Fertilizer particle comprising a protein hydrolysate as biostimulant

Abstract

The present invention relates to a fertilizer particle comprising two or more of from 1.0 to 30 wt.% of nitrogen being present as calcium ammonium nitrate (CAN), and from 0.0001 to 5.0 weight% of protein hydrolysate as a biostimulant, based on the total weight of the fertilizer particle. The present invention furthermore relates to a method to produce such fertilizer particles.

Description

[0001] FERTILIZER PARTICLE COMPRISING A PROTEIN HYDROLYSATE AS BIOSTIMULANT

[0002] Field of the disclosure

[0003] The present disclosure is related to the field of fertilizers, in particular fertilizer products comprising ammonium nitrate, and more in particular calcium ammonium nitrate.

[0004] Background information

[0005] Nitrogen is one of the most important nutrients required by plants to grow. It is involved in several physiological processes, such as chlorophyll synthesis and protein synthesis, which are crucial for the development of a plant. Nitrogen is mainly applied in four forms: urea, ammonium ions, nitrate ions, and organic sources, such as proteins. Nitrate ions are readily absorbed by plants and represent a fastacting source of nitrogen. Phosphorus and potassium are two macronutrients, which, in addition to nitrogen, are required by plants. Nitrate ions are the preferred source of nitrogen for most agricultural plants, which they can absorb through their roots. Ammonium ions can also be absorbed, although at a slower rate.

[0006] Soils naturally contain a lot of microorganisms, such as bacteria and fungi, and some of them are capable of transforming ammonium into nitrate, whereas others can transform nitrate into other nitrogen forms, such as nitrous oxide.

[0007] Ammonium nitrate-based fertilizers are commonly used today in agriculture and have several advantages: high nitrogen content (usually around 25-27 weight%), and fast release of nitrogen in the soil due to high water solubility.

[0008] Other nitrogen-containing fertilizers include NPK, NP or PK fertilizers, which comprise two or more of nitrogen, phosphorus, and potassium. These fertilizers often contain nitrogen in the form of ammonium ions and / or nitrate ions.

[0009] Recently, a new type of agricultural inputs has been discovered: biostimulants. Biostimulants are organic compounds that trigger positive physiological changes in plants. Biostimulants can be absorbed by the roots or leaves of a plant, and they interact with enzymes present in the plant and in the soil to modify the plant's behavior. The presence of biostimulants in the particle provides new benefits and / or improves known benefits to the plant receiving the fertilizer effect, such as increasing the nutrient use efficiency. The nutrient use efficiency measures the amount of nutrient absorbed by a plant compared to the amount of nutrient supplied to it as fertilizer. Biostimulants can furthermore have other advantages, such as solubilizing nutrients in soil, and improving resistance to abiotic stresses. So, there is a need to combine biostimulants with nitrogen-containing fertilizers into a single solid product. Summary of the disclosure

[0010] It has been found that it is possible to prepare homogeneous fertilizer particles comprising a biostimulant. The biostimulant is added during the fertilizer production process and is evenly distributed within the fertilizer. This ensures that the biostimulant is released at the same time as the nutrient comprised in the fertilizer.

[0011] The biostimulant can increase one or more parameters of plants, such as shoot dry matter, root dry matter, leaf area, and phosphorus use efficiency.

[0012] In a first aspect, the present disclosure provides a homogeneous fertilizer particle comprising: from 1.0 to 30 weight% of nitrogen being present as calcium ammonium nitrate (CAN), and from 0.0001 to 5.0 weight% of a protein hydrolysate as a biostimulant, based on the total weight of the fertilizer particle.

[0013] In another aspect, the present disclosure provides a method for producing homogeneous fertilizer particles, the method comprising: a. providing a solid, molten, or a combination thereof (slurry), calcium ammonium nitrate (CAN) starting material comprising from 1.0 to 30.0 wt.% of nitrogen, based on the total weight of the material; b. optionally, modifying the properties of the starting material by mixing, pH-value adjustments, heating, cooling, and / or evaporating; c. processing the material into homogenous fertilizer particles, more in particular with a particle size of from 0.1 to 5.0 mm, d. adding from 0.0001 to 5.0 wt.% of a protein hydrolysate, based on the total weight of the material, in step a, b, and / or c, e. optionally, modifying the particle surface with coatings and / or other surface-active ingredients, f. optionally, adding one or more fillers, secondary nutrients, micronutrients, and / or other biostimulants, during one or more of the steps a, b, c, d, and e.

[0014] Detailed description of the disclosure

[0015] Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

[0016] All references cited in this description are hereby deemed to be incorporated in their entirety by way of reference.

[0017] As used herein, the following terms have the following meanings: "A" , "an", and "the" as used herein refers to both singular and plural referents unless the context clearly dictates otherwise. By way of example, "a compartment" refers to one or more than one compartment.

[0018] "About" as used herein referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of + / -20 % or less, in particular + / -10 % or less, more in particular + / -5 % or less, even more in particular + / -1 % or less, and still more in particular + / - 0.1 % or less of and from the specified value, in so far such variations are appropriate to perform in the disclosed invention. However, it is to be understood that the value to which the modifier "about" refers is itself also specifically disclosed.

[0019] "Comprise", "comprising", and "comprises" and "comprised of" as used herein are synonymous with "include", "including", "includes" or "contain", "containing", "contains" and are inclusive or open- ended terms that specifies the presence of what follows e.g., component and do not exclude or preclude the presence of additional, non-recited components, features, element, members, steps, known in the art or disclosed therein.

[0020] The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within that range, as well as the recited endpoints.

[0021] The expression "weight percent", "%wt.", "weight%" or "wt.%", here and throughout the description unless otherwise defined, refers to the relative weight of the respective component based on the overall weight of the formulation.

[0022] In a first aspect, the present disclosure provides a homogeneous fertilizer particle comprising: from 1.0 to 30 weight% of nitrogen being present as calcium ammonium nitrate (CAN), and from 0.0001 to 5.0 weight% of a protein hydrolysate as a biostimulant, based on the total weight of the fertilizer particle.

[0023] As used herein, a homogeneous material relates to a material where the local concentration in different elements is identical in all parts of the material. However, the material may not necessarily be monophasic, i.e., it may contain chemical compounds in different states. For example, a fertilizer particle may comprise a main component, also called a matrix, and solid particles of a different material evenly distributed within the matrix. Such a fertilizer particle would be considered homogeneous for the purpose of this disclosure if the solid particles are equally distributed within the fertilizer particle.

[0024] A Calcium Ammonium Nitrate (CAN) fertilizer is a fertilizer composition comprising at least 50 weight% of ammonium nitrate (AN), and typically between 50 and 90 wt.% of AN, and a calcium-containing compound selected from the group consisting of dolomite, lime, calcium carbonate, and mixtures thereof. In some embodiments, the fertilizer particle comprises the fertilizer particle comprises between 17.0 and 30.6 wt.% of nitrogen, more in particular between 25.0 and 29.0 wt.% of nitrogen present as CAN, based on the total weight of the fertilizer particle.

[0025] Protein hydrolysates are compositions obtained by hydrolysis of proteins. A protein hydrolysate comprises amino-acids and peptides of various length, for example from 2 to 20 amino-acids. A protein hydrolysate may be of vegetable origin, animal origin, or a mixture of both. It has been observed that protein hydrolysate comprised in fertilizer particles can increase one or more parameters of plants, such as shoot dry matter, root dry matter, leaf area, and phosphorus use efficiency.

[0026] Protein hydrolysates can be obtained from a variety of sources, including animal sources, such as meat- bone-meal, and vegetable sources, such as soybean meal. It has been observed that protein hydrolysates comprised in fertilizer particles can increase one or more parameters of plants, such as shoot dry matter, root dry matter, leaf area, and phosphorus use efficiency.

[0027] In some embodiments, the fertilizer particle comprises from 0.01 to 1.50 weight%, more in particular from 0.03 to 0.55 wt.%, most in particular from 0.10 to 0.20 wt.% protein hydrolysate, based on the total weight of the fertilizer particle.

[0028] In some embodiments, the fertilizer particle comprises one or more other biostimulants selected from the group consisting of a humic acid, a fulvic acid, a seaweed extract, an amino acid, a peptide comprising at least two amino acids, a polysaccharide, a lignosulfonate, and mixtures thereof. It was found that different types of biostimulants were suitable to be added in a fertilizer production process. The total amount of biostimulants is more in particular present in the fertilizer particle in an amount of between 0.0001 and 5.0 weight%, based on the total weight of the fertilizer particle.

[0029] Humic and fulvic acids may be obtained from the process of leonhardite, which is a natural raw material from the decomposition of organic matter. Humic and / or fulvic acids may be present as a salt. Humic and fulvic acids are complex organic molecules comprising carboxylic acid groups, so humic and fulvic salts, also called humate and fulvate, can be prepared by mixing the acid with a base. It has been observed that humic and fulvic acids comprised in fertilizer particles can increase one or more parameters of plants, such as shoot dry matter, root dry matter, leaf area, and phosphorus use efficiency. In some embodiments, the fertilizer particle comprises from 0.005 to 1.5 weight% of a mixture of humic and fulvic acids, more in particular from 0.015 to 0.16 wt.%, most in particular from 0.05 to 0.07 wt.%, based on the total weight of the fertilizer particle.

[0030] It has been observed that polysaccharides comprised in fertilizer particles can increase one or more parameters of plants, such as shoot dry matter, root dry matter, leaf area, and phosphorus use efficiency. Chitosan is a linear polysaccharide produced by several marine species, such as shrimp, lobster, and crab. It comprises p-linked D-glucosamine and N-acetyl-D-glucosamine. In some embodiments, the fertilizer particle comprises at least one polysaccharide, more in particular chitosan, present in an amount of from 0.0005 to 0.1 weight%, more in particular from 0.001 to 0.011 wt.%, most in particular from 0.008 to 0.012 wt.%, based on the total weight of the fertilizer particle.

[0031] Lignosulfonate compounds are by-products of the paper industry. These compounds are polymers and may be highly branched polymers comprising phenyl propane units, which have a broad distribution of size. Lignosulfonates comprise sulfonate groups and can comprise sodium, potassium, or calcium as counter-ions. It has been observed that lignosulfonate compounds comprised in fertilizer particles can increase one or more parameters of plants, such as shoot dry matter, root dry matter, leaf area, and phosphorus use efficiency.

[0032] In some embodiments, the fertilizer particle comprises one or more lignosulfonate compounds in an amount of from 0.01 to 1.50 weight%, more in particular from 0.03 to 0.55 wt.%, most in particular from 0.10 to 0.20 wt.%, based on the total weight of the fertilizer particle.

[0033] In some embodiments, the lignosulfonate compound is a calcium lignosulfonate.

[0034] In some embodiments, the fertilizer particle comprises at least one filler selected from the group consisting of dolomite, MgO, lime, calcium sulfate, clay and mixtures thereof. Dolomite (CaMg(CO3)2) and lime (usually CaO or Ca(OH)z) are calcium-containing fillers, as well as calcium sulphate (CaS04), which is commonly known as gypsum. Clay is a broad term for a variety of aluminosilicates and can comprise calcium, but does not always do. It is remarked that, when a calcium-nitrate containing filler is present, the calcium ammonium nitrate is formed by reaction of the calcium out of the filler with ammonium nitrate. Filler materials are used in some fertilizer production processes, in particular processes for producing an ammonium nitrate-based fertilizer. Ammonium nitrate is a very good fertilizer material since it contains a high proportion of nitrogen and it is easily absorbed by plants. However, pure ammonium nitrate and compositions containing at least 80 weight% of ammonium nitrate are highly explosive. To reduce the explosive risk during production, storage, transport, and use, a non-reactive filler is often added to the production process. It has been found that fillers, such as dolomite, lime, and calcium sulphate, are suitable to be used. These fillers significantly reduce the explosive risk of the fertilizer. In addition, these fillers advantageously contain nutrients, such as calcium and optionally magnesium, required by plants.

[0035] In some embodiments, the fertilizer particle comprises from 1.0 to 30 weight%, from 5.0 to 30 weight%, from 10 to 30 weight%, from 1.0 to 25 weight%, from 5.0 to 25 weight%, or from 10 to 30 weight% of the at least one filler, based on the total weight of the fertilizer particle.

[0036] In some embodiments, the fertilizer particle comprises one or more element(s) selected from the group consisting of calcium, magnesium, sulphur, boron, manganese, selenium, zinc and sodium, and mixtures thereof are added to the molten material. Sulfur, magnesium, and calcium are called secondary nutrients. Boron, copper, iron, manganese, and zinc are called micronutrients. It is remarked that one or more other element(s) out of cobalt, copper and iron, can be present in (calcium) ammonium nitrate fertilizers, this due to impurities present in the raw material.

[0037] In some embodiments, the fertilizer particle further comprises one or more components selected from the group consisting of magnesium sulfate, sodium nitrate, potassium nitrate, magnesium nitrate, aluminum sulfate, struvite, biotite, and mixtures thereof. These components can be used in fertilizers to provide secondary nutrients and micronutrients and to improve the physical properties, such as caking tendency, dusting tendency, particle strength, and water absorption, of the fertilizer particle.

[0038] In some embodiments, the fertilizer particle has a particle size ranging from 0.1 to 5.0 mm.

[0039] In another aspect, the present disclosure provides a method for producing homogeneous fertilizer particles, the method comprising the steps of a. providing a solid, molten, or a combination thereof (slurry), calcium ammonium nitrate (CAN) starting material comprising from 1.0 to 30.0 wt.% of nitrogen, based on the total weight of the material; b. optionally, modifying the properties of the starting material by mixing, pH-value adjustments, heating, cooling, and / or evaporating; c. processing the material into homogenous fertilizer particles, more in particular with a particle size of from 0.1 to 5.0 mm, d. adding from 0.0001 to 5.0 wt.% of a protein hydrolysate, based on the total weight of the material, in step a, b, and / or c, e. optionally, modifying the particle surface with coatings and / or other surface-active ingredients, f. optionally, adding one or more fillers, secondary nutrients, micronutrients, and / or other biostimulants, during one or more of the steps a, b, c, d, and e.

[0040] In some embodiments, the CAN starting material comprising between 17.0 and 30.6 wt.% of nitrogen, more in particular between 25.0 and 29.0 wt.% of nitrogen, based on the total weight of the material, is added in step a.

[0041] In some embodiments, in step d, the one or more protein hydrolysates are added in an amount of from 0.01 to 1.50 weight%, more in particular from 0.03 to 0.55 wt.%, most in particular from 0.10 to 0.20 wt.% protein hydrolysate, based on the total weight of material, in steps a, b and / or c.

[0042] In some embodiments, the one or more protein hydrolysates are added as a dry composition, for example, a dry powder. In some embodiments, the lignosulfonate compound is added as a liquid composition, for example, an aqueous solution or an aqueous suspension.

[0043] In some embodiments, in step d, one or more dry vegetable protein hydrolysates and / or one or more aqueous vegetable protein hydrolysate solutions are added as the protein hydrolysate(s) in an amount of from 0.01 to 1.50 weight%, more in particular from 0.03 to 0.55 wt.%, most in particular from 0.10 to 0.20 wt.%, based on the total weight of the molten material, in steps a, b and / or c. Furthermore, in some embodiments, in step f, one or more fillers, more in particular in an amount of from 1.0 to 30.0 wt.% based on the total weight of the material, selected from the group consisting of dolomite, MgO, lime, calcium sulfate, and / or clay, and mixtures thereof, are added during one or more of the steps a, b, c, d, and e.

[0044] Also, in some embodiments, in step f, one or more secondary nutrients selected from the group consisting of calcium, magnesium, sulphur, sodium, and mixtures thereof, and / or one or more micronutrients selected from the group consisting of boron, manganese, selenium, zinc, molybdenum are added during one or more of steps a, b, c, d, and / or e. It is remarked that one or more other element(s) out of cobalt, copper and iron, can be present in (calcium) ammonium fertilizer particles, this due to impurities present in the raw material.

[0045] In order to produce fertilizer particles at a high rate, at several hundreds of kilos a day, production methods using molten materials have been developed. Molten materials can be converted into a solid particulate compositions with a variety of methods and devices, such as a prilling tower, a pan granulator, a fluidized bed granulator, a drum granulator, a spherodizer, and a pugmill, whichever is applicable. The particles made by these methods have the same chemical composition as the molten material.

[0046] Depending on the type of process, the other biostimulants, the one or more fillers, the second nutrients, and / or the micronutrients, can be added in a different step of the process.

[0047] In case of a fluidized bed granulator, a (pre-)mixing vessel is present prior to a granulation device which are in fluid connection with each other by means of piping. Consequenlty, step b is present and the one or more fillers, the secondary nutrients, the micronutrients, and / or the (other) biostimulants are added in step b, more in particular in the mixing vessel. Depending on the concentration of the (other) biostimulants, these can be added into the mixing vessel, or in the piping to the granulator.

[0048] A pugmill and blunger granulator have no pre-mixing vessel. In these granulators, or in other words if the method is a blunger or a pugmill process, no step separate mixing step b is present and the one or more fillers, the secondary nutrients, the micronutrients, and / or the other biostimulants are added in step c, i.e. in the granulator itself where also the mixing is done.

[0049] In the optional step b, the properties of the starting material may be modified by mixing, adjusting the pH-value, heating, cooling and / or evaporating. The starting material from step a may optionally be mixed in step b to become homogeneous, meaning that the one or more protein hydrolysates that are added in step d during steps a, b, and / or c, and optionally, when added in step a, b, c, and / or d, the other biostimulants, the one or more fillers, the second nutrients, and the micronutrients, are evenly distributed within the molten material.

[0050] Once the desired material is obtained in step b, the material is processed in step c into homogeneous fertilizer particles. Some production techniques, such as prilling and spherodizing, require a homogeneous material to produce homogenous particles. Other techniques do not require a homogeneous material to produce homogenous particles, because the production technique homogenizes the composition during its production for example, in the drum or pugmill granulation process, by direct combination of solids with the molten material in the granulator.

[0051] In some embodiments, the homogeneous fertilizer particles obtained in the method of the present disclosure have a particle size ranging from 0.1 to 5.0 mm. Modern agriculture machinery, in particular fertilizer spreaders, is often configured to manipulate fertilizer particles having a size of a few millimeters.

[0052] In some embodiments, the processing of the material as performed in step c comprises producing homogeneous particles using a device selected from the group consisting of a prilling tower, a pan granulator, a fluidized bed granulator, a drum granulator, a spherodizer, and a pugmill, whichever is applicable.

[0053] In some embodiments, in an optional step e, the homogeneous fertilizer particles obtained from the processing of material as performed in step c, are coated with a coating composition which can comprise one or more fillers, secondary nutrients, micronutrients, and / or other biostimulants as mentioned above. These coating compositions may be applied to the fertilizer particles to modify their chemical composition and / or to improve their physical properties, such as particle strength, caking property, dusting property, and swelling property.

[0054] In some embodiments, the homogeneous fertilizer particles obtained from the processing are fertilizer particles according to the present disclosure.

[0055] Example 1

[0056] A molten material (= melt) comprising 77 weight% of ammonium nitrate (AN) and 22 weight% of dolomite was prepared and maintained at around 160 °C. The ammonium nitrate and the dolomite together form calcium ammonium nitrate (CAN). As can be seen in Table 1 below, in 3 entries a dry vegetable protein hydrolysate was added to the CAN melt as a biostimulant, and in 3 entries a 50 wt.% of dry matter of an aqueous solution was added to the CAN melt, which was then stirred for 5 min, before being cooled on a plate and broken down in small pieces with a size below 5.0 mm.

[0057] Table 1

[0058] These particulated fertilizers, i.e. entries 1 to 6 as mentioned in Table 1 above, and a control without the protein hydrolysate as biostimulant, were then tested in an agronomic trial, i.e. maize was seeded in a 7.5 L pot containing 9.0 kg of substrate. The substrate comprised 70 weight% of fine quartz sand and 30 weight% of low fertility soil. Low fertility conditions were established to ensure an ideal environment for testing of the fertilizer products. Pots were watered to field capacity prior to sowing and then watered three times a week throughout the trial. The trial was placed in a controlled environment glasshouse allowing for full control of light and temperature. Temperature was maintained at 20-25°C for 16 hours during the day and 16-18°C for 8 hours at night.

[0059] Four seeds were initially sown per pot to a depth of 2.5 to 3.0 cm. There were 5 replicates per treatment arranged in randomized complete block design (RCBD). At 15 DAS (Days After Sowing), pots were thinned to just the two strongest plants, the majority of plants were at growth stage 13 (BBCH13) when thinned. The pots received 50 % of the ammonium nitrate fertilizers (with or without protein hydrolysate as biostimulant) and 50% of the remaining macro and micronutrients at 15 Days after sowing (DAS). The pots received the remaining 50% ammonium nitrate fertilizer (with or without protein hydrolysate as biostimulant), and 50% macro and micronutrients at 30 DAS. The sum of nutrient application rates were: N (with or without protein hydrolysate biostimulant, 20 mg N / kg), and macro and micronutrients (P, K, Mg, Ca, S, Fe, Mn, Zn, B, Cu, Mo at 20, 85, 12, 40, 62, 3.8, 2.6, 0.5, 0.5, 0.5 and 0.1 mg / kg, respectively). Plants were harvested at 50 DAS, partitioned, dried, and stored for later laboratory analyses.

[0060] In table 2 below, an overview is given of the shoot dry matter expressed in g / plant for the different entries as mentioned in Table 1 above. The shoot dry matter is measured by drying harvested shoot to constant weight at 60°C.

[0061] Table 2

[0062] Conclusion

[0063] It can be seen that all the entries 1 to 6 fertilizer compositions comprising protein hydrolysate as the biostimulant perform better than the entry 0 fertilizer composition without protein hydrolysate (= control).

[0064] Example 2

[0065] A CAN melt comprising 77 weight% of AN and 22 weight% of dolomite was prepared and maintained at around 160 °C. The ammonium nitrate and the dolomite together form the CAN. Protein hydrolysate was added as a biostimulant to this molten material (see table 1), which was stirred for 5 min, before being cooled on a plate and broken down into small pieces with a size below 5.0 mm.

[0066] The solids were then tested in a second scientific agronomic trial: Maize plants are grown in a controlled greenhouse in 11 L pots filled with 70% sand and 30% low-P soil (wt. / wt.). 50% supply of micronutrients were applied by 100 ml / pot of drenched nutrient solution during soil preparation. Fertilizer modality is applied before sowing, by mixing it in the entire substrate volume. Sowing of 4 seeds / pot (maize (Zea mays L.)), covered with 3 cm of substrate, thinned to 2 plants per pot at 14 DAS (days after sowing). There were 5 replicates per treatment arranged in CRD. At 20 DAS: Supplementary N fertilization was applied to 100% of the plant requirement and accompanied with spot irrigation to drench the nutrients into the soil. The sum of nutrient application rates were: NPK (with or without protein hydrolysate, 150, 15 and 253 mg / kg, N, P and K respectively), and other macro and micronutrients (Mg, Ca, S, Cl, Fe, Mn, Zn, B, Cu, Mo at 12, 200, 70, 83, 7.7, 5.1, 1.1, 1.0, 1.1 and 0.26 mg / kg, respectively). All 5 replicates were harvested at 54 DAS, partitioned, dried, and stored for later laboratory analyses.

[0067] In Table 3 below, the shoot dry matter expressed in g / plant of the maize plants treated with the entry fertilizer composition 0 without protein hydrolysate (= control) and the entries 1 to 6 fertilizer compositions as mentioned in Table 1 above are shown. The shoot dry matter is measured by drying harvested shoot of the maize plants to constant weight at 60°C.

[0068] Table 3

[0069] Conclusion

[0070] It can be seen that all the entries 1 to 6 fertilizer compositions comprising protein hydrolysate as the biostimulant perform better than the entry 0 fertilizer composition without protein hydrolysate (= control).

Claims

Claims1. A homogeneous fertilizer particle comprising: from 1.0 to 30 weight% of nitrogen being present as calcium ammonium nitrate (CAN), and from 0.0001 to 5.0 weight% of a protein hydrolysate as a biostimulant, based on the total weight of the fertilizer particle.

2. The homogeneous fertilizer particle according to claim 1, wherein the fertilizer particle comprises the protein hydrolysate in an amount of from 0.01 to 1.50 weight%, more in particular from 0.03 to 0.55 wt.%, most in particular from 0.10 to 0.20 wt.%, based on the total weight of the fertilizer particle.

3. The homogeneous fertilizer particle according to claim 1 or 2, wherein the fertilizer particle comprises between 17.0 and 30.6 wt.% of nitrogen, more in particular between 25.0 and 29.0 wt.% of nitrogen present as CAN, based on the total weight of the fertilizer particle.

4. The homogeneous fertilizer particle according to any one of claims 1 to 3, wherein the fertilizer particle comprises one or more other biostimulants selected from the group consisting of a humic acid, a fulvic acid, a seaweed extract, a protein hydrolysate comprising an amino acid, or a peptide comprising at least two amino acids, a polysaccharide, a lignosulfonate compound, and mixtures thereof.

5. The homogeneous fertilizer particle according to any one of the preceding claims, further comprising at least one filler selected from the group consisting of dolomite, MgO, lime, calcium sulfate, clay, and mixtures thereof.

6. The homogeneous fertilizer particle according to claim 5, comprising from 1.0 to 30.0 weight% of the at least one filler, based on the total weight of the fertilizer particle.

7. The homogeneous fertilizer particle according to any one of the preceding claims, further comprising one or more element(s) selected from the group consisting of calcium, magnesium, sulphur, boron, manganese, selenium, zinc and sodium, and mixtures thereof.

8. The homogeneous fertilizer particle according to any one of claims 1 to 7 , having a particle size ranging from 0.1 to 5.0 mm.

9. A method for producing homogeneous fertilizer particles, the method comprises the steps of a. providing a solid, molten, or a combination thereof (slurry), calcium ammonium nitrate (CAN) starting material comprising from 1.0 to 30.0 wt.% of nitrogen, based on the total weight of the material; b. optionally, mixing the molten material, c. processing the material into homogenous fertilizer particles, more in particular with a particle size of from 0.1 to 5.0 mm, d. adding from 0.0001 to 5.0 wt.% of a protein hydrolysate, based on the total weight of the material, in step a, b, and / or c, e. optionally, modifying the particle surface with coatings and / or other surface-active ingredients, f. optionally, adding one or more fillers, secondary nutrients, micronutrients, and / or other biostimulants, during one or more of the steps a, b, c, d, and e.

10. A method according to claim 9, wherein in step d, the one or more protein hydrolysates, and more in particular one or more dry vegetable protein hydrolysates, and / or one or more aqueous vegetable protein hydrolysate solutions, are added in an amount of from 0.01 to 1.50 weight%, more in particular from 0.03 to 0.55 wt.%, most in particular from 0.10 to 0.20 wt.%, based on the total weight of the fertilizer particle, in step a, b, and / or c.

11. A method according to claim 9 or 10, wherein the CAN starting material comprising between 17.0 and 30.6 wt.% of nitrogen, more in particular between 25.0 and 29.0 wt.% of nitrogen present as CAN, is provided in step a.

12. A method according to any one of claims 9 to 11, wherein, when the method is a prilling, a spherodizing, a drum granulation, or a fluidized bed granulation process, the one or more fillers, the secondary nutrients, the micronutrients, and / or the other biostimulants, are added in step b, when the method is a blunger or a pugmill process, the one or more fillers, the secondary nutrients, the micronutrients, and / or the other biostimulants are added in steps c.

Images