Fertilizer particles coated with micronutrient source

Abstract

FIELD: agrochemistry.SUBSTANCE: fertilizer particle comprises a core and an outer layer of a modifier covering the core, wherein the modifier comprises a compound containing a micronutrient, and said compound is completely dissolved in a solvent. The solvent is selected from the group consisting of glycerol, monoethylene glycol, monopropylene glycol, diethylene glycol, 2-(2-ethoxyethoxy)-ethan-1-ol and mixtures thereof. The specified solvent has a melting point below 15°C and makes up from 30 to 90% of the modifier by weight. The modifier contains at least 30 g / l of a micronutrient selected from the group consisting of copper, manganese, molybdenum and zinc. The micronutrient-containing compound is a molybdenum salt or an ethylenediaminetetraacetate chelate of copper, manganese, or zinc. The modifier has a pH from 5.0 to 7.0. The invention also relates to a method for producing such a fertilizer particle.EFFECT: production of a fertilizer particle that can be coated with an effective source of one or more micronutrients without negatively affecting the quality of the fertilizer.11 cl, 1 tbl, 14 ex

Description

[0001] Technical field

[0002] The present invention relates to the field of fertilizer particles, in particular fertilizer particles coated with a composition containing a micronutrient.

[0003] Technology Level

[0004] In agriculture, the term micronutrients refers to a group of elements consisting of boron, copper, iron, manganese, molybdenum, and zinc. Most crops require one or more of these elements for optimal growth. Some of these elements can be found naturally in the soil, but farmers often need to supply crops with one or more of these elements through fertilizer application to meet their needs.

[0005] Micronutrients can be supplied to crops in a variety of ways, for example, solid micronutrients can be distributed over fields by hand or mechanical spreading; or a solution, often aqueous, containing the micronutrient is sprayed onto the foliage of crops (foliar application); or the micronutrient can be dissolved and applied to the crop in irrigation water (fertigation).

[0006] A convenient way to supply crops with micronutrients is to apply a coating composition containing a micronutrient to fertilizer particles containing primary or secondary nutrients, such as nitrogen, phosphorus, potassium, calcium, magnesium, or sulfur. The advantage of this method is that it reduces the farmer's workload by allowing multiple micronutrients to be applied in a single application, and it also reduces water consumption on the farm. Plants require micronutrients in small quantities, and this requirement can be met by applying a thin layer of the coating composition to the fertilizer particles.

[0007] Micronutrients can also be incorporated into fertilizer particles through the process of pressing or granulating the particles, but practical recommendations for large-scale production suggest that this approach is difficult to meet the widely varying nutrient requirements of different crops and different soil types.

[0008] Document GB 2513232 (Yara, 2014) discloses a method for producing fertilizers coated with an oil-based composition containing a micronutrient source. The micronutrient source is suspended in the oil-based composition and uniformly coated onto the particles. This method provides an effective method for delivering micronutrients through solid fertilizers intended for application to soil. However, oil-based compositions are not ideal for fertigation, as the oil-based coatings will not completely dissolve in water, leading to clogging in the irrigation system.

[0009] Water-based formulations containing micronutrients are not suitable for application to fertilizer particles because water adversely affects the physical properties such as particle strength and aggregation tendency of particles for processing, transportation and storage, and their distribution in fields.

[0010] Therefore, there is a need to develop new coating compositions containing micronutrients that contain minimal amounts of water and oil.

[0011] Brief description of the invention

[0012] It has been surprisingly found that compositions containing a micronutrient dissolved in a solvent selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof, wherein the solvent has a melting point below 15°C, are very suitable for coating fertilizers, thus providing a simple and flexible method by which solid fertilizers can be coated with an effective source of one or more micronutrients without negatively affecting the quality of the fertilizers.

[0013] According to the first aspect of the invention, a fertilizer particle is proposed, comprising a core and an outer layer of a modifier covering the core, containing a component containing a micronutrient, wherein said compound is dissolved in a solvent, wherein said solvent is selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof, said solvent has a melting point below 15°C, said solvent constitutes from about 30 to about 90% by weight of the modifier and said micronutrient is selected from the group consisting of copper, manganese, molybdenum and zinc. In an alternative aspect, the micronutrient can be boron.

[0014] In another aspect, a method for producing a fertilizer particle according to the present invention is provided, wherein the fertilizer particle comprises a modifier layer comprising the steps of: (a) providing a fertilizer core particle; and (b) applying a modifier comprising a compound containing a micronutrient, wherein said compound is dissolved in a solvent, wherein said solvent is selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof, said solvent has a melting point below 15°C, said solvent constitutes from about 30 to about 90% by weight of the modifier, said micronutrient is selected from the group consisting of copper, manganese, molybdenum and zinc, and said modifier optionally contains urea and / or acid. In an alternative aspect, the micronutrient may be boron.

[0015] According to another aspect, a liquid composition is provided that includes a compound containing a micronutrient, wherein said compound is dissolved in a solvent, wherein said solvent is selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof, said solvent has a melting point below 15°C, said solvent constitutes from about 30 to about 90% by weight of the liquid composition, and said micronutrient is selected from the group consisting of copper, manganese, molybdenum and zinc. In an alternative aspect, the micronutrient can be boron.

[0016] According to another aspect, the use of a composition as a coating agent for fertilizer particles is proposed, comprising a compound containing a micronutrient selected from the group consisting of copper, manganese, molybdenum and zinc, wherein the compound is dissolved in a solvent selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof having a melting point below 15°C, and optionally urea and / or citric acid. In an alternative aspect, the micronutrient may be boron.

[0017] Detailed description of the invention

[0018] Unless otherwise defined, all terms used in the disclosure, including technical and scientific terms, have the meaning commonly understood by one of ordinary skill in the art to which this invention pertains. Definitions of terms are included for additional guidance to better understand the essence of the present invention.

[0019] All references provided in this description are deemed to be incorporated by reference in their entirety.

[0020] In the context of this document, the following terms have the following meanings:

[0021] Singular terms used herein refer to both singular and plural forms unless the context clearly dictates otherwise. For example, "compartment" refers to one or more compartments.

[0022] "About" as used herein with respect to a measurable value such as a parameter, quantity, time duration, etc., is intended to encompass variations of + / - 20% or less, preferably + / - 10% or less, more preferably + / - 5% or less, even more preferably + / - 1% or less, and even more preferably + / - 0.1% or less from the stated value, to the extent that such variations are consistent with the implementation in the disclosed invention. However, it should be understood that the value to which the modifier "about" refers is itself also specifically disclosed.

[0023] “Comprise,” “comprising,” “contains,” and “consists of,” as used herein, are synonymous with “include,” “including,” “includes,” or “contain,” “comprising,” “contains,” and are inclusive or open-ended terms that specify the presence of what follows, such as a component, and do not exclude or allow the presence of additional, unlisted components, features, elements, members, steps, known in the art or disclosed herein.

[0024] Enumerating a numeric range by its endpoints includes all numbers and fractions within the range, as well as the specified endpoints.

[0025] The expression "mass %", "mass percent", "% w / w", "mass %" or "% wt", here and throughout the description, unless otherwise specified, refers to the mass of the corresponding component relative to the total mass of the composition.

[0026] According to the first aspect of the invention, a fertilizer particle is proposed, comprising a core and an outer layer of a modifier covering the core, wherein the modifier comprises a component containing a micronutrient, wherein said compound is dissolved in a solvent, wherein said solvent is selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof, said solvent has a melting point below 15°C, said solvent constitutes from about 30 to about 90% by weight of the modifier, and said micronutrient is selected from the group consisting of boron, copper, manganese, molybdenum and zinc.

[0027] It was found that it is possible to obtain a fertilizer particle containing a large amount of micronutrient by coating a fertilizer core containing nutrients with a modifier containing a micronutrient component dissolved in a solvent.

[0028] The solvent is selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols, and mixtures thereof, and the solvent has a melting point below 15°C. It was found that polyhydric alcohols and / or their derivatives are capable of dissolving a wide range of micronutrient components, and the resulting liquid compositions can be applied to fertilizer particles using standard coating methods.

[0029] Polyhydric alcohols refer to a group of molecules containing a carbon chain, which may be linear or branched, and at least two hydroxy groups. The group of polyhydric alcohols contains diols, also called glycols, such as 1,2-ethanediol, also called ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol; triols such as 1,2,3-propanetriol, also called glycerol.

[0030] Polyhydric alcohol derivatives include the compounds mentioned above in which one of the hydroxy groups has been substituted or modified. For example, the hydroxy group can be converted into an ether, ester, or carbonate. Polyhydric alcohol derivatives also include polymers of the compounds mentioned above, such as diethylene glycol, triethylene glycol, and any polyethylene glycol with a melting point below 15°C. Polyhydric alcohol derivatives also include derivatives of the polymers mentioned above, such as monoethers and diesters of polyethylene glycol, such as monomethyl diethylene glycol, monoethylene glycol, monopropyl diethylene glycol, monobutyl diethylene glycol, dimethyl diethylene glycol, diethylene glycol, dipropyl diethylene glycol, dibutyl diethylene glycol.

[0031] In one embodiment, the polyhydric alcohol derivatives comprise polymers of polyhydric alcohols, wherein the polymers comprise from 2 to 10, from 2 to 8, or from 2 to 5 repeating units.

[0032] The solvent may be of high purity, in particular, the purity may be at least 98%, more specifically, at least 99%. The modifier should contain from about 30 to about 90% by weight of solvent to enable it to be applied to the solid core of the fertilizer particle. The solvent may be a single chemical component, but may also be a mixture of two or more glycols or glycol ethers.

[0033] The solvent may be anhydrous or contain a small amount of water, such as less than 2.0% by weight, less than 1.5% by weight, or less than 1.0% by weight. Water is undesirable because it can destroy the fertilizer particle by dissolving some of the nutrients contained in the fertilizer core and adversely affect some of the particle's physical properties, such as particle strength. However, anhydrous solvents can be significantly more expensive than solvents containing a small amount of water, such as less than 2.0% by weight, and the trade-off may be acceptable.

[0034] In one embodiment, the solvent comprises less than 2.0% by weight of water. In one embodiment, the solvent comprises less than 1.5% by weight of water.

[0035] In one embodiment, the solvent comprises less than 1.0% by weight of water.

[0036] The amount of solvent that can be used can depend on the micronutrient component selected for the modifier and the micronutrient loading desired for the nutritional effect. In one embodiment, the solvent can comprise from about 40 to about 80% by weight of the modifier. In particular, it can comprise from about 50 to about 80% by weight, or from 45 to 80% by weight, or from 40 to 85% by weight of the modifier. It was found that the fertilizer particles containing the modifier layer are free-flowing, which is important for their handling. In addition, the product showed good anti-caking properties, and its crushing strength was similar to the uncoated product. Anti-caking properties and crushing strength are important parameters for fertilizer particles that affect the stability of the particles during storage.

[0037] In one embodiment, the outer modifier layer may cover at least 50, 60, 70, 80, 90, 95, 96, 97, 98, or 99% of the core surface. In one embodiment, the modifier layer may cover 100% of the fertilizer particle surface.

[0038] In one embodiment, the modifier comprises urea. It was also surprisingly found that adding a small amount of urea to the modifier reduces the viscosity of such modifiers. When these modifiers are applied to solid particles, such as fertilizer particles, it is desirable that the modifier have a viscosity that ensures good and uniform coating. Several methods can be used to apply the modifier to the solid particles, for example, mixing in a mixer or in a coating device, such as a drum coater, spraying the modifier. In particular, the modifier can have a viscosity at 20 °C in the range of from about 0.005 to about 7 Pa⋅s (from 5 to 7000 cP), in particular in the range of from about 0.1 to about 5 Pa⋅s (from 100 to 5000 cP). If the spray method is used and the viscosity is too high, the liquid may be difficult to atomize and may block the spray equipment.Furthermore, the distribution of the resulting coating on the particles may be uneven due to its high viscosity. Since urea is a source of nutrients, adding urea to the modifier does not reduce the overall nutrient content of the fertilizer particles. Urea can be added in solid form and is readily soluble in an organic solvent. It can be dissolved in a small amount of solvent before mixing with the modifier. To ensure high quality of the final product, the coated fertilizer particles, urea must be very pure. In particular, the purity may be greater than 95%, in particular greater than 96%, in particular even greater than 97%, in particular even greater than 98%, in particular even greater than 99%. Urea may contain small amounts of water and / or biuret; in particular, it may contain less than 5% by weight of water or biuret, in particular less than 2% by weight of water or biuret.In one embodiment, the modifier comprises from about 0.1 to about 5.0% by weight of urea. In particular, it may comprise up to 2.0% by weight of urea.

[0039] In one embodiment, the solvent is selected from the group consisting of glycerin, also known as propan-1,2,3-triol or glycerol, monoethylene glycol, monopropylene glycol, diethylene glycol, 2-(2-ethoxyethoxy)-ethan-1-ol, also known as diethylene glycol monoethyl ether, and mixtures thereof. Glycerin, monoethylene glycol, monopropylene glycol, diethylene glycol, and 2-(2-ethoxyethoxy)-ethan-1-ol are well-known glycol-type solvents widely used in the chemical industry. They are well tolerated by plants, although some of these substances are classified as hazardous, such as monoethylene glycol and diethylene glycol. Glycerol and 2-(2-ethoxyethoxy)-ethan-1-ol have been found to be particularly suitable solvents for preparing liquid solutions with high concentrations of micronutrients, as glycerol and 2-(2-ethoxyethoxy)-ethan-1-ol are classified as nonhazardous substances. This reduces the risks to the user when handling the modifier.In one embodiment, the solvent is 2-(2-ethoxyethoxy)-ethan-1-ol. In one embodiment, the solvent is monoethylene glycol. In one embodiment, the solvent is glycerin.

[0040] In one embodiment, the modifier comprises at least 30 g / L of micronutrient, in particular at least 35 g / L of micronutrient, more particularly at least 40 g / L, even more particularly at least 44 g / L, and even more particularly at least 50 g / L of micronutrient. It has been found that in order to provide plants with a sufficiently high amount of micronutrients, the modifier should contain at least 30 g / L of micronutrient. A high micronutrient loading of the modifier allows the farmer or fertilizer supplier to apply a lower loading of the modifier to the fertilizer core. This is desirable, since a high loading can reduce the physical properties of the final product, such as anti-caking properties or strength properties. A high coating loading can also make the product sticky and create difficulties during storage, handling, and distribution in the field.

[0041] In one embodiment, the modifier comprises from 30 to 150 g / L of micronutrient, in particular from 35 to 150 g / L of micronutrient, more particularly from 40 to 150 g / L, even more particularly from 44 to 150 g / L, even more particularly from 50 to 150 g / L of micronutrient.

[0042] In one embodiment, the liquid composition comprises from 30 to 100 g / L of the micronutrient, in particular from 35 to 100 g / L of the micronutrient, more particularly from 40 to 100 g / L, even more particularly from 44 to 100 g / L, even more particularly from 50 to 100 g / L of the micronutrient.

[0043] This micronutrient is selected from a group consisting of boron, copper, manganese, molybdenum, and zinc. These elements are well-known and required in varying amounts by a wide range of crops.

[0044] In one embodiment, the micronutrient-containing component is a salt thereof or a complex of a micronutrient selected from the group consisting of boron, copper, manganese, molybdenum and zinc, wherein its salt or complex is soluble in the modifier solvent.

[0045] Elements such as boron, copper, manganese, molybdenum and zinc should be provided to plants in the form of ions such as Zn 2+ , Mn 2+ , Mn 3+ , Cu 4- , Cu 2+ , Mo 4+ or Mo 6+Plants cannot absorb neutral atoms. For each element, several sources are known, such as salts or complexes, suitable for agricultural application. A risk for metal ions such as copper, manganese, molybdenum, and zinc is that they react in the soil, for example, by oxidation, after application to the crop. Oxidation can occur due to oxygen in the air or oxidizing compounds or organisms, such as bacteria, present in the soil. Crops generally cannot absorb oxidized metals such as zinc oxide ZnO, copper(I) oxide or copper oxide Cu2O, copper(II) oxide or copper oxide CuO, manganese(II, III, IV, VI, VII) oxides, and molybdenum(IV or VI) oxides. Micronutrients can also react with phosphate ions present in the soil and form insoluble phosphate salts or complexes.Therefore, it is important that the micronutrient component be stable long enough after application to crops to allow them to be absorbed. Another risk is that the micronutrient source may react in the irrigation water, which can also make them unavailable to the crop. For example, under high pH conditions, copper, manganese, and zinc can precipitate as insoluble hydroxides or phosphates, leading to clogging of irrigation pipes and drippers.

[0046] In one embodiment, the micronutrient-containing compound is a chelate containing an element selected from the group consisting of copper, manganese, and zinc. Chelated compounds comprise an organic molecule, called a chelating agent, containing one or more chelating groups, such as an amine, a hydroxyl group, or a carboxylic acid. A metal chelate, such as copper, manganese, or zinc, is bound to the organic molecule via non-covalent bonds. Chelated compounds may contain additional ions other than the micronutrient to ensure their electroneutrality.

[0047] Chelated particles are generally more stable than other types of salts of the same metal, meaning the metal ion is protected or caged by the chelating agent, and this allows the metal to remain in its soluble, plant-available form, which is especially important for irrigation applications.

[0048] A well-known chelating agent is ethylenediaminetetraacetic acid, which forms ethylenediaminetetraacetate (EDTA) complexes with metals such as zinc, copper, manganese, and molybdenum. These EDTA complexes are commercially available and are typically among the cheapest chelates available. Examples of EDTA complexes include zinc disodium EDTA (ZnEDTA-Na2), zinc dipotassium EDTA (ZnEDTA-K2), copper disodium EDTA (CuEDTA-Na2), and manganese disodium EDTA (MnEDTA-Na2).

[0049] In one embodiment, the chelating agent in the chelate is an amino alcohol or an aminopolycarboxylic acid, in particular selected from the group consisting of ethylenediamine-N,N'-di-[(ortho-hydroxyphenyl)-acetic acid], ethylenediamine-N-[(ortho-hydroxyphenyl)-acetic acid]-N'-[(para-hydroxyphenyl)-acetic acid], ethylenediamine-N,N'-di-[ortho-hydroxy-methylphenyl]-acetic acid], ethylenediamine-N-[ortho-hydroxy-methylphenyl]-acetic acid]-N'-[(para-hydroxy-methylphenyl)-acetic acid] or N,N'-di-(2-hydroxybenzyl)-ethylenediamine-N,N'-disacetic acid, and mixtures thereof. Micronutrient chelates are available commercially as a wide range of compounds. Chelates containing an amino alcohol or aminopolycarboxylic acid have been found to be particularly suitable for this inoculant. They are generally non-toxic to plants and exhibit high solubility in a wide range of organic solvents, including glycol and glycol-ether solvents.Each of them is stable within a specific pH range. The chelating agent ensures that the micronutrient cation remains in a soluble form accessible to plants and is not oxidized to an oxide, which is insoluble in water and unavailable to plants.

[0050] According to one embodiment, the micronutrient-containing compound is selected from the group consisting of boric acid, sodium borate, sodium molybdate, and mixtures thereof. Boric acid, sodium borate, and sodium molybdate have been found to be soluble in polyhydric alcohols such as glycol, glycol ether, or mixtures thereof. These components are also known sources of boron and molybdenum, which are suitable for agricultural use. Boric acid, sodium borate, and sodium molybdate are also sufficiently soluble in water so that fertilizer particles coated with a (modifier) ​​conditioning agent containing one or more of boric acid, sodium borate, and sodium molybdate are completely soluble in water.

[0051] In one embodiment, a fertilizer particle includes a core and an outer layer of a modifier coating the core, wherein the modifier includes a compound containing boron; said compound is dissolved in a solvent; wherein

[0052] - the solvent is selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof;

[0053] - the solvent has a melting point below 15°C;

[0054] - the solvent constitutes from about 30 to about 90% by weight of the modifier;

[0055] - the modifier contains at least 30 g / l boron.

[0056] In one embodiment, the modifier comprises an antifoaming agent. One possible method for applying the modifier to solid particles involves spraying the modifier onto the particles. The particles may be in a rotating drum or lying on a substrate. When spraying a composition containing organic compounds, there is always a risk of foaming. Foaming occurs when air bubbles become trapped in the organic compound layer. To prevent this, an antifoaming agent can be added to the composition before spraying. A wide range of antifoaming agents is available from suppliers such as Synthron. The antifoaming agent is typically added in very small amounts, in particular from about 0.001 to about 1.0% by weight relative to the total composition, and does not affect the properties of the composition, except for its tendency to foam.

[0057] In one embodiment, the weight ratio of the micronutrient-containing compound to the solvent in the inoculant is in the range of 1:9 to 3:1, particularly in the range of 1:3 to 3:1. It is desirable to achieve an appropriate ratio of the micronutrient compound to the solvent. If the ratio is too high, the chelate may not be completely soluble in the solvent or the viscosity of the composition may become too high. This creates problems when applying the inoculant to the fertilizer particles. If the ratio is too low, the micronutrient concentration will be very low. To provide plants with sufficient micronutrients, it will be necessary to either apply more inoculant to the fertilizer particles, which may degrade the physical properties of the particles, or to increase the application rate of the particles, which increases the farmer's operating costs.Furthermore, other nutrients contained in the particles may be released in excess to crops, which can have a negative impact on the environment. For example, if too many nitrates or phosphates are released into the soil, these ions will not be retained properly and will leach into the environment. It has been found that the mass ratio of micronutrient compound to solvent in the inoculant can range from 1:9 to 3:1, specifically from 1:3 to 3:1.

[0058] In one embodiment of the invention, the modifier is substantially free of water. It may be desirable for the modifier to be substantially free of water, since water can impair physical properties such as particle strength and anti-caking properties of fertilizer particles. It may be difficult to obtain a completely anhydrous modifier, but the modifier may contain less than 5% by weight of water, in particular less than 2% by weight, more in particular less than 1% by weight, even more in particular less than 0.5% by weight. The components of the modifier, the solvent, the micronutrient-containing compound, and, optionally, urea, may contain a small amount of water, for example, less than 5% by weight of water. In particular, each of them may contain less than 2% by weight of water, in particular less than 1% by weight of water.

[0059] In one embodiment, the modifier comprises 0.1 to 2.0% by weight, in particular 0.1 to 1.0% by weight, of the fertilizer particle. It is important that the modifier be present in the fertilizer particles in the required amount. If the composition contains too little modifier, the amount of micronutrients delivered to crops will be insufficient for optimal yield. However, if the modifier content is too high, the overall nutrient content of the composition will be reduced: both the solvent and the ligand do not deliver nutrients to plants. Furthermore, the physical properties of the fertilizer particles, such as particle strength and adhesiveness, may be impaired by the large amount of solvent.

[0060] In one embodiment, the modifier does not contain any polymer other than the solvent. In other words, the modifier consists only of non-polymer components and a solvent, which may be polymeric. In one embodiment, the modifier does not contain any polymer with a molecular weight greater than 500 g / mol, greater than 600 g / mol, greater than 700 g / mol, greater than 800 g / mol, greater than 900 g / mol, or greater than 1000 g / mol. In one embodiment, the modifier does not contain any polymer with more than 10 repeating units. Polymers can have a very long shelf life in the environment, meaning they degrade very slowly. Regulations, particularly in Europe, limit the use of polymers in agricultural products to limit their environmental impact, so a polymer-free product, particularly one free of long-chain polymers, may be an advantage.Small polymers, such as those described as suitable solvents, may still be acceptable due to their low molecular weight, but polymers with long chains, particularly long chains consisting of carbon-carbon bonds, may be undesirable.

[0061] In one embodiment, the modifier consists solely of non-polymer components. Some solvents, such as monoethylene glycol and glycerin, are not polymers, and it may be advantageous to have only non-polymer components in the modifier.

[0062] In one embodiment, the core of the fertilizer particle includes a component selected from the group consisting of urea, ammonium salts, nitrate salts, phosphate salts, potassium salts, calcium nitrate, and mixtures thereof. It is desirable for the core of the fertilizer particle to contain a high percentage of plant-available nutrients. Urea, ammonium salts, and nitrate salts are three sources of nitrogen for plants; phosphate salts are the main source of phosphorus for plants; other cations, such as potassium and calcium, are also important plant nutrients. In one embodiment, the core of the fertilizer particle includes urea. In one embodiment, the fertilizer includes all three primary nutrients—N, P, and K. Such a fertilizer is called an NPK fertilizer.In addition to primary nutrients, the fertilizer particle core may include at least one source of one or more secondary nutrients (calcium, sulfur, magnesium) and micronutrients (boron, manganese, molybdenum, copper, and zinc). Sources of these elements suitable for agricultural use are well known in the art.

[0063] In one embodiment, the core of the fertilizer particle includes more than one component selected from the group consisting of urea, ammonium salts, nitrate salts, phosphate salts, potassium salts, calcium nitrate, and mixtures thereof. The fertilizer core may contain two components containing the same nutrient, such as urea and ammonium nitrate, or two components containing different nutrients, such as urea and ammonium sulfate.

[0064] In one embodiment, the modifier comprises from about 0.1 to about 10% by weight of urea based on the weight of the composition. It has been found that it is preferable for the modifier to contain from about 0.1 to about 10% by weight of urea based on the total composition of the modifier. If too little urea is used, the viscosity-lowering effect is not measurable. If too much urea is used, the micronutrient content decreases and may become too low for agricultural purposes. In particular, the modifier can contain from about 0.1 to about 5.0% by weight of urea based on the weight of the composition. More specifically, the modifier contains from about 0.1 to about 3.0% by weight of urea.

[0065] In one embodiment, the modifier comprises from 15 to 50% by weight of a CuEDTA complex, such as disodium CuEDTA or diammonium CuEDTA, from about 40 to about 80% by weight of monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0066] In one embodiment, the modifier comprises from 15 to 50% by weight of a ZnEDTA complex, such as disodium ZnEDTA or dipotassium ZnEDTA, from about 40 to about 80% by weight of monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0067] In one embodiment, the modifier comprises from 15 to 50% by weight of a MnEDTA complex, such as disodium MnEDTA, from about 40 to about 80% by weight of monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoam agent, and optionally from 0.1 to 5.0% by weight of urea.

[0068] In one embodiment, the modifier comprises from 15 to 50% by weight of a CuEDTA complex, such as disodium CuEDTA or diammonium CuEDTA, from about 40 to about 80% by weight of glycerin, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0069] In one embodiment, the modifier comprises from 15 to 50% by weight of a ZnEDTA complex, such as disodium ZnEDTA or dipotassium ZnEDTA, from about 40 to about 80% by weight of glycerin, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0070] In one embodiment, the modifier comprises from 15 to 50% by weight of a MnEDTA complex, such as disodium MnEDTA, from about 40 to about 80% by weight of glycerin, optionally from 0.01 to 1.0% by weight of an antifoam agent, and optionally from 0.1 to 5.0% by weight of urea.

[0071] In one embodiment, the modifier comprises from 15 to 50% by weight of boric acid, from about 40 to about 80% by weight of glycerin, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0072] In one embodiment, the modifier comprises from 15 to 50% by weight of sodium borate, from about 40 to about 80% by weight of glycerin, optionally from 0.01 to 1.0% by weight of an antifoam agent, and optionally from 0.1 to 5.0% by weight of urea.

[0073] In one embodiment, the modifier comprises from 15 to 50% by weight of sodium molybdate, from about 40 to about 80% by weight of glycerin, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0074] In one embodiment, the modifier comprises from 15 to 50% by weight of boric acid, from about 40 to about 80% by weight of monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoam agent, and optionally from 0.1 to 5.0% by weight of urea.

[0075] In one embodiment, the modifier comprises from 15 to 50% by weight of sodium borate, from about 40 to about 80% by weight of monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoam agent, and optionally from 0.1 to 5.0% by weight of urea.

[0076] In one embodiment, the modifier comprises from 15 to 50% by weight of sodium molybdate, from about 40 to about 80% by weight of monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoam agent, and optionally from 0.1 to 5.0% by weight of urea.

[0077] In one embodiment, the modifier comprises an acid. Specifically, the acid may be organic, i.e., a small molecule. Specifically, the acid may be a polycarboxylic acid, and more specifically, it may be selected from the group consisting of citric acid, malic acid, lactic acid, and mixtures thereof.

[0078] When the inoculant was applied to fertilizer particles containing an ammonium source, such as calcium ammonium nitrate, the particles were noted to emit a strong and unpleasant odor. After analysis with a Dräger tube, the odor was identified as ammonia. Without being bound by theory, it is believed that an element in the inoculant, such as a solvent or a chelated micronutrient compound, may exhibit a basic nature and catalyze the conversion of ammonium to ammonia. It has been found that adding an acidic component to the inoculant reduces this problem.A suitable acid must meet several criteria: sufficiently acidic to stop the release of ammonia, but not react or interact with other elements of the fertilizer and / or inoculant particles; preferably soluble in the solvent or solvent mixture used in the inoculant; preferably with a low health and safety risk to avoid complicating the application of the inoculant; commercially available at a reasonable cost; preferably available in pure form or in an anhydrous solvent, but it can be available as a hydrate complex. Malic, lactic, and citric acids have been found to be three chemicals that meet these criteria and are suitable for addition to the inoculant.Malic acid is a bis-carboxylic acid with pKa of 3.4 and 5.2, citric acid is a tri-carboxylic acid with pKa of 3.1, 4.8, and 6.4, and lactic acid is a mono-carboxylic acid with pKa of 3.9. Lowering the pH of the inoculant to approximately 7 or below may be beneficial to reduce ammonia release from the fertilizer particles. An inoculant supplemented with citric acid to adjust the pH to 7 has been shown to reduce ammonia release by approximately 50% compared to the same inoculant without citric acid and with a pH of 8.7. The pH of the inoculant can be maintained above 5. At pH below 5, the stability of the micronutrient compound, particularly when the compound is a chelate, may be compromised, and micronutrient atoms may precipitate and become unavailable to the plant. The modifier may contain from about 0.5 to about 10% by weight of acid. In particular, it may contain from about 0.5 to about 5% by weight.acid, more particularly from about 1 to about 5% by weight of the acid. In one embodiment, the pH of the modifier may be from 5.0 to 7.0.

[0079] In some embodiments, it was also observed that the addition of citric acid, in particular to a glycerin-containing modifier, reduced the viscosity of the modifier.

[0080] In one embodiment, the modifier comprises from 15 to 50% by weight of a micronutrient-containing compound, from about 40 to about 80% by weight of a solvent, in particular ethylene glycol or glycerin, from 0.1 to 5.0% by weight of urea and from 0.1 to 5.0% by weight of an acid, in particular citric acid.

[0081] In one embodiment, the fertilizer core contains from 0.1 to 2.0% by weight of water-insoluble material. The modifier is of interest for use on fertilizer particles for fertigation, which is a method in which fertilizer particles are dissolved in an aqueous solution, such as water, and supplied to the plant through an irrigation system. Fertigation is an effective method of fertilization because it provides the plant with nutrients at the right time in the right amount. Fertigation requires the use of high-purity fertilizer products that contain a small amount of water-insoluble material. An advantage of the modifier according to the present invention is that it can be completely water-soluble: glycol and glycol ethers generally have very good miscibility with water, and water-soluble micronutrient compounds, such as chelates, are well known.Thus, a fertilizer particle with a core containing 0.1 to 2.0% by weight of water-insoluble material and a modifier layer, as described herein, is an excellent fertilizer product for fertigation. Such particles can be produced in production facilities, with the coating variable to deliver different micronutrients, and then supplied to the farmer, who can directly add the particles to their fertigation tank to obtain a ready-to-use solution. Alternatively, to obtain the same nutrient solution from an uncoated fertilizer product, the farmer would need to purchase a separate micronutrient product or solution and measure out the required amount to add to the fertigation tank. Each of these steps carries risks, such as incompatibility of the micronutrient-containing product with the fertilizer particles and the risk of dosing errors.Thus, a fertilizer particle that combines a primary and / or secondary nutrient in its core with the required amount of micronutrients already applied as a coating on top of it is a very attractive product for farmers.

[0082] In one embodiment, the fertilizer particle containing the core and the modifier contains from 0.1 to 2.0% by weight of a water-insoluble material.

[0083] According to another aspect, a method for producing a fertilizer particle is proposed, wherein the fertilizer particle comprises a layer of a modifier containing a compound containing a micronutrient, comprising the steps of: (a) providing a fertilizer core particle; and (b) applying a modifier containing a compound containing a micronutrient dissolved in a solvent, wherein said solvent is selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof, and has a melting point below 15°C, said solvent constitutes from about 30 to about 90% by weight of the modifier, and said micronutrient is selected from the group consisting of boron, copper, manganese, molybdenum and zinc.

[0084] This aspect may exhibit the same or similar signs and technical results as the first aspect, and vice versa.

[0085] In another aspect, a method for producing a fertilizer particle according to the present invention is provided.

[0086] A number of well-established methods can be used to coat fertilizer particles with a liquid composition, such as spraying the composition onto particles on a conveyor or mixing the composition and particles in a rotating drum. Any coating method known in the art can be used in the present invention.

[0087] In one embodiment, the solvent is selected from the group consisting of glycerin, monoethylene glycol, monopropylene glycol, diethylene glycol, 2-(2-ethoxyethoxy)-ethan-1-ol, also known as diethylene glycol monoethyl ether, and mixtures thereof.

[0088] In one embodiment, the modifier comprises at least 30 g / L of micronutrient, in particular at least 35 g / L of micronutrient, more particularly at least 40 g / L, even more particularly at least 44 g / L, even more particularly at least 50 g / L of micronutrient.

[0089] In one embodiment, the modifier used in the method described above contains urea. Surprisingly, it was also found that adding a small amount of urea to the modifier reduces the viscosity of such modifiers.

[0090] In one embodiment, the modifier contains an antifoam agent. One possible method for applying the modifier to solid particles involves spraying them. The particles may be in a rotating drum or lying on a substrate. When spraying a composition containing organic compounds, there is always a risk of foaming. Foam occurs when air bubbles become trapped in the organic compound layer. To prevent this, an antifoam agent can be added to the composition before spraying. A wide range of antifoam agents is available from suppliers such as Synthron. The antifoam agent is typically added in very small quantities, typically less than 1.0% by weight of the total composition, and does not affect the properties of the composition, except for its tendency to foam.

[0091] In one embodiment, the modifier comprises an acid. Specifically, the acid may be organic, i.e., a small molecule. Specifically, the acid may be a polycarboxylic acid, and more specifically, it may be selected from the group consisting of citric acid, malic acid, and mixtures thereof.

[0092] In one embodiment, the modifier comprises from 0.1 to 2% by weight, in particular from 0.1 to 1.0% by weight of the fertilizer particle.

[0093] In another aspect, a liquid composition is provided, comprising a compound containing a micronutrient, dissolved in a solvent, wherein the solvent is selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof, and has a melting point below 15°C, the solvent constitutes from about 30 to about 90% by weight of the liquid composition, and the micronutrient is selected from the group consisting of boron, copper, manganese, molybdenum and zinc. This aspect can exhibit the same or similar features and technical results as the first aspect, and vice versa.

[0094] The above composition can be used to coat fertilizer particles to provide the particles with a source of micronutrients. Surprisingly, it was found that adding a small amount of urea to the previously described compositions reduces the viscosity of such compositions. When these compositions are applied to solid particles, such as fertilizer particles, it is desirable for the liquid composition to have an appropriate viscosity to ensure uniform coating.

[0095] In one embodiment, the solvent in the liquid composition is selected from the group consisting of glycerin, monoethylene glycol, monopropylene glycol, diethylene glycol, 2-(2-ethoxyethoxy)-ethan-1-ol, also known as diethylene glycol monoethyl ether, and mixtures thereof. Several examples of glycols and glycol ethers have been identified that are particularly suitable for preparing a composition with a micronutrient compound, in particular a micronutrient chelate, and optionally urea. Glycerin and diethylene glycol monoethyl ether are classified as non-hazardous substances, making them particularly suitable as a solvent.

[0096] In one embodiment, the liquid composition comprises from about 0.1 to about 10% by weight of urea based on the weight of the composition. It has been found that an amount of urea from about 1.0 to about 10% by weight of the total liquid composition is preferable. If too much urea is used, the micronutrient content decreases and becomes too low for agricultural purposes. In particular, the liquid composition can contain from about 0.1 to about 5.0% by weight of urea, more specifically, from about 0.1 to about 2.0% by weight of urea.

[0097] In one embodiment, the weight ratio of the micronutrient-containing compound to the solvent is in the range of 1:9 to 3:1, in particular in the range of 1:3 to 3:1, and more specifically in the range of 1:2 to 2:1. The ratio of the micronutrient to the solvent should be optimized to obtain a composition with the desired characteristics. The composition should have an appropriate viscosity so that it can be applied to solid particles, and the micronutrient content should be high enough to provide plants with a sufficient amount of micronutrients with a minimum number of applications.

[0098] In one embodiment, the liquid composition comprises at least 30 g / L of micronutrient, in particular at least 35 g / L of micronutrient, more particularly at least 40 g / L, even more particularly at least 44 g / L, even more particularly at least 50 g / L, even more particularly at least 55 g / L of micronutrient. The advantage of the proposed liquid composition is that a high concentration of micronutrient can be achieved while maintaining a viscosity suitable for application as a coating for solid fertilizer particles.

[0099] In one embodiment of the invention, the liquid composition contains from 30 to 200 g / L, from 35 to 200 g / L, from 40 to 200 g / L, from 44 to 200 g / L, from 50 to 200 g / L, or from 55 to 200 g / L of the micronutrient.

[0100] In one embodiment, the liquid composition comprises from 30 to 150 g / L, from 35 to 150 g / L, from 40 to 150 g / L, from 44 to 150 g / L, from 50 to 150 g / L, or from 55 to 150 g / L of the micronutrient.

[0101] It has been discovered that very high concentrations of micronutrients can be obtained, particularly when the micronutrient is boron or molybdenum. In one embodiment, the liquid composition comprises from 30 to 200 g / L, from 35 to 200 g / L, from 40 to 200 g / L, from 44 to 200 g / L, from 50 to 200 g / L, or from 55 to 200 g / L of boron or molybdenum.

[0102] In one embodiment, the liquid composition comprises from 30 to 150 g / L, from 35 to 150 g / L, from 40 to 150 g / L, from 44 to 150 g / L, from 50 to 150 g / L, or from 55 to 150 g / L of boron or molybdenum.

[0103] In one embodiment, the liquid composition comprises from 90 to 150 g / L, from 90 to 140 g / L, from 90 to 130 g / L, or from 90 to 120 g / L of molybdenum. With molybdenum as a micronutrient, and in particular when using sodium molybdate as a molybdenum source, it has been found that stable compositions with very high concentrations of the micronutrient can be obtained.

[0104] In one embodiment, the sum of two or more micronutrients is from 30 to 150 g / L, from 35 to 150 g / L, from 40 to 150 g / L, from 44 to 150 g / L, from 50 to 150 g / L, or from 55 to 150 g / L. For example, a composition containing two or more micronutrients can be obtained, in which the sum of the concentration of micronutrients is at least 30 g / L or even 50 g / L. In one embodiment, the liquid composition contains manganese, copper and zinc, and the combined concentration of micronutrients is more than 50 g / L, or from 50 to 200 g / L, or from 50 to 150 g / L, or from 50 to 100 g / L.

[0105] In one embodiment, the liquid composition comprises an antifoaming agent.

[0106] In one embodiment, the liquid composition comprises an acid. Specifically, the acid may be organic, i.e., a small molecule. Specifically, the acid may be a polycarboxylic acid, and more specifically, it may be selected from the group consisting of citric acid, malic acid, and mixtures thereof.

[0107] In one embodiment, the liquid composition has a pH of 5.0 to 9.0, or 5.0 to 8.0, or 5.0 to 7.5.

[0108] In one embodiment, the liquid composition comprises from 15 to 50% by weight of a component containing boron, from about 40 to about 80% by weight of glycerin or monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0109] In one embodiment, the liquid composition comprises from 15 to 50% by weight of a component containing molybdenum, from about 40 to about 80% by weight of glycerin or monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0110] In one embodiment, the liquid composition comprises from 15 to 50% by weight of boric acid or sodium borate, from about 40 to about 80% by weight of glycerin or monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0111] In one embodiment, the liquid composition comprises from 15 to 50% by weight of sodium molybdate, from about 40 to about 80% by weight of glycerin or monoethylene glycol, optionally from 0.01 to 1.0% by weight of an antifoaming agent, and optionally from 0.1 to 5.0% by weight of urea.

[0112] According to another aspect, the use of a composition as a coating agent for fertilizer particles is proposed, wherein the composition comprises a compound containing a micronutrient selected from the group consisting of boron, copper, manganese, molybdenum and zinc, dissolved in a solvent selected from the group consisting of polyhydric alcohols, derivatives of polyhydric alcohols and mixtures thereof, and having a melting point below 15°C, and optionally urea. This aspect may exhibit the same or similar features and technical results as the first aspect, and vice versa.

[0113] In one embodiment, the composition comprises an antifoaming agent.

[0114] In one embodiment, the composition comprises an acid. Specifically, the acid may be organic, i.e., a small molecule. Specifically, the acid may be a polycarboxylic acid, and more specifically, it may be selected from the group consisting of citric acid, malic acid, lactic acid, and mixtures thereof. In one embodiment, the composition has a pH of 5.0 to 7.0.

[0115] In another aspect, the use of the composition as described above as a coating agent for fertilizer particles is disclosed.

[0116] The invention will now be described with reference to the following examples.

[0117] Example 1

[0118] The following example shows the composition required to prepare 1 kg of liquid copper chelate composition based on disodium copper EDTA, g:

[0119] Disodium CuEDTA (15% w / w Cu) 250.0

[0120] Monoethylene glycol 750.0

[0121] Total 1000.0

[0122] The solvent was placed in a glass vessel equipped with a paddle stirrer. Copper chelate powder was slowly added to the stirred solvent, controlling the addition rate to avoid clumping. After complete addition, stirring was continued for 120 minutes to ensure complete dissolution. The method can be carried out at room temperature, or, alternatively, the solvent / mixture can be heated to 30-40°C to accelerate dissolution.

[0123] The resulting product was a transparent, bright blue, slightly viscous solution with the following physicochemical characteristics:

[0124] Density: 1.217 kg / L at 20°C

[0125] Viscosity (Brookfield, Spindle 3, 12 rpm)<200 cP at 20°C

[0126] Copper content: 3.65% w / w (=44g / L)

[0127] The product remained stable for at least 12 weeks when stored at room temperature.

[0128] Example 2

[0129] The following example shows the composition required to prepare 1 kg of liquid copper chelate composition based on disodium copper EDTA, g:

[0130] Disodium CuEDTA (15% w / w Cu) 250.0

[0131] glycerin 750

[0132] Total 1000.0

[0133] The product was prepared similarly to example 1.

[0134] The resulting product was a transparent, bright blue, slightly viscous solution with the following physicochemical characteristics:

[0135] Density: 1.351 kg / L at 20°C

[0136] Viscosity (Brookfield, spindle 3, 12 rpm) 6700 cP at 20°C

[0137] Copper content: 3.65% w / w (=49g / L)

[0138] The product remained stable for 12 weeks when stored at room temperature.

[0139] Example 3

[0140] The following example shows the composition required to prepare 1 kg of liquid zinc chelate composition based on disodium zinc EDTA, g:

[0141] Disodium ZnEDTA (15% w / w Zn) 250.0

[0142] Monoethylene glycol 750.0

[0143] Total 1000.0

[0144] The product was prepared similarly to example 1.

[0145] The resulting product was a transparent, colorless, slightly viscous solution with the following physicochemical characteristics:

[0146] Density: 1.232 kg / L at 20°C

[0147] Viscosity (Brookfield, spindle 3, 12 rpm) <200 cP at 20°C pH 6.8

[0148] Zn content: 3.7% w / w (=46g / L)

[0149] The product remained stable for 12 weeks when stored at room temperature.

[0150] Example 4

[0151] The following example shows the composition required to prepare 1 kg of liquid copper chelate composition based on disodium copper EDTA, g:

[0152] Disodium CuEDTA (15% w / w Cu) 250.0

[0153] Monoethylene glycol 742.5

[0154] Citric acid 7.5

[0155] Total 1000.0g

[0156] The product was prepared similarly to example 1.

[0157] The resulting product was a transparent, bright blue, slightly viscous solution with the following physicochemical characteristics:

[0158] Density: 1.272 kg / L at 20°C

[0159] Viscosity (Brookfield, Spindle 3, 12 rpm) 3240 cP at 20°C

[0160] Zn content: 3.65% w / w (=49g / L)

[0161] The product remained stable for 12 weeks when stored at room temperature.

[0162] Example 5

[0163] The following example shows the composition required to prepare 1 kg of liquid manganese chelate composition, g:

[0164] Disodium MnEDTA (13% w / w Mn) 250.0

[0165] Monoethylene glycol 750.0

[0166] Total 1000.0

[0167] The product was prepared similarly to example 1.

[0168] The resulting product was a transparent, dark pink, slightly viscous solution with the following physicochemical characteristics:

[0169] Density: 1.209 kg / L at 20°C

[0170] Viscosity (Brookfield, spindle 3, 12 rpm)<200 cP at 20°C

[0171] Mn content: 3.20% w / w (=39 g / L)

[0172] pH 6.6

[0173] The product remained stable for 12 weeks when stored at room temperature.

[0174] Example 6

[0175] The following example shows the composition required to prepare 1 kg of liquid manganese chelate composition, g:

[0176] Disodium MnEDTA (13% w / w Mn) 250.0

[0177] Monoethylene glycol 742.5

[0178] Urea 7.5

[0179] Total 1000.0

[0180] The solvent was placed in a glass vessel under a Silverson high-shear rotor-stator stirrer. Stirring was started and the manganese chelate powder was slowly added to the mixed solvent, controlling the addition rate to avoid clumping. After complete addition, stirring was continued for 9 minutes to ensure complete dissolution.

[0181] The resulting product was a transparent, dark pink, slightly viscous solution with the following physicochemical characteristics:

[0182] Density: 1.210 kg / L at 20°C

[0183] Viscosity (Brookfield, Spindle 3, 12 rpm) <200 cP at 20°C

[0184] Mn content: 3.20% w / w (=39 g / L)

[0185] pH 6.6

[0186] Example 7

[0187] The following example shows the composition required to prepare 1 kg of liquid composition containing boric acid, g:

[0188] Boric acid 250.0

[0189] Glycerin 750.0

[0190] Total 1000.0

[0191] Boric acid is a powder. To facilitate its dissolution, it may be advantageous to grind the powder to reduce particle size. The powder can be ground by hand.

[0192] Alternatively, a Silverson high shear rotor-stator mixer may be used as described in Example 6.

[0193] The resulting product was a transparent, colorless, slightly viscous solution with the following physicochemical characteristics:

[0194] Density: 1.268 kg / L at 20°C

[0195] Viscosity (Brookfield, spindle 3, 12 rpm) 400 cP at 20°C

[0196] B content: 4.40% w / w (=56g / L)

[0197] pH 1.9.

[0198] Example 8

[0199] The following example shows the composition required to prepare 1 kg of a liquid composition containing boric acid and urea, g:

[0200] Boric acid 250.0

[0201] Glycerin 742.5

[0202] Urea: 7.5

[0203] Total 1000.0

[0204] The resulting product was a transparent, colorless, slightly viscous solution with the following physicochemical characteristics:

[0205] Density: 1.275 kg / L at 20°C

[0206] Viscosity (Brookfield, spindle 3, 12 rpm) 360 cP at 20°C

[0207] B content: 4.40% w / w (=56g / L)

[0208] pH 2.2

[0209] Adding 0.75% by weight of urea results in a 10% decrease in the viscosity of the solution compared to Example 7.

[0210] Example 9

[0211] The following example shows the composition required to prepare 1 kg of a liquid composition containing sodium molybdate, g:

[0212] Sodium molybdate 250.0

[0213] Monoethylene glycol 750.0

[0214] Total 1000.0

[0215] The resulting product was a transparent, slightly viscous solution with the following physicochemical characteristics:

[0216] Density: 1.270 kg / L at 20°C

[0217] Viscosity (Brookfield, Spindle 3, 12 rpm) <200 cP at 20°C

[0218] Mo content: 10% w / w (=127g / L).

[0219] Example 10

[0220] The following example shows the composition required to prepare 1 kg of a liquid composition containing dipotassium zinc EDTA, g:

[0221] Dipotassium-ZnEDTA (14.5 wt / wt Zn) 250.0

[0222] Monoethylene glycol 750.0

[0223] Total 1000.0

[0224] The resulting product was a transparent, slightly viscous solution with the following physicochemical characteristics:

[0225] Density: 1.217 kg / L at 20°C

[0226] Viscosity (Brookfield, Spindle 3, 12 rpm) <200 cP at 20°C

[0227] Zn content: 3.7% w / w (=45g / L).

[0228] Example 11

[0229] The following example shows the composition required to prepare 1 kg of a liquid composition containing a mixture of chelated elements Mn, Zn and Cu, g:

[0230] Disodium MpEDTA (13% w / w Mn) 100.0

[0231] Disodium ZnEDTA (15% w / w Zn) 100.0

[0232] Disodium CuEDTA (15% w / w Cu) 100.0

[0233] Glycerin 700.0

[0234] Total 1000.0

[0235] The resulting product was a transparent, bright blue, slightly viscous solution with the following physicochemical characteristics:

[0236] Density: 1.354 kg / L at 20°C

[0237] Viscosity (Brookfield, spindle 3.12 rpm) 9880 cP at 20°C

[0238] Mn content: 1.30% w / w (=17.6 g / L)

[0239] Zn content: 1.50% w / w (=20.0g / L)

[0240] Cu content: 1.50% w / w (=20.0g / L)

[0241] pH 7.4.

[0242] Example 12

[0243] The following example shows the composition required to prepare 1 kg of a liquid composition containing copper chelate and a solvent mixture, g:

[0244] Glycerin 375

[0245] MEG 375

[0246] Disodium CuEDTA (15% w / w Cu) 250

[0247] Total 1000.0

[0248] The resulting product was a transparent, bright blue, slightly viscous solution with the following physicochemical characteristics:

[0249] Density: 1.305 kg / L at 20°C

[0250] Viscosity (Brookfield, Spindle 3, 12 rpm) >10000 cP at 20°C

[0251] Copper content: 3.70% w / w (=48.3g / L)

[0252] pH 6.8.

[0253] Example 13

[0254] The following example shows the composition required to prepare 1 kg of a liquid composition containing sodium molybdate and a solvent mixture, g:

[0255] Glycerin 375

[0256] MEG 375

[0257] Sodium molybdate 300

[0258] Total 1000.0

[0259] The resulting product was a transparent, colorless, slightly viscous solution with the following physicochemical characteristics:

[0260] Density: 1.350 kg / L at 20°C

[0261] Viscosity (Brookfield, Spindle 3, 12 rpm) >10000 cP at 20°C

[0262] Mo content: 10.00% w / w (=135.0g / L)

[0263] pH 6.8.

[0264] Example 14

[0265] Tests were conducted to evaluate the effect of the copper chelate composition described above on the quality parameters of fertilizers when applied to solid fertilizer particles. For comparison, a water-based copper chelate solution was prepared and tested. The crushing strength (crushing strength, hardness) of fertilizer granules / spherical particles is an important property used in quality control of fertilizer production. Crushing strength is one of the key parameters for assessing the physical properties of fertilizers and is significantly dependent on the free water content of the fertilizer.

[0266] Each of the copper chelate compositions was applied to NPK particles containing at least 98.5% by weight of water-soluble material at an amount equivalent to 4 liters per ton (equivalent to approximately 0.50% by weight of the final product) using a laboratory-scale conical blender. 1 kg of NPK particles was added to the blender, and an appropriate amount of the copper chelate composition was added to the fertilizer as it was mixed in the rotating blender. Mixing was continued for 20 seconds after addition to ensure thorough distribution and application of the copper chelate composition on top of the urea. The treatment was carried out as follows:

[0267] 1. Control - Untreated

[0268] 2.4 L / mt water-based copper chelate composition (25 wt% disodium CuEDTA containing 15 wt% Cu)

[0269] 3.4 L / mt non-aqueous composition of copper chelate dissolved in monoethylene glycol (25 wt% disodium CuEDTA containing 15 wt% Cu and 75 wt% monoethylene glycol)

[0270] 4. 4 L / mt non-aqueous composition containing copper EDTA and urea dissolved in glycerin (25 wt% disodium CuEDTA containing 15 wt% Cu, 10 wt% urea and 75 wt% glycerin)

[0271] 5. 4 L / mt of non-aqueous composition containing copper EDTA and urea dissolved in monoethylene glycol (25 wt% disodium CuEDTA containing 15 wt% Cu, 10 wt% urea and 75 wt% monoethylene glycol) "mt" is an abbreviation for the unit metric ton.

[0272] The coated particles were packed into bags, sealed and stored for 24 hours at 50°C, and then the crushing strength of the granules was measured using a Mecmesin DT10 hardness tester according to the following method.

[0273] A single pellet was placed on a smooth, hard surface (a laboratory benchtop), and the plunger of the tester was positioned over the pellet. The tester was depressed until the pellet disintegrated, and the scale reading was noted.

[0274] The test was conducted at room temperature (approx. 20°C), repeated 20 times for each treatment, and the average value was indicated in the table below.

[0275]

[0276]

[0277] The results clearly show that the composition according to the present invention has less effect on the strength of fertilizer granules than the water-containing composition.

[0278] The coated particles were also subjected to a caking test, in which a 1 kg plate was placed on top of the bag of particles. After two weeks at 50°C, none of the particles with test numbers 3 through 6 showed caking.

Claims

1. A fertilizer particle comprising a core and an outer layer of a modifier covering the core, wherein the modifier comprises a compound containing a micronutrient, said compound being completely dissolved in a solvent, wherein - the solvent is selected from the group consisting of glycerol, monoethylene glycol, monopropylene glycol, diethylene glycol, 2-(2-ethoxyethoxy)-ethan-1-ol, also known as diethylene glycol monoethyl ether, and mixtures thereof; - the solvent has a melting point below 15°C; - the solvent makes up from 30 to 90% of the modifier by weight; - the modifier contains at least 30 g / l of a micronutrient selected from the group consisting of copper, manganese, molybdenum and zinc; - the micronutrient-containing compound is a molybdenum salt or an ethylenediaminetetraacetate chelate of copper, manganese, or zinc; and - the modifier has a pH from 5.0 to 7.

0.

2. A fertilizer particle according to paragraph 1, characterized in that the modifier contains an acid.

3. A fertilizer particle according to claim 1 or 2, characterized in that the acid is selected from the group consisting of citric acid, malic acid, lactic acid and mixtures thereof.

4. A fertilizer particle according to any one of paragraphs 1-3, characterized in that the modifier contains urea.

5. A fertilizer particle according to any one of paragraphs 1-4, characterized in that the compound containing the micronutrient is sodium molybdate.

6. A fertilizer particle according to any one of claims 1 to 5, characterized in that the modifier contains at least 35 g / l of a micronutrient selected from the group consisting of copper, manganese, molybdenum and zinc, in particular at least 40 g / l, even more particularly at least 44 g / l, even more particularly at least 50 g / l of a micronutrient.

7. A fertilizer particle according to any one of paragraphs 1-6, characterized in that the mass ratio of the compound containing the micronutrient to the solvent in the modifier is in the range from 1:9 to 3:1, in particular in the range from 1:3 to 3:

1.

8. A fertilizer particle according to any one of paragraphs 1-7, characterized in that the modifier constitutes from 0.1 to 2.0% by weight, in particular from 0.1 to 1.0% by weight, of the fertilizer particle.

9. A fertilizer particle according to any one of paragraphs 1-8, characterized in that the core of the fertilizer particle contains a component selected from the group consisting of urea, ammonium salts, nitrate salts, phosphate salts, potassium salts, calcium nitrate and mixtures thereof.

10. A fertilizer particle according to any one of paragraphs 1-9, characterized in that the core of the fertilizer particle contains from 0.1 to 2.0% by weight of water-insoluble material.

11. A method for producing a fertilizer particle according to any one of paragraphs 1-10, comprising the steps of: a. obtaining the core of the fertilizer particle; b. applying a modifier comprising a compound containing a micronutrient completely dissolved in a solvent, wherein said solvent is selected from the group consisting of glycerol, monoethylene glycol, monopropylene glycol, diethylene glycol, 2-(2-ethoxyethoxy)-ethan-1-ol, also known as diethylene glycol monoethyl ether, and mixtures thereof, said solvent has a melting point below 15°C, said solvent constitutes from 30 to 90% by weight of the modifier, said modifier contains at least 30 g / l of a micronutrient, said micronutrient is selected from the group consisting of copper, manganese, molybdenum and zinc, said compound containing the micronutrient is a molybdenum salt or an ethylenediaminetetraacetate chelate of copper, manganese or zinc and said modifier has a pH from 5.0 to 7.0.

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