provided a coated urea granule comprising a core of urea and at least one coating layer comprising a mixture of rosin and a lubricant.

Description

[0001] A COATED UREA FERTILIZER AND A METHOD FOR THE PRODUCTION THEREOF

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of agriculture, specifically to coated urea fertilizers. More particularly, it concerns a method and composition for producing coated urea fertilizers with enhanced moisture resistance and controlled nutrient release.

[0004] BACKGROUND OF THE INVENTION

[0005] Urea is a widely used nitrogenous fertilizer in the agricultural sector due to its high nitrogen content, cost-effectiveness, and ease of application. It plays a crucial role in promoting plant growth and increasing crop yields. However, the use of urea as a fertilizer presents several challenges that need to be addressed.

[0006] One of the primary challenges associated with urea fertilizers is their hygroscopic nature. This characteristic causes urea granules to absorb moisture from the environment, leading to clumping and degradation of the granules. As a result, the fertilizer loses its nutrient value and becomes less effective for agricultural applications. Furthermore, this moisture absorption can cause storage and handling issues, making it difficult to maintain the quality and effectiveness of urea-based fertilizers.

[0007] Another challenge with urea fertilizers is the release of ammonia into the atmosphere. After applying urea on a soil, it reacts with water under the presence of urease enzyme, it undergoes hydrolysis, converting it into ammonia and carbon dioxide. The release of ammonia contributes to environmental pollution, including greenhouse gas emissions and eutrophication of water bodies. Moreover, the loss of ammonia reduces the efficiency of urea as a nitrogen source for plants, necessitating higher application rates to achieve the desired crop yield.

[0008] Various methods and compositions have been developed to address these challenges by coating urea granules with different materials. These coatings aim to reduce moisture absorption, control the release of nitrogen, and improve the storage and handling properties of urea fertilizers. However, many existing coating technologies require high amounts of coating materials, which can increase production costs and contribute to environmental concerns. Furthermore, some of these coating methods may not provide adequate protection against moisture or controlled nutrient release, limiting their effectiveness in various agricultural applications.

[0009] BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure l is a graph depicting the volatilization of NH3, according to some demonstrative embodiments of the present invention.

[0011] Figure 2 is a graph depicting the volatilization of N2O, according to some demonstrative embodiments of the present invention.

[0012] Figure 3 is a graph depicting CO2 emissions, according to some demonstrative embodiments of the present invention.

[0013] Figure 4 is a graph depicting the volatilization of NH3, according to some demonstrative embodiments of the present invention.

[0014] Figure 5 shows 3 graphs depicting CO2 emissions, %N volatilization as N2O and %N volatilization as NH3, according to some demonstrative embodiments of the present invention.

[0015] SUMMARY OF THE INVENTION

[0016] According to some embodiments, coated urea granule comprising a core of urea and at least one coating layer comprising a mixture of rosin and a lubricant.

[0017] According to some embodiments, the rosin may be selected from the group including Gum Rosin, Hydrogenated rosin, Tall oil rosin, Wood rosin, Maleic anhydride-modified rosin, Polymerized rosin, Rosin esters or similar solid forms of resin.

[0018] According to some embodiments, the rosin may preferably be Gum Rosin.

[0019] According to some embodiments, the lubricant may be selected from the group including Paraffin wax, Beeswax, Carnauba wax, Candelilla wax, Microcrystalline wax, Soy wax, Polyethylene, Polypropylene, Petroleum j elly, Mineral oil, Palm oil, Castor oil, Lanolin, and Stearic acid, black soldier fly (BSF) wax and the like. According to some embodiments, the ratio of rosin to lubricant in the coating may range from 10:90 to 90: 10, preferably 70:30.

[0020] According to some embodiments, the granule may further include a fertilizer powder in the coating selected from the group consisting of Urea, Polyhalite, Ammonium nitrate, Diammonium phosphate (DAP), Monoammonium phosphate (MAP), Potassium chloride (Muriate of Potash), Superphosphate, Ammonium sulfate, Calcium ammonium nitrate (CAN), Ammonium phosphates, Triple superphosphate (TSP), Potassium nitrate, Potassium sulfate, Sodium nitrate, Nitrogen-phosphorus-potassium (NPK) blends, Ammonium chloride, Calcium nitrate, Ammonium polyphosphate, Magnesium sulfate (Epsom salt), Micronutrient fertilizers (e g., zinc sulfate, copper sulfate) or combinations thereof.

[0021] According to some embodiments, preferably, the fertilizer powder in the coating may be selected from the group including Urea, Polyhalite, Ammonium nitrate, Diammonium phosphate (DAP), Monoammonium phosphate (MAP), Potassium chloride (Muriate of Potash), Superphosphate, Ammonium sulfate, Calcium ammonium nitrate (CAN), Ammonium phosphates, Triple superphosphate (TSP), Potassium nitrate, Potassium sulfate, Sodium nitrate, Nitrogen-phosphorus-potassium (NPK) blends, Ammonium chloride, Calcium nitrate, Ammonium polyphosphate, Magnesium sulfate (Epsom salt), Micronutrient fertilizers (e g., zinc sulfate, copper sulfate) or combinations thereof According to some embodiments, there is provided herein a process for the production of a fertilizer granule comprising: Preparing a core using granular urea; Warming the granular urea to 70-120°C; Adding a combination of rosin and lubricant to yield coated granules, wherein the rosin and lubricant combination becomes liquid when exposed to the granular urea at 70-120°C and coats the core; Adding a fertilizer powder to the coated granules.

[0022] According to some embodiments, the fertilizer powder may be selected from the group including Urea, Polyhalite, Ammonium nitrate, Diammonium phosphate (DAP), Monoammonium phosphate (MAP), Potassium chloride (Muriate of Potash), Superphosphate, Ammonium sulfate, Calcium ammonium nitrate (CAN), Ammonium phosphates, Triple superphosphate (TSP), Potassium nitrate, Potassium sulfate, Sodium nitrate, Nitrogen-phosphorus-potassium (NPK) blends, Ammonium chloride, Calcium nitrate, Ammonium polyphosphate, Magnesium sulfate (Epsom salt), Micronutrient fertilizers (e.g., zinc sulfate, copper sulfate) or combinations thereof.

[0023] According to some embodiments, the ratio of the rosin to lubricant may be 70:30 and the fertilizer powder may be applied at a concentration of 5-20% w / w of the total granule weight, resulting in enhanced resistance to moisture and controlled nutrient release.

[0024] According to some embodiments, the coated granules may further be subjected to an additional coating step, adding another layer of material to improve resistance to environmental degradation or to modify the release rate of nutrients.

[0025] DETAILED DESCRIPTION OF THE INVENTION

[0026] According to some demonstrative embodiments, there is provided herein a coated urea granule, comprising a core including urea and at least one coating layer comprising a mixture of rosin and a lubricant.

[0027] According to some demonstrative embodiments the coated urea granule of the present invention comprises a urea core that may be uniformly encapsulated by at least one coating layer. The coating layer may be formed from a homogeneous mixture of rosin and a lubricant. According to some demonstrative embodiments, the weight ratio of rosin to lubricant may range from 10:90 to 90:10, with preferred ratios being 20:80 to 80:20, and most preferably 70:30.

[0028] According to some demonstrative embodiments, the coating layer is designed to form a continuous fdm around the urea core, providing an effective barrier against moisture and controlling the release of nutrients. The ability of the rosin to form a continuous fdm when combined with wax lubricants is crucial to the invention, as it ensures the performance and stability of the coated urea fertilizer.

[0029] According to some embodiments, the rosin may include any suitable solid form of resin selected from the group including: Gum Rosin, Hydrogenated rosin, Tall oil rosin, Wood rosin, Maleic anhydride-modified rosin, Polymerized rosin, Rosin esters and the like.

[0030] According to some embodiments, the rosin may present unique and surprising compatibility with wax lubricants. According to some embodiments, the rosin may be compatible with various wax lubricants, allowing for a wide range of mixtures and compositions to be formulated depending on the desired coating properties, cost considerations, and environmental impact.

[0031] For example, the rosin may form a continuous film when combined with wax lubricants, which is crucial in providing an effective barrier against moisture and ensuring controlled nutrient release. The film-forming ability of rosin contributes to the overall performance and stability of the coated urea fertilizer.

[0032] According to some embodiments, the rosin may preferably be Gum Rosin.

[0033] According to some embodiments, the unique combination of gum rosin and a lubricant, specifically in the coating of urea, and more specifically, in the coating of a melt and ground urea composition, allows for superior properties of the resulting granule and advanced beneficial characteristics.

[0034] For example, according to some embodiments, Gum rosin may exhibit strong adhesive properties, which help create a robust and stable bond between the urea granules and the coating mixture. According to some embodiments, this may ensure the proper formation of a protective barrier around the granules, enhancing moisture resistance and storage stability

[0035] According to some embodiments, Gum rosin is hydrophobic, meaning it repels water, and this may be essential in creating a moisture-resistant coating for the urea granules, preventing the absorption of water and reducing the risk of premature nutrient release, clumping, or degradation during storage and transportation.

[0036] According to some embodiments, gum rosin may be preferable since it comes from a natural origin. According to some embodiments gum rosin may be derived from pine tree resin, making it a renewable and environmentally friendly raw material.

[0037] In certain embodiments, the coating may be applied in multiple layers, with each layer potentially incorporating different additives or compositions to further enhance the granule’s performance. For instance, an outermost layer may include a UV protective agent to prevent degradation from sunlight exposure.

[0038] According to some embodiments, the unique and surprising combination of adhesion, hydrophobicity, compatibility with wax lubricants, film-forming ability, natural origin, and cost-effectiveness make gum rosin a preferable component in the invention specifically related to coating melted and ground urea combination fertilizers. According to some embodiments, the lubricant(s) of the present invention may be selected from the group including: Paraffin wax, Beeswax, Carnauba wax, Candelilla wax, Microcrystalline wax, Soy wax, Polyethylene, Polypropylene, Petroleum jelly, Mineral oil, Palm oil, Castor oil, Lanolin and Stearic acid.

[0039] According to some demonstrative embodiments, the ratios of rosin to lubricant in the coating may range from 10:90 to 90: 10, preferably 20:80 to 80:20, most preferably 70:30.

[0040] According to some demonstrative embodiments, the specific ratio of 60:40 to 80:20, and most preferably 70:30 has surprisingly been shown to be the optimal point between the hardness of the rosin and the elasticity of the lubricant. Adding more rosin beyond this ratio may cause the coating to have excessive cracks and be more fragile. On the other hand, adding more lubricant beyond the beforementioned ratio may cause stickiness of the coating and caking.

[0041] According to some demonstrative embodiments, the coating comprising the combination of rosin and lubricant may achieve efficient result whilst being relatively thin, e g., in a concentration of between 5-7% w / w of the total granule weight.

[0042] Whilst ordinary coating layers having the functionality of the coating of the present invention are usually in a concentration of 20% w / w or more of the total weight of the granule, the coating of the present invention may be in a concentration of no more than 20% w / w, preferably 5-7% w / w.

[0043] According to some demonstrative embodiments, the coating may be in a concentration of between 2-20% w / w of total granule weight, preferably, 5-7% w / w, due to an addition of a fertilizer powder.

[0044] According to some embodiments, the particle size of the fertilizer powder may preferably be below 500 microns.

[0045] According to some embodiments, the powder may be added in a ratio of 1 : 1 powder to coating. Alternatively, the powder may be added in a concentration of 5-20% w / w of the core urea.

[0046] According to some embodiments, the addition of fertilizer powder to the coating, such as urea powder, may enhance the performance of the granule by preventing aggregation and improving rheology. Surprisingly, the inclusion of the fertilizer powder not only maintains the integrity of the coating but also contributes to the formation of a strong, water-repellent barrier.

[0047] According to some embodiments, the urea core may also be supplemented with additional fertilizers, such as micronutrient blends or slow-release additives, to create a synergistic effect when the granule is applied to the soil. These additives may be chosen based on the specific agricultural needs and soil conditions.

[0048] According to some embodiments, the fertilizer powder may be selected from the group including Urea, Polyhalite, Ammonium nitrate, Diammonium phosphate (DAP), Monoammonium phosphate (MAP), Potassium chloride (Muriate of Potash), Superphosphate, Ammonium sulfate, Calcium ammonium nitrate (CAN), Ammonium phosphates, Triple superphosphate (TSP), Potassium nitrate, Potassium sulfate, Sodium nitrate, Nitrogen-phosphorus-potassium (NPK) blends, Ammonium chloride, Calcium nitrate, Ammonium polyphosphate, Magnesium sulfate (Epsom salt), Micronutrient fertilizers (e.g., zinc sulfate, copper sulfate) or combinations thereof.

[0049] According to some embodiments, the fertilizer powder may preferably be urea powder.

[0050] According to some embodiments, the addition of the fertilizer powder, e.g., urea powder, to the coating prevents aggregation of the granules to one another.

[0051] According to some embodiments, urea granules coated by a rosin-wax combination tend to adhere to one another due to the oily nature of the coating, using the addition of the fertilizer powder as per the present invention allows for preventing such an adhesion and for a proper rheology.

[0052] According to some embodiments, the addition of the fertilizer powder provides a surprising result, as one would expect that such an addition would harm the coating as the incorporation into the coating might cause cracks and / or deformation in the coating layer.

[0053] However, it was surprisingly found that the addition of the fertilizer powder into the coating creates a strong uniform, water repelling coating, whilst diminishing the adherence and aggregation between the coated granules.

[0054] According to some embodiments, the urea core of the present invention may include one or more additional fertilizers, e.g., to provide a synergistic effect when the urea core is exposed to the ground, for example. After dissolvement of the coating. According to some embodiments, the one or more additional fertilizers may be selected from the group including Urea, Polyhalite, Ammonium nitrate, Diammonium phosphate (DAP), Monoammonium phosphate (MAP), Potassium chloride (Muriate of Potash), Superphosphate, Ammonium sulfate, Calcium ammonium nitrate (CAN), Ammonium phosphates, Triple superphosphate (TSP), Potassium nitrate, Potassium sulfate, Sodium nitrate, Nitrogen-phosphorus-potassium (NPK) blends, Ammonium chloride, Calcium nitrate, Ammonium polyphosphate, Magnesium sulfate (Epsom salt), Micronutrient fertilizers (e g., zinc sulfate, copper sulfate) or combinations thereof.

[0055] According to some demonstrative embodiments, there is provided herein a process for the production of a fertilizer granule, wherein the process includes:

[0056] Screening granular urea via a l-4mm sieve (also referred to herein as core urea);

[0057] Warming the granular urea to 70-120°C;

[0058] Mixing Rosin and a lubricant to provide a Rosin / lubricant mixture;

[0059] Warming the rosin / lubricant mixture to a temperature of 80-120°C until the mixture is melted;

[0060] Adding the melted rosin / lubricant mixture to the granular urea to yield a coated granules;

[0061] Adding a fertilizer powder to the coated granules.

[0062] According to some demonstrative embodiments, the core urea may include additional compounds in addition to urea selected from the group including Polyhalite, Ammonium nitrate, Diammonium phosphate (DAP), Monoammonium phosphate (MAP), Potassium chloride (Muriate of Potash), Superphosphate, Ammonium sulfate, Calcium ammonium nitrate (CAN), Ammonium phosphates, Triple superphosphate (TSP), Potassium nitrate, Potassium sulfate, Sodium nitrate, Nitrogen-phosphorus- potassium (NPK) blends, Ammonium chloride, Calcium nitrate, Ammonium polyphosphate, Magnesium sulfate (Epsom salt), Micronutrient fertilizers (e.g., zinc sulfate, copper sulfate) or combinations thereof.

[0063] In some embodiments of the present invention, the granular urea may be screened through a sieve with a different range. For instance, a 2-3mm sieve may be employed to achieve a more uniform or desirable granule size. According to these embodiments, using a uniform size of granules may positively affect the release rate of the urea. In some embodiments of the present invention, the warming temperature for the granular urea may be adjusted. For example, the urea may be heated to a range of 80- 100°C, the specific temperature being contingent on the type of urea utilized or the desired characteristics of the final product.

[0064] In alternative embodiments, additives apart from rosin and lubricant might be amalgamated to form a coating mixture. This could encompass other substances known to enhance the attributes of the fertilizer granules, such as binding agents or colorants.

[0065] In other embodiments, the coated granules may be subjected to multiple layers of different materials. This could involve extra layers of the rosin / lubricant mixture, or layers of different substances designed to enhance the properties of the fertilizer granules further.

[0066] According to some embodiments, the invention may incorporate different types of fertilizer powders added to the coated granules. This flexibility allows for the creation of fertilizer granules with distinct nutrient profiles or release characteristics, tailored to specific agricultural needs.

[0067] In certain embodiments disclosed herein, a method for manufacturing fertilizer granules is described. The method comprises the following steps:

[0068] Creating a core by utilizing granular urea;

[0069] Heating the granular urea to 80°C;

[0070] Introducing a mixture of Rosin and lubricant while continuously stirring to produce a coating on the granules. According to some embodiments, this combination of rosin and lubricant transforms into a liquid state upon contact with the granular urea at 80°C, effectively coating the core;

[0071] Incorporating urea powder onto the coated granules to yield fertilizer granules; and

[0072] Wherein the mixture of Rosin and lubricant is in a concentration of between 2- 20% w / w, preferably 5-7% w / w, from the total weight of the granule.

[0073] According to some embodiments, the process may include adding ground urea (urea powder) to the coating mixture in a ratio of about 5-20% by weight of the total urea to prevent stickiness of the mass and enable wider control of the coating quantities. According to some other embodiments, the powder may be added in a ratio of 1 : 1 powder to coating.

[0074] According to some embodiments, the process may include stirring the mixture of Rosin and lubricant with the granular urea for a duration of about 3 minutes, or until the urea granules are fully dispersed, resulting in the separation of granules and the formation of a stable coating, wherein the amount of coating applied to the urea granules may vary depending on the desired resistance to moisture, and good results can be expected with a coating amount between 5% to 20% of the overall weight of the granule;

[0075] According to some embodiments, there is provided herein a process for obtaining a coated urea fertilizer product that exhibits excellent protection against moisture, improved storage stability, and controlled nutrient release when used as a fertilizer.

[0076] According to some embodiments, and as demonstrated in the examples, laboratory results demonstrate a reduction in ammonia release up to 10 times better than that of a blank sample.

[0077] According to some demonstrative embodiments, other ground materials, such as fillers or additional nutrients, can be incorporated into the coating mixture to further enhance the properties of the final product. The choice of additional materials can depend on factors such as the intended use of the urea fertilizer and the specific requirements of the agricultural application. Ground material can consist of Polyhalite, Ammonium nitrate, Diammonium phosphate (DAP), Monoammonium phosphate (MAP), Potassium chloride (Muriate of Potash), Superphosphate, Ammonium sulfate, Calcium ammonium nitrate (CAN), Ammonium phosphates, Triple superphosphate (TSP), Potassium nitrate, Potassium sulfate, Sodium nitrate, Nitrogen-phosphorus- potassium (NPK) blends, Ammonium chloride, Calcium nitrate, Ammonium polyphosphate, Magnesium sulfate (Epsom salt), Micronutrient fertilizers (e.g., zinc sulfate, copper sulfate) or combinations thereof.

[0078] According to some demonstrative embodiments, the adhesive coating can be used as an adhesion promoter for incorporating other fertilizers, such as polyhalite, into the coated urea granules. This versatile approach allows for the creation of customized, multi-nutrient fertilizers with tailored release profiles and improved agronomic properties. According to some demonstrative embodiments, there is provided herein a process for producing coated urea granules. The process may include the following steps:

[0079] Screening granular urea to a size of 1-4 mm.

[0080] Heating the granular urea to a temperature ranging from 70°C to 120°C.

[0081] Mixing rosin and a lubricant to form a homogeneous mixture, which is then heated to a temperature of 80°C to 120°C until fully melted.

[0082] Coating the heated urea granules with the melted rosin-lubricant mixture.

[0083] Optionally adding a fertilizer powder to the coated granules to complete the process.

[0084] The process may include additional steps such as cooling the coated granules under controlled conditions to ensure uniform coating thickness and curing to enhance the coating's durability and moisture resistance.

[0085] According to some embodiments, the fertilizer powder may be added in a ratio of 1 : 1 powder to coating. Alternatively, the amount of powder may be calculated to be in a 5-20% w / w of the amount of urea in the core.

[0086] In alternative embodiments, the process may be modified to include the application of multiple coating layers with varying compositions, drying steps between layers, or post-processing treatments such as surface smoothing or polishing to achieve the desired final product characteristics.

[0087] According to some embodiments, the coating layer comprising a mixture of rosin and lubricant is specifically designed to provide superior moisture resistance. By forming a continuous hydrophobic film around the urea core, the coating prevents the absorption of ambient moisture, thereby significantly reducing clumping and degradation of the granules during storage and handling. This hydrophobic barrier ensures that the granules maintain their structural integrity and nutrient content over extended periods, even in high-humidity environments. As a result, the present invention offers a reliable solution for maintaining fertilizer efficacy in challenging agricultural conditions.

[0088] According to some embodiments, the coated urea granules of the present invention exhibit a substantial reduction in nitrogen volatilization when compared to uncoated urea. The coating layer acts as a controlled-release barrier, allowing for a gradual and sustained release of nitrogen into the soil, thereby reducing the loss of nitrogen to the atmosphere in the form of ammonia (Ni b) and nitrous oxide (N2O). Laboratory testing has demonstrated that the coated granules can reduce ammonia volatilization by up to 90%, while nitrous oxide emissions are reduced by approximately 85%, making the present invention a more environmentally friendly option for nitrogenous fertilization.

[0089] According to some embodiments, the coating process can be further customized by applying multiple layers with varying compositions. For example, an outer layer may be formulated to include UV-protective agents that shield the granules from sunlight- induced degradation, thereby preserving the integrity of the inner coating and extending the shelflife of the fertilizer. Additional layers can also incorporate slow-release additives or micronutrients, allowing the granules to be tailored to specific soil conditions or crop requirements. This multilayer approach offers a versatile and adaptable solution for diverse agricultural applications.

[0090] According to some embodiments, the coating composition is optimized to maintain its effectiveness while minimizing the overall coating weight. The present invention achieves this balance by utilizing a coating concentration of only 5-7% w / w of the total granule weight, which is significantly less than the typical 20% w / w found in conventional coated fertilizers. Despite the reduced coating thickness, the formulation ensures robust moisture resistance and controlled nutrient release, thereby offering an efficient and cost-effective solution for agricultural fertilization.

[0091] According to some embodiments, the addition of a fertilizer powder to the coating, such as urea powder, not only improves the handling properties of the granules but also enhances the performance of the fertilizer. The inclusion of the powder prevents the granules from sticking together, ensuring uniform dispersion during application. Additionally, the powder enhances the water-repellent properties of the coating, further protecting the urea core from moisture ingress and ensuring the controlled release of nitrogen over time. This innovative combination of components results in a highly stable and effective fertilizer product.

[0092] The present invention, through its various demonstrative embodiments, offers a novel and versatile method and composition for producing coated urea fertilizers with enhanced properties, addressing the challenges associated with conventional urea fertilizers while minimizing the environmental impact and production costs. Examples

[0093] Example 1

[0094] Soil preparation

[0095] The soils were collected from the field, dried, screened in a -2mm opening, wetted with 40% of their water holding capacity and kept in closed conditions for 2 weeks for incubation. That way we made sure the soils are homogeneous, fresh, and biologically active.

[0096] Emission test

[0097] 0.5L glass bottles with 3.5cm radius (surface area = 38.5cm 2) were filled with 200 gr soil and 0.042g of broadcasted N (0.09g urea, 0.102g coated urea). A total of 110 Kg N / hectare which is a standard amount for cereal farming. The bottles were connected to the PICARRO equipment, a commercially available gas analyzer that measured NH3, N2O, CH4, CO2 and humidity.

[0098] Different fertilizers were applied to different soils inside closed glass bottles in doses that fit cereal farming. The gasses in the bottles were pumped out and analyzed daily by a commercially available analyzers for NH3 and green house gases.

[0099] Lab temperature was 21 °C.

[0100] 3 repetitions per experiment.

[0101] Table 1 - %N volatilization as NH3

[0102] The results of table 1 are depicted in figure 1. Figure 1 shows a comparison of ammonia volatilization between coated and pristine urea on two different soils within the first 12 days after the fertilization. Figure 2 shows the same thing only for NzO. %N stands for volatilized Nitrogen as gas X divided by applied Nitrogen as urea. According to the results, within the duration of the

[0103] 5 experiment, ammonia and N2O volatilizations were reduce by 70-95% and 80-95% respectively when the urea was coated. Figure 3 relates to the CO2 emissions of these samples and shows a reduction of 29% or 87% when the urea is coated. Here the characteristics of the soil seem to have higher influence on the efficiency of the coating. Table 4 shows some of the characteristics of the soils used in the experiment. The

[0104] 10 characteristics are different and diverse, and it comes to show that our coating can be beneficial in a verity of agronomical systems.

[0105] Table 2 - %N volatilization as N2O

[0106] The results of table 2 are depicted in figure 2.

[0107] Table 3 - CO2Emissions

[0108] The results of table 3 are depicted in figure 3.

[0109] Table 4

[0110] Reference is now made to figure 4 which depicts a graph showing the comparison between coated urea according to the present invention and uncoated urea.

[0111] As can be seen in Figure 4, throughout a 44 day trial the coated urea exhibited diminished N volatilization (as NH3).

[0112] The results of the study as depicted in figure 4 demonstrate the substantial efficiency of the coated granule of the present invention when compared to non-coated urea.

[0113] Example 2

[0114] 14% coating - 0.2 kg of granular urea was screened to a size of 14mm and heated to 85°C. Meanwhile an organic coating was prepared by mixing 70% rosin with 30% wax, heated to 90°C and 28 grams of it was dripped gradually on the urea. Finally, 60 grams of grinded urea was spread in the coating drum and was totally consumed by the organic coating. Therefore, in the end, the relative share of the coating drops to 10.7%.

[0115] Reference is made to figure 5, which depicts the results of the experiment detailed in example 2.

[0116]

[0117] Table 5

[0118]

[0119] Table 6

[0120] Table 7

[0121] As can be seen from figure 5 and from tables 5-7, the coating of the present invention, when incorporated in concentrations of 5% and 14% reduces NH3 emissions by 45-50% and 85-90% respectively, N2O emissions are reduced by about 85% and 100% respectively and CO2 reduced by 60-80% and about 87% respectively, 14 days after fertilization. The coating can be further optimized by 'playing' with the temperatures during the coating process. While this invention has been described in terms of some specific examples, many modifications and variations are possible. It is therefore understood that within the scope of the appended claims, the invention may be realized otherwise than as specifically described.

Claims

What is claimed is:

1. A coated urea granule, comprising: a core consisting of urea; and at least one coating layer encapsulating said core, the coating layer comprising a homogenous mixture of rosin and a lubricant wherein the coating provides enhanced moisture resistance, controlled nutrient release, and reduced volatilization of nitrogen compounds.

2. The granule of claim 1, wherein the rosin is selected from the group including Gum Rosin, Hydrogenated rosin, Tall oil rosin, Wood rosin, Maleic anhydride-modified rosin, Polymerized rosin, Rosin esters or similar solid forms of resin.

3. The granule of claim 2, wherein the rosin is Gum Rosin, wherein the rosin is Gum Rosin, and the coating further provides hydrophobic properties to prevent moisture absorption and clumping.

4. The granule of claim 2, wherein the lubricant is selected from the group including Paraffin wax, Beeswax, Carnauba wax, Candelilla wax, Microcrystalline wax, Soy wax, Polyethylene, Polypropylene, Petroleum jelly, Mineral oil, Palm oil, Castor oil, Lanolin, and Stearic acid or combinations thereof.

5. The granule of claim 4, wherein the ratio of rosin to lubricant in the coating ranges from 10:90 to 90:10, and the coating is formulated to provide a continuous film barrier for enhanced moisture resistance6. The granule of claim 5, wherein the ratio is 70:30 (RosimLubricant), optimized for a balance between coating strength and elasticity, to prevent cracking or stickiness of the coating.

7. The granule of claim 1, further comprising a fertilizer powder incorporated within the coating, wherein the fertilizer powder is selected from the group consisting of Urea, Polyhalite, Ammonium nitrate, Diammonium phosphate (DAP), Monoammonium phosphate (MAP), Potassium chloride (Muriate of Potash), Superphosphate, Ammonium sulfate, Calcium ammonium nitrate (CAN), Ammonium phosphates, Triple superphosphate (TSP), Potassiumnitrate, Potassium sulfate, Sodium nitrate, Nitrogen-phosphorus-potassium (NPK) blends, Ammonium chloride, Calcium nitrate, Ammonium polyphosphate, Magnesium sulfate (Epsom salt), Micronutrient fertilizers, or combinations thereof.

8. The granule of claim 7, wherein said fertilizer powder is urea powder, and the addition of the fertilizer powder prevents aggregation of the granules and enhances the rheology and uniform distribution of the coating.

9. The granule of claim 1, wherein the coating comprises a concentration of 5- 7% w / w of the total granule weight, providing an effective moisture barrier while minimizing the amount of coating material required.

10. A process for producing a fertilizer granule, comprising: preparing a core consisting essentially of granular urea; heating the granular urea to a temperature ranging from 70°C to 120°C; adding a combination of rosin and lubricant to form coated granules, wherein the combination of rosin and lubricant becomes liquid upon exposure to the heated granular urea and coats the core; and applying a fertilizer powder to the coated granules.

11. The process of claim 10, wherein the fertilizer powder is selected from the group including Urea, Polyhalite, Ammonium nitrate, Diammonium phosphate (DAP), Monoammonium phosphate (MAP), Potassium chloride (Muriate of Potash), Superphosphate, Ammonium sulfate, Calcium ammonium nitrate (CAN), Ammonium phosphates, Triple superphosphate (TSP), Potassium nitrate, Potassium sulfate, Sodium nitrate, Nitrogen- phosphorus-potassium (NPK) blends, Ammonium chloride, Calcium nitrate, Ammonium polyphosphate, Magnesium sulfate (Epsom salt), Micronutrient fertilizers (e.g., zinc sulfate, copper sulfate) or combinations thereof.

12. The process of claim 10, wherein the fertilizer powder is urea powder.

13. The process of claim 11, wherein the particle size of the fertilizer powder is less than 500 microns.

14. The process of claim 10, wherein the ratio of the rosin to lubricant is 70:30 and the fertilizer powder is applied at a concentration of 5-20% w / w of thetotal granule weight, resulting in enhanced resistance to moisture and controlled nutrient release.

15. The process of claim 10, wherein the coated granules are further subjected to an additional coating step, adding another layer of material to improve resistance to environmental degradation or to modify the release rate of nutrients.

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