A process of preparing a fertilizer composition

Abstract

The present invention relates to the field of agricultural compositions, particularly fertilizer compositions. In particular, the present invention relates to a process of preparing an agricultural fertilizer composition comprising a nutrient particle, preferably a plant nutrient, and natural ingredients such as one or more plant extracts, a weak acid, an amino acid or a source of amino acid and a stabilizer. The present invention also relates to an energy efficient and a simple / linear process of preparing a stable and homogenous agricultural fertilizer composition.

Description

[0001] “A PROCESS OF PREPARING A FERTILIZER COMPOSITION”

[0002] FIELD OF THE INVENTION

[0003] The present invention relates in general to the field of agricultural compositions, particularly fertilizer compositions. In particular, the present invention relates to a process of preparing an agricultural fertilizer composition comprising a nutrient particle, preferably a plant nutrient, and natural ingredients such as one or more plant extracts, a weak acid, an amino acid or a source of amino acid and a stabilizer. The present invention also relates to an energy efficient and a simple / linear process of preparing a stable and homogenous agricultural fertilizer composition.

[0004] BACKGROUND

[0005] Nanoparticle compositions comprising plant growth promoters such as nitrogen, phosphorus and / or potassium when used as fertilizers offer benefits in nutrition management through their strong potential to increase nutrient use efficiency. Nutrients in nanoparticle compositions release nutrients very slowly as compared to conventional fertilizers both in soil when applied as broadcast or in solution when applied as foliar spray. This approach not only increases nutrient-use efficiency, but also minimizes nutrient leaching into ground water. The application of nano-fertilizers is a valuable alternative approach in agriculture due to its potential for reducing the application of mineral nitrogen fertilizers and increasing or maintain the same yield quality and quantity, thereby helping to reduce the worldwide food shortage. However, with only synthetic chemical nanoparticle compositions being available for use, it does not mitigate the risk to the environment to a large extent as chemical exposure is continued when it is manufactured and applied.

[0006] Also, preparing stable and homogenous nanoparticle compositions is a challenge and most present processes and products exhibit limited or no stability in terms of controlled solubilization, homogeneity, pH levels, active ingredient and so on. Moreover, most processes involve a chemical process of preparing nanoparticle compositions.

[0007] Zeta potential is a measure of the effective electric charge on the nanoparticle's surface, quantifying the charges. When a nanoparticle has a net surface charge, the charge is screened by the concentration of ions of opposite charge near the nanoparticle surface. Zeta potential (negative or positive) indicates that there is enough double layer repulsion effect between the particles, which prevents their aggregation. A solution displaying favorable zeta potential (negative or positive) is desirable as it is considered stable and averse to aggregation, thus, maintaining the homogeneity of the solution.

[0008] Thus, there is a need for novel and efficient processes to prepare stable and homogenous fertilizer compositions of plant nutrients, particularly nanoparticle compositions. There is a need for efficient and simple processes involving safe ingredients not harmful to plants, environment and nature. There is a need in the art to identify efficient green synthesis process to prepare the said compositions.

[0009] Therefore, it is an object of the present invention to provide an efficient process to prepare stable and homogenous agricultural fertilizer compositions of plant nutrients, particularly nanoparticle compositions. It is also an object of the present invention to provide a stable and homogenous agricultural fertilizer composition comprising nutrient particles comprising nitrogen, phosphorous, potassium, or combinations thereof, with particle size in the nanoparticle range. It is another object of the present invention to provide a process of preparing a stable and homogenous agricultural fertilizer composition comprising nutrient particles comprising nitrogen, phosphorous, potassium, or combinations thereof, using environment friendly and plant beneficial components, such as plant extracts.

[0010] SUMMARY

[0011] An embodiment of the present invention provides a process of preparing an agricultural fertilizer composition, said method comprising:

[0012] A. providing a homogenous solution of a plant extract;

[0013] B. solubilizing in the homogenous solution of the plant extract a weak acid;

[0014] C. adding a stabilizer to the solution of step B and solubilizing to obtain a homogenous solution;

[0015] D. adding and solubilizing an amino acid or an amino acid source to homogenous solution obtained in step C; and

[0016] E. mixing the raw material form of a nutrient particle, or a plurality of raw material forms of nutrient particles in the homogenous solution obtained in step D to obtain a final composition, wherein the nutrient particle or the plurality of nutrient particles is / are a plant nutrient selected from nitrogen, its compounds or salts; phosphorus, its compounds or salts; potassium, its compounds or salts; or combinations thereof.

[0017] In an embodiment, the final composition obtained has a zeta potential in the range of about +20 mV to about -20 mV.

[0018] In an embodiment, the particle size of resultant particles or nutrient particles or plurality of nutrient particles present in the composition ranges from about 1 nm to about 5,000 nm.

[0019] In an embodiment, the process of the present invention is characterized by absence of energy expenditure, particularly, involvement of heat. The process is characterized by absence of heating and cooling steps for homogenous solubilization of the raw material form of nutrient particle or a plurality of nutrient particles. Thus, in an embodiment, the process of the present invention is energy efficient and time efficient process.

[0020] In an embodiment, said process further comprises adding a humic substance along with the amino acid or the amino acid source.

[0021] In an embodiment, said process further comprises adding an additional stabilizing agent(s) to the final composition. In an embodiment, said additional stabilizing agent(s) comprise a pH stabilizer. In an embodiment, the pH stabilizer is the only additional stabilizing agent or additional stabilizing agent(s) comprise one or more agent(s) in addition to the pH stabilizer.In an embodiment, said process comprises adding a pH stabilizer to the final composition.

[0022] In an embodiment, said process further comprises adding an agriculturally acceptable excipient to the final composition.

[0023] An aspect of the present invention also provides an agricultural fertilizer composition obtainable by the process described by the present invention.

[0024] An aspect of the present invention provides an agricultural fertilizer composition comprising: a) a plant extract; b) a weak acid; c) a stabilizer; d) an amino acid source; and e) a nutrient particle or a plurality of nutrient particles, wherein the nutrient particle is a plant nutrient selected from nitrogen, its compounds or salts; phosphorus, its compounds or salts; potassium, its compounds or salts; or combinations thereof.

[0025] An aspect of the present invention provides an agricultural composition comprising: a) a nutrient particle or a plurality of nutrient particles, wherein the nutrient particle is a plant nutrient, selected from nitrogen, its compounds or salts; phosphorus, its compounds or salts; potassium, its compounds or salts; or combinations thereof; b) a plant extract; c) a stabilizer; d) a weak acid; e) an amino acid or an amino acid source; f) optionally, a humic substance selected from humic acid, fulvic acid, or combinations thereof; g) optionally, an additional stabilizing agent; and h) optionally, an agriculturally acceptable excipient.

[0026] In an embodiment, said composition is a nanoparticle composition. In an embodiment, said composition is a nanoparticle fertilizer composition. In an embodiment, said composition is a biofertilizer.

[0027] An aspect of the present invention provides a method of growth stimulation in a plant or a part thereof, wherein the method comprises applying to the plant, a part thereof, or a locus a composition obtained by the process of the present invention.

[0028] An aspect of the present invention provides a method of improving plant health and yield comprising applying an agricultural composition of the present invention to a plant or a part thereof, or a locus.

[0029] DETAILED DESCRIPTION

[0030] For the purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of materials / ingredients used in the specification are to be understood as being modified in all instances by the term "about".

[0031] As used herein, the term "about" refers to a measurable value such as a parameter, an amount, a temporal duration, and the like and is meant to include variations of + / -10% or less, specifically variations of + / -5% or less, more specifically variations of + / -1% or less, and even more specifically variations of + / -0.1% or less of and from the particularly recited value, in so far as such variations are appropriate to perform in the disclosure described herein. Furthermore, it is also to be understood that the value to which the modifier "about" refers is itself specifically disclosed herein.

[0032] Recitation of ranges of values are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. The endpoints of all ranges are included within the range and independently combinable. As used herein, all numerical values or numerical ranges include integers within such ranges and fractions of the values or the integers within ranges unless the context clearly indicates otherwise. Thus, for example, reference to a range of 90-100%, includes 91%, 92%, 93%, 94%, 95%, 95%, 97%, etc., as well as 91.1%, 91.2%, 91.3%, 91.4%, 91.5%, etc., 92.1%, 92.2%, 92.3%, 92.4%, 92.5%, etc., and so forth. All methods described herein can be performed in a suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.

[0033] Thus, before describing the present invention in detail, it is to be understood that this invention is not limited to particularly exemplified process parameters or composition that may of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the scope of the invention in any manner. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various embodiments given in this specification. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the case of conflict, the present document, including definitions will control. It must be noted that, as used in this specification, the singular forms “a,” “an” and “the” include plural referents unless the content clearly dictates otherwise. The terms “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances.

[0034] As used herein, the terms “comprising” “including,” “having,” “containing,” “involving,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to.

[0035] The term “particle” as used herein refers to any compound, molecule, atom, ion of any constituent, substance, composition, mixture, or components thereof used, applied or employed in the context of the present invention. Said term encompasses any liquid or solid forms and can refer to standalone molecules; atoms; ions such as anions, cations, Zwitterions; complexes; composites; conjugates; chelates; encapsulated forms; microcrystalline forms, etc.

[0036] The term “nutrient particle” refers to a particle defined herein comprising a plant growth promoting nutrient such as nitrogen, phosphorus, potassium, or combinations thereof. The particle may be an organic particle, an inorganic particle, or a complex of both. The term also refers to a complex comprising atleast one particle comprising a nitrogen atom, a phosphorus atom, a potassium atom, or combinations thereof. The term “a nutrient particle” encompasses a plurality of nutrient particles or a plurality of nutrient nanoparticles.

[0037] The term “resultant particle” or “resultant particles” refers to the particles present in the final composition. Such resultant particles may comprise individual components or aggregates of any or all components present in the final composition or added to make the composition. For example, a process of adding A,B,C,D components will result into a final composition comprising resultant particles which may be A, B, C, D, AB, AC, AD, BC, BD, CD, ABC, ABD, BCD, and / or ABCD. The resultant particles may also comprise components arising out of physical or chemical interactions between the components added together to make the final composition, wherein these components may be separate or a part of aggregates of any or all components present in the final composition or added to make the final composition.

[0038] The term “composition” in the present specification refers to a final composition resulting as a process of adding together or one after the other more than one component.

[0039] The term “nanoparticle” refers to an ultrafine particle having a nanometric size ranging between 0.1 nm to 5000 nm, including values and ranges thereof, such as 1-1000 nm, 10-1000 nm, 30-1000 nm, 30-900 nm, 30-800 nm, 30-750 nm, 100-1000 nm, 100-900 nm, and the like.. The term also covers sustained release structures comprising nutrients / ingredients encapsulated by films or held in nanopores within a carrier material such as clays. The term also refers to the term “nanofertilizer” defined as materials in the nanometer scale, usually in the form of nanoparticles, containing macro and micronutrient, plant nutrient particles that are delivered to crops in a controlled mode. In the scope of this invention, “nanofertilizer” refers to nanoparticle which can be applied to a plant to benefit or support the plant growth, plant health, yield, vigor, disease resistance, productivity, and nutrient assimilation. The term also refers to a composition having one or more nanoparticle ingredients or a composition wherein the particle size of the resulting composites formed by mixing various ingredients, nutrients of the composition is in nanometric scale ranging between 0.1 nm to 5000 nm, preferably in the range of 1-1000 nm. The term encompasses following three types: 1) nanoscale fertilizer, which corresponds to the conventional fertilizer reduced in size typically in the form of nanoparticles; 2) nanoscale additive fertilizer, which is a traditional fertilizer containing a supplement nanomaterial; and 3) nanoscale coating fertilizer, refers to nutrients encapsulated by nanofilms or intercalated into nanoscale pores of a host material.

[0040] The term “weak acid” as used herein refers to any material having a pH range of 3 to 6. It also refers to acids which do not completely dissociate in the solution.

[0041] The term “Banana” or “banana” as used herein refers to an elongated, edible fruit - botanically a berry - produced by several kinds of large herbaceous flowering plants in the genus Musa and family Musaceae. The term is used synonymously with the term “plantain”. The term covers wild types, cultivars, variants, hybrids, and genetically modified versions of species belonging to the genus Musa. The term banana extract refers to an extract of the entire banana plant or a part thereof. The extract may be derived from the whole plant including roots, bulbs, rhizomes, leaves, stems, buds, flowers, flower reproductive organs, seeds, fruits, peel / skin, and so forth. The term may refer to an extract of a particular plant part or parts listed herein.

[0042] The term “Lotus” or “lotus” as used herein refers to an extant species of aquatic plant in the family Nelumbonaceae. The term is synonymous with the names Nelumbo spp, Nelumbo nucifera, sacred lotus, Laxmi lotus, Indian lotus, water lily, or simply lotus. The term covers wild types, variants, hybrids, and genetically modified versions of species belonging to the genus Nelumbo. The term “lotus extract” refers to an extract of the entire lotus plant or a part thereof. The extract may be derived from the whole plant including roots, bulbs, rhizomes, leaves, stems, buds, flowers, flower reproductive organs, seeds, fruits, and so forth. The term may refer to an extract of a particular plant part or parts listed herein. The term “lotus leaf extract” refers to an extract of one or more leaves of lotus. It may also include an extract of the stem with which the leaf is attached.

[0043] The term “seed” as used herein embraces seeds and plant propagules of all kinds including but not limited to true seeds, seed pieces, suckers, corms, bulbs, fruit, tubers, grains, cuttings, cut shoots and the like.

[0044] The term “seed treatment” as used herein comprises all suitable seed treatment techniques known in the art, such as seed dressing, seed coating, seed dusting, seed soaking and seed pelleting.

[0045] The term “locus” as used herein shall denote the vicinity of the target plant or a part thereof in which growth stimulation is desired. The locus includes the vicinity of the target plant or a part thereof which has either emerged or is yet to emerge. The term “target plant” shall include a multitude of desired crop plants or an individual crop plant growing at a locus. The said locus includes the area, medium and soil where the target plant or a part thereof grows. For simplicity of reference, the target plant is referred synonymously as “plant” in the context of the present invention.

[0046] The term “raw material form” as used herein refers to untreated and / or commercially procured form of a nutrient / plant nutrient comprising nitrogen, phosphorus, potassium, or a combination thereof.

[0047] The term “amino acid source” as used herein refers to any composition(s) which has concentrated amounts of amino acids or wherein amino acids form a major component of its constitution. Said composition(s) may be naturally derived, such as extracts obtained from animal source, vegetable / plant source or microbial source (bacteria, yeasts, fungi, etc.) Said composition(s) may be synthetically produced. Said composition(s) may comprise one or more or all of the 20 known amino acids, including L-forms, D-forms or racemic mixtures.

[0048] The term “growth stimulation” as used herein refers to any improvement in plant health, phenotypic or genotypic characteristics of a plant; visible beneficial changes in a plant; improvement in plant stress and disease tolerance and resistance and improvement in yield and quality of produce. The term also refers to initiation or acceleration of growth of the plant or a part thereof. Non-limiting examples of changes or improvement effected by the combinations and compositions of the present invention include: Improved plant nutrient use efficiency; Enhanced root and shoot growth; Improved reproductive heat stress tolerance; Improved drought tolerance; Improved pollen tube growth; Enhanced pollen viability; Increased fertilization and fruit set; Increased floral inflorescence primordia; Increased number of buds, pods and yield; Improved and strong root mass and architecture; Improved / increased bud development; Accelerated shoot or bud emergence; Enhanced vigor / uniformity of emergence; Improved and increased branching; Improved / increased diameter and strength; Improved / increased inter-node length; Increase in number of yield structures (ears, fruits etc); Increase in leaf area; Increased amount of chlorophyll, greening; Increased photosynthesis activity; Increase in CO2 fixation; Accelerated and improved flowering; Improvement in pollination; Enhanced fruit set & retention; Improvement in cell division for size and quality potential; Improvement in fruit finish; Freedom from pest such as fungal pests, viruses, bacteria, weeds, insects, nematodes; Enhanced resistance against pest such as fungal pests, viruses, bacteria, weeds, insects, nematodes; Increased plant weight; Increased plant height; Increased biomass such as higher overall fresh weight; Higher grain yield; More tillers; Larger leaves; Increased shoot growth; Increased protein content; Increased oil content; Increased starch content; Increased pigment content; Increased plant vigor; Improved vitality of the plant; Improved plant growth; Improved plant development; Improved visual appearance of the plant or a part thereof; Improved plant stand (less plant verse / lodging); Improved emergence; Enhanced nodulation, in particular rhizobial nodulation; Bigger leaf blade; Increased yield when grown on poor soils or unfavorable climate; Enhanced pigment content (e.g. Chlorophyll content); Earlier flowering; Earlier fruiting; Earlier and improved germination; Earlier grain maturity; Improved self-defence mechanisms; Improved stress tolerance and resistance of the plants against biotic and abiotic stress factors such as fungi, bacteria, viruses, insects, heat stress, cold stress, drought stress, UV stress and / or salt stress; Less non-productive tillers; Less dead basal leaves; Less input needed (such as fertilizers or water); Greener leaves; Complete maturation under shortened vegetation periods; Less fertilizers needed; Less seeds needed; Easier harvesting; Faster and more uniform ripening; Longer shelf-life; Longer panicles; Delay of senescence; Stronger and / or more productive tillers; Better extractability of ingredients; Improved quality of seeds (for being seeded in the following seasons for seed production); Reduced production of ethylene and / or the inhibition of its reception by the plant; Increased nutrient content; Increased content of fatty acids; Increased metabolite content; Increased carotenoid content; Increased sugar content; Increased amount of essential amino acids Improved nutrient composition; Improved protein composition; Improved composition of fatty acids; Improved metabolite composition; Improved carotenoid composition; Improved sugar composition; Improved amino acids composition; Improved or optimal fruit color; Improved leaf color; Higher storage capacity; and / or Higher processability of the harvested products.

[0049] The term “energy expenditure” as used herein refers to involvement of heating or cooling steps incorporated in the process. Said steps involve influx of external energy which contribute to energy expenditure and incurs time and cost.

[0050] An embodiment of the present invention provides a process of preparing an agricultural fertilizer composition, said process comprising:

[0051] A. providing a homogenous solution of a plant extract;

[0052] B. solubilizing in the homogenous solution of the plant extract a weak acid;

[0053] C. adding a stabilizer to the solution of step B and solubilizing to obtain a homogenous solution;

[0054] D. adding and solubilizing an amino acid or an amino acid source to homogenous solution obtained in step C; and

[0055] E. mixing the raw material form of a nutrient particle, or a plurality of raw material forms of nutrient particles in the homogenous solution obtained in step D to obtain a final composition, wherein the nutrient particle or the plurality of nutrient particles is / are a plant nutrient selected from nitrogen, its compounds or salts; phosphorus, its compounds or salts; potassium, its compounds or salts; or combinations thereof.

[0056] In an embodiment, the final composition obtained has a zeta potential in the range of about +20 mV to about -20 mV. In an embodiment, the final composition obtained has a zeta potential in the range of about +17 mV to about -17 mV. In an embodiment, the final composition obtained has a zeta potential in the range of about +15 mV to about -15 mV. In an embodiment, the final composition obtained has a zeta potential in the range of about +14 mV to about -14 mV.

[0057] In an embodiment, the particle size of resultant particles or nutrient particles or plurality of nutrient particles present in the final composition ranges from about 1 nm to about 5,000 nm. In an embodiment, the particle size of resultant particles or nutrient particles present in the final composition ranges from about 1 nm to about 4,000 nm. In an embodiment, the particle size of resultant particles or nutrient particles present in the final composition ranges from about 1 nm to about 3,000 nm. In an embodiment, the particle size of resultant particles or nutrient particles present in the final composition ranges from about 1 nm to about 2,000 nm. In an embodiment, the particle size of resultant particles or nutrient particles present in the final composition ranges from about 1 nm to about 1,000 nm. In a preferred embodiment, the particle size of resultant particles or nutrient particles present in the final composition ranges from about 1 nm to about 800 nm. In a preferred embodiment, the particle size of resultant particles or nutrient particles present in the final composition ranges from about 10 nm to about 700 nm. In a preferred embodiment, the particle size of resultant particles or nutrient particles present in the final composition ranges from about 10 nm to about 600 nm. In a preferred embodiment, the particle size of resultant particles or nutrient particles present in the final composition ranges from about 20 nm to about 550 nm.

[0058] In an embodiment, the nutrient particles or resultant particles of the final composition are nanoparticles. In an embodiment, the nutrient particles or the resultant particles of the final composition have a particle size in the range of 1 nm to 5000 nm. The resultant particles of the final composition are the particles present in the final composition. Such resultant particles may comprise aggregates of any or all components. Thus, the resultant particles of the final composition may comprise individually of nutrient particle, plant extract substances, stabilizer, weak acid, amino acid source, optional humic substance, optional stabilizing agent, optional agriculturally acceptable excipient(s) or any combinations thereof. Thus, it can be said that the final composition obtained in the process of the present invention comprise nutrient particles which may be in form of nanoparticles. Thus, it can also be said that the final composition obtained in the process of the present invention comprise a plurality of nutrient particles which may be in form of nanoparticles.

[0059] In an embodiment, the process of the present invention is characterized by absence of energy expenditure, particularly, involvement of heat. The process is characterized by absence of heating and cooling steps for homogenous solubilization of the raw material form of nutrient particle or a plurality of nutrient particles.

[0060] In an embodiment, the homogenous solution of a plant extract in step A has a pH of about 6-7.

[0061] In an embodiment, step B is followed by agitation conducted at around 500 rpm to about 5000 rpm. Preferably, the agitation after step B is conducted at 1000 rpm. In an embodiment, addition of weak acid involves addition of at least one weak acid to the homogenous plant extract. In an embodiment, addition of weak acid involves addition of at least two weak acids during the complete process. In an embodiment, the two weak acids may be added together or separately. In an embodiment, one of the two weak acids is added to the homogenous plant extract of step A, and the other weak acid is added as a pH stabilizer to the final composition obtained in step E.

[0062] In an embodiment, addition of a weak acid to the homogenous solution of a plant extract reduces the pH of the mixture to about 2-3. Said pH facilitates stable solubilization and homogenization of the stabilizer and the raw material form of nutrient particle, or a plurality of nutrient particles, thus not requiring any energy expenditure and separate pH stabilizer for solubilization and homogenization of these components. This step facilitates direct step-wise addition of components and their stable homogenous solubilization in the solution. This step eradicates any need for separate stabilizer preparation with suitable pH, thus saving time and resources. Thus, the direct step-wise addition of components to obtain a final composition can be termed as a linear process which simplifies the process of making the desired composition.

[0063] In an embodiment, step C is followed by agitation conducted at around 500 rpm to about 5000 rpm. Preferably, the agitation after step C is conducted at 1000 rpm. The stabilizer readily dissolves in the resulting mixture of step B due to the pH in the range of 2-3.

[0064] In another embodiment, the step D involves adding and solubilizing an amino acid or an amino acid source along with an optional humic substance to homogenous solution obtained in step C.

[0065] In an embodiment, the raw material form of nutrient particle or the raw material forms of plurality of nutrient particles is / are milled prior to adding to the homogenous solution obtained in step D. The type of milling employed is selected by a skilled person equipped with knowledge of any suitable and conventional types of milling for said raw material form(s).

[0066] In an embodiment, an optional additional stabilizing agent is further added to the final composition. In an embodiment, said additional stabilizing agent(s) comprise a pH stabilizer. In an embodiment, the pH stabilizer is the only additional stabilizing agent or additional stabilizing agent(s) comprise one or more agent(s) in addition to the pH stabilizer.

[0067] In an embodiment, a pH stabilizer is added to the final composition as an additional stabilizing agent. In an embodiment, the pH stabilizer may be selected from alkaline or acidic pH stabilizers. The pH stabilizer may be selected from acids or alkali solutions. In an embodiment, the alkali solution is sodium hydroxide and / or potassium hydroxide. In an embodiment, acidic pH stabilizer may be a weak acid selected from the weak acids embodied in the specification. In a preferred embodiment, malic acid may be used as a pH stabilizer.

[0068] In an embodiment, an optional an agriculturally acceptable excipient is added to the final composition.

[0069] In an embodiment, said process of preparing the agricultural fertilizer composition does not require energy expenditure for homogenous and stable solubilization of components, particularly the raw material form of the nutrient particle. Energy expenditure refers to any heating or cooling processes in the process or method of preparing the composition. In a preferred embodiment, said process is operated at room temperature. In another embodiment, said process is an energy efficient process conducted without energy expenditure for homogenous and stable solubilization of components, particularly the raw material form of the nutrient particle.

[0070] The process embodied in the present invention offers an advantage in terms of homogeneity of the solution by avoiding sedimentation, flocculation, aggregation, coagulation of components of the composition during the process due to absence of heating or cooling steps. Sedimentation, flocculation, aggregation, coagulation of components of the composition is a common issue observed when heating or cooling processes are involved in a process.

[0071] Another advantage offered by the process embodied in the present invention is time and energy conservation as components can be added in a linear sequence without requiring the need for preparation of separate solutions which are further added while making the composition. For example, the stabilizer need not be separately dissolved in a solution of suitable pH to form a stabilizer solution which is further added to the main process of preparing the agricultural composition. This also prevents wastage of component materials used to make the composition.

[0072] In an embodiment, the method of preparing an agricultural composition comprises adding an additional stabilizing agent to the final composition obtained in step E. Alternatively, said additional stabilizing agent is added after addition of optional pH stabilize^ s) and / or optional agriculturally acceptable excipient(s).

[0073] In an embodiment, the final composition obtained in step E is stirred for about 2 to 8 hours to filtration at around 500 rpm to about 5000 rpm. In another embodiment, the final composition obtained after the addition of the optional pH stabilizer(s), optional agriculturally acceptable excipient(s), and / or optional additional stabilizing agent(s) to the composition obtained in step E, is stirred for about 2 to 8 hours to filtration at around 500 rpm to about 5000 rpm.

[0074] In an embodiment, the resulting compositions prepared by the methods described herein are stable, homogenous compositions. In a preferred embodiment, the resulting compositions prepared by the methods described herein are stable nanoparticle compositions. The resulting / final compositions prepared by the methods described herein are stable nanofertilizer compositions.

[0075] The inventors also observed that said process, surprisingly resulted in a composition which did not show any gas formation and crystallization during the storage. This is advantageous as earlier known compositions comprising nutrient particles such as urea or DAP are known to generate gas during storage and thereby making transport difficult and dangerous. Also, the earlier known compositions have been observed to have crystallized during storage. The composition obtained by the process of present invention overcomes these challenges.

[0076] Thus, in an embodiment, the compositions obtained by the process of the present invention are characterized by absence of gas generation and crystallization. Said gas is ammonia gas and may comprise other gases in traces.

[0077] The term “absence of gas generation” refers to a characteristic of a product which is devoid of gas generation over a period of time, particularly during storage conditions ranging from temperatures as low as -10 degree C to higher temperatures such as 50-degree C. In context of the present specification, gas generation is quantified in terms of rate of pressure generation (Kg / Cm2). The term as used herein refers to rate of pressure generation of 0.02 Kg / Cm2or less at a temperature ranging from about 35 degree C to about 50 degree C.

[0078] In an embodiment, the nutrient particle, wherein the nutrient particle is a plant nutrient, is nitrogen, its compounds or salts. In another embodiment, the nutrient particle is a nitrogenous compound.

[0079] In an embodiment, the nutrient particle, wherein the nutrient particle is a plant nutrient, is phosphorus, its compounds or salts. In another embodiment, the nutrient particle is a phosphorous-containing compound. In an embodiment, the nutrient particle, wherein the nutrient particle is a plant nutrient, is potassium, its compounds or salts. In another embodiment, the nutrient particle is a potassium- containing compound.

[0080] In a preferred embodiment, the process comprises adding a plurality of nutrient particles, wherein the plurality of nutrient particles is a combination of one or more types of nutrient particles.

[0081] In an embodiment, the combinations of nutrient particles added in the process of the present invention may be selected from: i) a plurality of nutrient particles comprising a nutrient particle comprising nitrogen, its compounds or salts; and phosphorus, its compounds or salts; ii) a plurality of nutrient particles comprising a nutrient particle comprising potassium, its compounds or salts; and phosphorus, its compounds or salts; iii) a plurality of nutrient particles comprising a nutrient particle comprising nitrogen, its compounds or salts; and potassium, its compounds or salts; iv) a plurality of nutrient particles comprising a nutrient particle comprising nitrogen, its compounds or salts; phosphorus, its compounds or salts; and potassium, its compounds or salts.

[0082] In a preferred embodiment, the combinations of nutrient particles added in the process of the composition of the present invention is a plurality of nutrient particles comprising a nutrient particle comprising nitrogen, its compounds or salts; and phosphorus, its compounds or salts.

[0083] In a preferred embodiment, the combinations of nutrient particles added in the process of the composition of the present invention is a plurality of nutrient particles comprising a nutrient particle comprising nitrogen, its compounds or salts; phosphorus, its compounds or salts; and potassium, its compounds or salts.

[0084] In an embodiment, the nutrient particle comprises nitrogen, its compounds or salts. In an embodiment, the nitrogen-containing nutrient particle is a nitrogen-containing plant nutrient or a nitrogen-containing fertilizer such as those selected from the group consisting of urea (carbamide), ammonium compounds, ammonium fertilizer, urea ammonium nitrate (UAN), cyanamide, guanidine nitrate, dicyandiamide (DCD), guanyl urea sulphate, thiourea, urea formaldehyde polymer, amino acids, amines, amino alcohols, amides, lactams, nitro compounds, imines, nitriles, diazonium salts, hydrazides, carbazides, oximes, alkyl nitrates, nitrosamines, nitroarenes, peroxyacyl nitrates and heterocyclic compounds such as imidazole, triazole, and tetrazole and salts or derivatives thereof.

[0085] In a preferred embodiment, the nutrient particle comprising nitrogen / nitrogen-containing plant nutrient / nitrogen-containing fertilizer is urea or salts or derivatives thereof. Examples of derivatives of urea include, but not limited to, N-(2-hydroxyethyl)urea; N-(2- hydroxypropyl)urea; N-(3-hydroxypropyl)urea; N-(2,3-dihydroxypropyl)urea; N-(2,3,4,5,6- pentahydroxyhexyl)urea; N-methyl-N-(l,3,4,5,6-pentahydroxy-2-hexyl)urea; N-methyl-N'- (l-hydroxy-2-methyl-2-propyl)urea; N-(l-hydroxy-2-methyl-2-propyl)urea; N-(l,3- dihydroxy-2-propyl)urea; N-(trishydroxymethylmethyl)urea; N-ethyl-N'-(2- hydroxyethyl)urea; N,N-bis(2-hydroxyethyl)urea; N,N'-bis(2-hydroxyethyl)urea; N,N-bis(2- hydroxypropyl)-urea; N,N'-bis(2-hydroxypropyl)urea; N,N-bis(2-hydroxyethyl)-N'- propylurea; N,N-bis(2-hydroxypropyl)-N'-(2-hydroxyethyl) urea; N-tert-butyl-N'-(2- hydroxyethyl)-N'-(2-hydroxypropyl)urea; N-(l,3-dihydroxy-2-propyl)-N'-(2- hydroxyethyl)urea; N,N-bis(2-hydroxyethyl)-N',N'-dimethylurea; N,N,N',N'-tetrakis(2- hydroxyethyl)urea; N',N'-bis(2-hydroxyethyl)-N',N'-bis(2-hydroxypropyl)urea, and mixtures thereof.

[0086] In a preferred embodiment, the nutrient particle comprising nitrogen / nitrogen-containing plant nutrient / nitrogen-containing fertilizer is an ammonium fertilizer selected from ammonium sulphate, ammonium nitrate, urea ammonium nitrate, anhydrous ammonia, aqueous ammonia, and combinations thereof.

[0087] In an embodiment, the nutrient particle comprises nitrogen, its compounds or salts, and phosphorus, its compounds or salts, and is also referred to herein as nitrogen and phosphorous- containing plant nutrient or a nitrogen and phosphorous-containing fertilizer. In a preferred embodiment, the nutrient particle comprising a combination of nitrogen, its compounds or salts, and phosphorus, its compounds or salts is an inorganic ammonium salt selected from ammonium phosphate, diammonium phosphate (DAP), monoammonium phosphate (MAP), and combinations thereof.

[0088] In yet another embodiment, the nutrient particle comprising nitrogen, phosphorus, potassium, or a combination thereof is a nitrogen and / or phosphorus and / or potassium containing waste fertilizer, for example, manure or animal excreta, protein mixtures, green manure, fish products, crop residues and other natural materials known to be sources of N or ammonium ions, P or phosphate ions, K or potassium ions, and or various combinations of the foregoing.

[0089] In an embodiment, the nutrient particle comprises potassium, its compounds or salts. In an embodiment, the potassium-containing nutrient particle is a potassium-containing plant nutrient or a potassium-containing fertilizer. In an embodiment, the nutrient particle comprising potassium / potassium-containing plant nutrient / potassium-containing fertilizer is potassium chloride, potash or muriate of potash.

[0090] In an embodiment, the plant extract belongs to an angiosperm plant or a part thereof. Preferably, in an embodiment, the plant extract is an extract of a plant or a part of plant, wherein the plant is selected from Nelumbonaceae, Musaceae, Rutaceae, Brassicaceae, Moringaceae, Poaceae, Piperaceae, Asphodelaceae, Fabaceae, Phyllanthaceae, Solanaceae, Anacardiaceae, Myrtaceae, Elaeocarpaceae, and combinations thereof. More preferably, in an embodiment, the plant extract is an extract of a plant, or a part of plant selected from the group consisting of genera Nelumbo, Musa, Moringa, Citrus, Brassica, Avena, Cymbopogon, Piper, Tamarindus, Aloe, Phyllanthus, Capsicum, Zea, Mangifera, Solanum, Eucalyptus, Syzygium, Psidium, Elaeocarpus, and combinations thereof. Even more preferably, in an embodiment, the plant extract is an extract of plant, or a part of a plant selected from the group consisting of lotus, banana, moringa, lemon, lime, mustard, oats, betel vine, tamarind, aloe vera, Indian gooseberry (amla), maize, mango, chili, tomato, guava, jamun, plum, rudraksh, eucalyptus, grasses such as lemon grass, and combinations thereof.

[0091] In a preferred embodiment, the plant extract is an extract of lotus, or a part thereof. Preferably, the plant extract is a lotus leaf extract.

[0092] In a preferred embodiment, the plant extract is an extract of banana, or a part thereof. Preferably, the plant extract is a banana leaf extract.

[0093] In a preferred embodiment, the plant extract is an extract of betel vine, or a part thereof. Preferably, the plant extract is a betel vine leaf extract.

[0094] In a preferred embodiment, the plant extract is an extract of moringa, or a part thereof. Preferably, the plant extract is a moringa leaf extract.

[0095] In a preferred embodiment, the plant extract is an extract of eucalyptus, or a part thereof. Preferably, the plant extract is a eucalyptus leaf extract. In a preferred embodiment, the plant extract is an extract of mango, or a part thereof. Preferably, the plant extract is a mango leaf extract.

[0096] In a preferred embodiment, the plant extract is an extract of chili, or a part thereof. Preferably, the plant extract is a chili leaf extract.

[0097] In a preferred embodiment, the plant extract is an extract of tomato, or a part thereof. Preferably, the plant extract is a tomato leaf extract.

[0098] In a preferred embodiment, the plant extract is an extract of maize, or a part thereof. Preferably, the plant extract is a maize leaf extract.

[0099] In a preferred embodiment, the plant extract is an extract of gooseberry (amla), or a part thereof. Preferably, the plant extract is a gooseberry fruit extract.

[0100] In a preferred embodiment, the plant extract is an extract of guava, or a part thereof. Preferably, the plant extract is a guava leaf extract.

[0101] In a preferred embodiment, the plant extract is an extract of jamun, or a part thereof. Preferably, the plant extract is a jamun leaf extract.

[0102] In a preferred embodiment, the plant extract is an extract of rudraksh, or a part thereof. Preferably, the plant extract is a rudraksh leaf extract.

[0103] In a preferred embodiment, the plant extract is a combination of banana extract or banana leaf extract and plant extract or leaf extracts of lotus, moringa, lemon, lime, mustard, oats, betel vine, tamarind, aloe vera, Indian gooseberry (amla), maize, mango, chili, tomato, guava, jamun, plum, rudraksh, eucalyptus, grasses such as lemon grass.

[0104] In a preferred embodiment, the plant extract is an extract of lotus and banana, or parts thereof. Preferably, the plant extract is a combination of lotus leaf extract and banana leaf extract.

[0105] In a preferred embodiment, the plant extract is an extract of betel vine, moringa and banana, or parts thereof. Preferably, the plant extract is a combination of betel vine leaf extract, moringa leaf extract and banana leaf extract.

[0106] In one embodiment, the present invention provides a process for the preparation of plant extracts, in particular lotus leaf extract, banana leaf extract, betel vine leaf extract and Moringa extract. In an embodiment, the stabilizer may act as pH balancing agent, a chelating agent, a solubilizing agent, an encapsulating agent, or an anti-flocculant.

[0107] In an embodiment, the stabilizer is a polycation polymer selected from polyamidoamine, polyethylenimine, mannosylated polyethylenimine, chitosan, chitosan derivatives, poly(allylamine), poly(l-lysine), poly(dimethyldiallylammonium chloride), and poly(allylamine hydrochloride); or combinations thereof. Preferably, the stabilizer is chitosan.

[0108] In an embodiment, a weak acid has a pH range of 3 to 6. In an embodiment, the weak acid is selected from the group consisting of citric acid, malic acid, lactic acid, formic acid, acetic acid, benzoic acid, carbonic acid, and salts or derivatives thereof. In an embodiment, the weak acid is a combination of one or more weak acids or salts or derivatives thereof.

[0109] In an embodiment, the composition of the present invention comprises at least one weak acid. In an embodiment, the composition of the present invention comprises at least two weak acids.

[0110] In a preferred embodiment, the weak acid is citric acid.

[0111] In a preferred embodiment, the weak acid is malic acid.

[0112] In a preferred embodiment, the weak acid is malic acid, citric acid, or combinations thereof.

[0113] In another embodiment, the composition comprises malic acid as a pH stabilizer.

[0114] In an embodiment, the amino acid source is an extract comprising an amino acid.

[0115] The term “amino acid” comprise one or more of 20 known amino acids. It comprises D-amino acids, L-amino acids, or combinations thereof.

[0116] In an embodiment, the extracts comprising an amino acid are selected from microbial extracts, vegetable extracts, or combinations thereof.

[0117] In an embodiment, the amino acid may be an L-amino acid, or derivatives thereof. In an embodiment, the amino acid or L-amino acid is selected from the group consisting of lysine, glycine, aspartic acid, alanine, tryptophan, proline, isoleucine, histidine, leucine, threonine, glutamic acid, tyrosine, serine, glutamine, phenylalanine, cysteine, valine, asparagine, arginine, sarcosine, L-lysine, L-glycine, L-aspartic acid, L-alanine, L-tryptophan, L-proline, L- isoleucine, L-histidine, L-leucine, L-threonine, L-glutamic acid, L-tyrosine, L-serine, L- glutamine, L-phenylalanine, L-cysteine, L-valine, L-asparagine, L-arginine, L-sarcosine, and combinations thereof. In a preferred embodiment, the amino acid or L-amino acid is methionine or L-methionine. In another preferred embodiment, the amino acid or L-amino acid is a combination of one or more amino acids or L-amino acids selected from lysine, glycine, aspartic acid, alanine, tryptophan, proline, isoleucine, histidine, leucine, threonine, glutamic acid, tyrosine, serine, glutamine, phenylalanine, cysteine, valine, asparagine, arginine, sarcosine, L-lysine, L-glycine, L-aspartic acid, L-alanine, L-tryptophan, L-proline, L- isoleucine, L-histidine, L-leucine, L-threonine, L-glutamic acid, L-tyrosine, L-serine, L- glutamine, L-phenylalanine, L-cysteine, L-valine, L-asparagine, L-arginine, L-sarcosine. In an embodiment, the amino acid or L-amino acid is derived from a synthetic source or a natural source. In an embodiment, the amino acid or L-amino acid is derived from microorganisms such as bacteria, fungi, or acid hydrolysis of a cereal such as soy, cereals, quinoa, or the likes.

[0118] In an embodiment, wherein an amino acid source is an extract comprising amino acid, said extract is a microbial extract. In an embodiment, the microbial extract is an extract of a microorganism selected from bacteria, fungi or combinations thereof. The microbial extract may be a cell-free extract, such as a supernatant of cell lysate or fermentation media without microorganisms. The microbial extract may be live cells or fermentation media comprising microorganisms. In an embodiment, the microbial extract comprises a Bacillus species or an extract of a Bacillus species. In an embodiment, the microbial extract comprises a Pseudomonas species or an extract of a Pseudomonas species. In a preferred embodiment, the microbial extract is a yeast extract. Yeast extract may or may not comprise live cells or cell debris. Yeast extract comprises amino acids, particularly sulfur-containing amino acids such as methionine and cysteine. In an embodiment, the yeast is selected from the genera Saccharomyces, Kluyveromyces, Hanseniaspora, Metschnikowia, Pichia, Starmerella, Torulaspora, Brettanomyces, Lachancea, Schizosaccharomyces or Candida.

[0119] In an embodiment, the extract comprising an amino acid (amino acid source) is a vegetable extract. The vegetable extract may be an extract of leguminous plants, cereals, soy, quinoa, or the likes.

[0120] In one embodiment, the present invention provides a process for the preparation of microbial extracts, in particular yeast extract.

[0121] In one embodiment, the present invention provides a process for the preparation of amino acid extract, preferably the amino acid extract obtained from a vegetable source. In an embodiment, the humic substance is selected from humic acid, fulvic acid, or a combination thereof. Preferably, the humic substance is fulvic acid. Preferably, the humic substance is humic acid. Preferably, the humic substance is fulvic acid and humic acid.

[0122] In an embodiment, the additional stabilizing agent is a pH stabilizing agent / pH stabilizer. In an embodiment, the pH stabilizer may be selected from alkaline or acidic pH stabilizers. The pH stabilizer may be selected from acids or alkali solutions. In an embodiment, the alkali solution is sodium hydroxide and / or potassium hydroxide. In an embodiment, acidic pH stabilizer may be a weak acid selected from the weak acids embodied in the specification. In a preferred embodiment, malic acid may be used as a pH stabilizer.

[0123] In an embodiment, the additional stabilizing agent is a sugar. The sugar is any or a combination of monosaccharides, disaccharides, oligosaccharides, polysaccharides, polymers, derivatives thereof. In an embodiment, the sugar is selected from cellulose, and carboxymethyl cellulose or its salts such as sodium salt, chitooligosaccharides, dextran, starch, alginate, karragenans, hyaluronic acid, derivatives, and combinations thereof.

[0124] The agrochemically suitable excipient may be any one or a combination of adjuvants, cosolvents, surfactants, colorants, dispersants, emulsifiers, thickeners, antifreeze agents, antifoam agents, wetting agents, solvents, preservatives, or a mixture thereof which may be optionally added to the compositions of the present invention.

[0125] In an embodiment, the surfactants may be selected from non-ionic, anionic or cationic surfactants.

[0126] Examples of nonionic surfactants include polyarylphenol polyethoxy ethers, polyalkylphenol polyethoxy ethers, polyglycol ether derivatives of saturated fatty acids, polyglycol ether derivatives of unsaturated fatty acids, polyglycol ether derivatives of aliphatic alcohols, polyglycol ether derivatives of cycloaliphatic alcohols, fatty acid esters of polyoxyethylene sorbitan, alkoxylated vegetable oils, alkoxylated acetylenic diols, polyalkoxylated alkylphenols, fatty acid alkoxylates, sorbitan alkoxylates, polyoxyethylene sorbitol, sorbitol esters, polysorbate, C8-C22 alkyl or alkenyl polyglycosides, polyalkoxy styrylaryl ethers, alkylamine oxides, block copolymer ethers, polyalkoxylated fatty glyceride, polyalkylene glycol ethers, linear aliphatic or aromatic polyesters, organo silicones, polyaryl phenols, sorbitol ester alkoxylates, polyalkylene oxide block copolymers, acrylic copolymers and mono- and diesters of ethylene glycol and mixtures thereof. Examples of anionic surfactants include alcohol sulfates, alcohol ether sulfates, alkylaryl ether sulfates, alkylaryl sulfonates such as alkylbenzene sulfonates and alkylnaphthalene sulfonates and salts thereof, alkyl sulfonates, mono- or di-phosphate esters of polyalkoxylated alkyl alcohols or alkylphenols , mono- or di-sulfosuccinate esters of C12-C15 alkanols or polyalkoxylated C12-C15 alkanols, alcohol ether carboxylates, phenolic ether carboxylates, polybasic acid esters of ethoxylated polyoxyalkylene glycols consisting of oxybutylene or the residue of tetrahydrofuran, sulfoalkylamides and salts thereof such as N-methyl-N- oleoyltaurate Na salt, polyoxyalkylene alkylphenol carboxylates, polyoxyalkylene alcohol carboxylates alkyl polyglycoside / alkenyl succinic anhydride condensation products, alkyl ester sulfates, napthalene sulfonates, naphthalene formaldehyde condensates, alkyl sulfonamides, sulfonated aliphatic polyesters, sulfate esters of styrylphenyl alkoxylates, and sulfonate esters of styrylphenyl alkoxylates and their corresponding sodium, potassium, calcium, magnesium, zinc, ammonium, alkyl ammonium, diethanolammonium, or tri ethanolammonium salts, salts of ligninsulfonic acid such as the sodium, potassium, magnesium, calcium or ammonium salt, polyarylphenol polyalkoxyether sulfates and polyarylphenol polyalkoxyether phosphates, and sulfated alkyl phenol ethoxylates and phosphated alkyl phenol ethoxylates.

[0127] Cationic surfactants include alkanol amides of Cs-Cis fatty acids and Cs-Cis fatty amine polyalkoxylates, Cio-Cis alkyldimethylbenzylammonium chlorides, coconut alkyldimethylaminoacetic acids, and phosphate esters of Cs-Cis fatty amine polyalkoxylates.

[0128] In another embodiment, antifreeze agent(s) added to the composition may be alcohols selected from the group comprising of but not limited to ethylene glycol, 1,2-propylene glycol, 1,3- propylene glycol, 1,2-butanediol, 1,3 -butanediol, 1,4-butanediol, 1,4-pentanediol, 3-methyl- 1,5-pentanediol, 2,3 -dimethyl-2, 3 -butanediol, trimethylol propane, mannitol, sorbitol, glycerol, pentaerythritol, 1,4-cyclohexanedimethanol, xylenol, bisphenols such as bisphenol A or the like. In addition, ether alcohols such as diethylene glycol, triethylene glycol, tetraethylene glycol, polyoxyethylene or polyoxypropylene glycols of molecular weight up to about 4000, diethylene glycol monomethylether, diethylene glycol monoethylether, triethylene glycol monomethylether, butoxyethanol, butylene glycol monobutylether, dipentaerythritol, tripentaerythritol, tetrapentaerythritol, diglycerol, triglycerol, tetraglycerol, pentaglycerol, hexaglycerol, heptaglycerol, octaglycerol.

[0129] In an embodiment, the preservative is selected from l,2-benzisothiazolin-3-one; dipropylene glycol solution of l,2-benzisothiazolin-3-one; 2-Methyl-2H-isothiazol-3-one; sodium benzoate; potassium benzoate; benzoic acid; sorbic acid; potassium sorbate; sodium sulphite; potassium sulphite; sodium bisulphite; potassium bisulphite; sodium metabisulphite; potassium metabisulphite; sodium methylparaben; citric acid or salts thereof; malic acid or salts thereof; tartaric acid or salts thereof; and propionic acid or salts thereof.

[0130] An embodiment of the present invention provides an agricultural fertilizer composition obtainable by the process of the present invention. An embodiment of the present invention provides an agricultural nanofertilizer composition obtainable by the process of the present invention.

[0131] Thus, an embodiment of the present invention provides an agricultural fertilizer composition comprising: a) a plant extract; b) a weak acid; c) a stabilizer; d) an amino acid or an amino acid source; and e) a nutrient particle or a plurality of nutrient particles, wherein the nutrient particle is a plant nutrient selected from nitrogen, its compounds or salts; phosphorus, its compounds or salts; potassium, its compounds or salts; or combinations thereof.

[0132] In an embodiment, said composition further comprises a humic substance selected from humic acid, fulvic acid, or combinations thereof.

[0133] In an embodiment, said composition further comprises an additional stabilizing agent(s).

[0134] In an embodiment, said composition further comprises an agriculturally acceptable excipient.

[0135] An embodiment of the present invention provides an agricultural composition comprising: a) a plant extract; b) a weak acid; c) a stabilizer; d) an amino acid or an amino acid source; e) a nutrient particle or a plurality of nutrient particles, wherein the nutrient particle is a plant nutrient selected from nitrogen, its compounds or salts; phosphorus, its compounds or salts; potassium, its compounds or salts; or combinations thereof; f) a humic substance selected from humic acid, fulvic acid, or combinations thereof; g) optionally, an additional stabilizing agent; and h) optionally, an agriculturally acceptable excipient.

[0136] In an embodiment, the size of said nutrient particle or plurality of nutrient particles in the composition ranges from about 1 nm to about 5000 nm, more specifically about 1 nm to about 1000 nm.

[0137] Yet another embodiment of the present invention provides an agricultural composition comprising: a) a plant extract; b) a weak acid; c) a stabilizer; d) an animo acid or an amino acid source; e) a nutrient nanoparticle or a plurality of nutrient nanoparticles, wherein the nutrient nanoparticle is a plant nutrient selected from nitrogen, its compounds or salts; phosphorus, its compounds or salts; potassium, its compounds or salts; or combinations thereof; f) optionally, a humic substance selected from humic acid, fulvic acid, or combinations thereof; g) optionally, an additional stabilizing agent; and h) optionally, an agriculturally acceptable excipient.

[0138] Yet another embodiment of the present invention provides an agricultural composition comprising: a) a plant extract; b) a weak acid; c) a stabilizer; d) an amino acid or an amino acid source; e) a nutrient nanoparticle or a plurality of nutrient nanoparticles having a size range of about 1 nm to about 5000 nm, wherein the nutrient nanoparticle is a plant nutrient selected from nitrogen, its compounds or salts; phosphorus, its compounds or salts; potassium, its compounds or salts; or combinations thereof; f) optionally, a humic substance selected from humic acid, fulvic acid, or combinations thereof; g) optionally, an additional stabilizing agent; and h) optionally, an agriculturally acceptable excipient.

[0139] In an embodiment, the final composition obtained has a zeta potential in the range of about +20 mV to about -20 mV. In an embodiment, the final composition obtained has a zeta potential in the range of about +17 mV to about -17 mV. In an embodiment, the final composition obtained has a zeta potential in the range of about +15 mV to about -15 mV. In an embodiment, the final composition obtained has a zeta potential in the range of about +14 mV to about -14 mV.

[0140] In an embodiment, the particle size of resultant particles or nutrient particles or plurality of nutrient particles present in the composition ranges from about 1 nm to about 5,000 nm. In an embodiment, the particle size of resultant particles or nutrient particles present in the composition ranges from about 1 nm to about 4,000 nm. In an embodiment, the particle size of resultant particles or nutrient particles present in the composition ranges from about 1 nm to about 3,000 nm. In an embodiment, the particle size of resultant particles or nutrient particles present in the composition ranges from about 1 nm to about 2,000 nm. In an embodiment, the particle size of resultant particles or nutrient particles present in the composition ranges from about 1 nm to about 1,000 nm. In a preferred embodiment, the particle size of resultant particles or nutrient particles present in the composition ranges from about 1 nm to about 800 nm. In a preferred embodiment, the particle size of resultant particles or nutrient particles present in the composition ranges from about 10 nm to about 700 nm. In a preferred embodiment, the particle size of resultant particles or nutrient particles present in the composition ranges from about 10 nm to about 600 nm. In a preferred embodiment, the particle size of resultant particles or nutrient particles present in the composition ranges from about 20 nm to about 550 nm.

[0141] In an embodiment, the compositions of the present invention are stable and homogenous compositions, more particularly stable and homogenous nanofertilizer compositions. The compositions as disclosed in the present invention may be present in solid or liquid form. The compositions may be in form a solid, such as dusts, granules, water dispersible granules, dry flowables, powders, pellets, tablets, microcapsules, micro-complexes, and so forth. The compositions may be in form a liquid, such as a suspension concentrate, an emulsion, an oil dispersion, an emulsifiable concentrate, and so forth. The composition may be in form of a semi-solid, such as a gel, a paste, a cream, and so forth. In a preferred embodiment, the composition is a liquid composition.

[0142] In an embodiment, the compositions of the present invention have a pH in the range of about 4 to 9. It was observed that the composition ingredients and process were instrumental in producing a composition with said pH range and thus resulting in a stable, efficient composition. The pH of the composition plays an important role in the product stability, storage and efficacy.

[0143] In an embodiment, the composition comprises the nutrient particle or the nutrient nanoparticle in an amount ranging from about 1% w / w to about 60 % w / w of the total weight of the composition. In an embodiment, the composition comprises said nutrient particle or said nutrient nanoparticle in an amount ranging from about 1% w / w to about 50 % w / w of the total weight of the composition. In an embodiment, the composition comprises said nutrient particle or said nutrient nanoparticle in an amount ranging from about 1% w / w to about 40 % w / w of the total weight of the composition. In a preferred embodiment, the composition comprises said nutrient particle or said nutrient nanoparticle in an amount ranging from about 5% w / w to about 40 % w / w of the total weight of the composition. In a preferred embodiment, said nutrient particle or said nutrient nanoparticle is selected from urea or derivatives thereof, or diammonium phosphate.

[0144] In an embodiment, the composition comprises the nutrient particle or the nutrient nanoparticle in an amount ranging from about 1% w / v to about 60 % w / v of the total volume of the composition. In an embodiment, the composition comprises said nutrient particle or said nutrient nanoparticle in an amount ranging from about 1% w / v to about 50 % w / v of the total volume of the composition. In an embodiment, the composition comprises said nutrient particle or said nutrient nanoparticle in an amount ranging from about 1% w / v to about 40 % w / v of the total volume of the composition. In a preferred embodiment, said nutrient particle or said nutrient nanoparticle in an amount ranging from about 5% w / v to about 40 % w / v of the total volume of the composition. In a preferred embodiment, said nutrient particle or said nutrient nanoparticle is selected from urea or derivatives thereof, diammonium phosphate, or potash.

[0145] In an embodiment, the nitrogen content in the nutrient particle or the nutrient nanoparticle comprising nitrogen, or a combination of nitrogen and phosphorus ranges from about 5% w / w to about 85% w / w of the total weight of the compound.

[0146] In an embodiment, the nitrogen content in the nutrient particle or the nutrient nanoparticle comprising nitrogen, or a combination of nitrogen and phosphorus, ranges from about 5% w / v to about 85% w / v of the total volume of the compound.

[0147] In an embodiment, the phosphorus content in the nutrient particle or the nutrient nanoparticle comprising phosphorus, or a combination of phosphorus and nitrogen ranges from about 5% w / w to about 85% w / w of the total weight of the compound.

[0148] In an embodiment, the phosphorus content in the nutrient particle or the nutrient nanoparticle comprising phosphorus, or a combination thereof ranges from about 5% w / v to about 85% w / v of the total volume of the compound.

[0149] In an embodiment, the nitrogen content in the composition of the present invention ranges from about 1 % w / w to about 40 % w / w of the total weight of the composition. In a preferred embodiment, the nitrogen content in the composition of the present invention is in the range of about 4% w / w to about 6% w / w of the total weight of the composition.

[0150] In an embodiment, the nitrogen content in the composition of the present invention ranges from about 1 % w / v to about 40 % w / v of the total volume of the composition. In a preferred embodiment, the nitrogen content in the composition of the present invention is in the range of about 4% w / v to about 6% w / v of the total volume of the composition.

[0151] In an embodiment, the phosphorus content in the composition of the present invention ranges from about 1 % w / w to about 40 % w / w of the total weight of the composition. In a preferred embodiment, the nitrogen content in the composition of the present invention is in the range of about 4% w / w to about 6% w / w of the total weight of the composition.

[0152] In an embodiment, the phosphorus content in the composition of the present invention ranges from about 1 % w / v to about 40 % w / v of the total volume of the composition. In a preferred embodiment, the nitrogen content in the composition of the present invention is in the range of about 4% w / v to about 6% w / v of the total volume of the composition. In an embodiment, the composition comprises the plant extract in an amount ranging from about 5 %w / w to about 90 % w / w of the total weight of the composition. In an embodiment, the composition comprises the plant extract in an amount ranging from about 10 %w / w to about 85 % w / w of the total weight of the composition. In an embodiment, the composition comprises the plant extract in an amount ranging from about 15 %w / w to about 80 % w / w of the total weight of the composition. In an embodiment, the composition comprises the plant extract in an amount ranging from about 20 %w / w to about 75 % w / w of the total weight of the composition. In an embodiment, the composition comprises the plant extract in an amount ranging from about 25 %w / w to about 70 % w / w of the total weight of the composition.

[0153] In an embodiment, the composition comprises the plant extract in an amount ranging from about 5 %w / v to about 90 % w / v of the total volume of the composition. In an embodiment, the composition comprises the plant extract in an amount ranging from about 10 %w / v to about 85 % w / v of the total weight of the composition. In an embodiment, the composition comprises the plant extract in an amount ranging from about 15 %w / v to about 80 % w / v of the total weight of the composition. In an embodiment, the composition comprises the plant extract in an amount ranging from about 20 %w / v to about 75 % w / v of the total weight of the composition. In an embodiment, the composition comprises the plant extract in an amount ranging from about 25 %w / v to about 70 % w / v of the total weight of the composition.

[0154] In an embodiment, the composition comprises the stabilizer in an amount ranging from about 0.001%w / w to about 75% w / w of the total weight of the composition. In an embodiment, the composition comprises the stabilizer in an amount ranging from about 0.001%w / w to about 60% w / w of the total weight of the composition. In an embodiment, the composition comprises the stabilizer in an amount ranging from about 0.001%w / w to about 50% w / w of the total weight of the composition.

[0155] In an embodiment, the composition comprises the stabilizer in an amount ranging from about 0.001%w / v to about 75% w / v of the total volume of the composition. In an embodiment, the composition comprises the stabilizer in an amount ranging from about 0.001%w / v to about 60% w / v of the total volume of the composition. In an embodiment, the composition comprises the stabilizer in an amount ranging from about 0.00 l%w / v to about 50% w / v of the total volume of the composition.

[0156] In an embodiment, the composition comprises the additional stabilizing agent(s) in an amount ranging from about 0.001%w / w to about 40% w / w of the total weight of the composition. In an embodiment, the composition comprises the additional stabilizing agent(s) in an amount ranging from about 0.001%w / v to about 40% w / v of the total volume of the composition.

[0157] In an embodiment, the nitrogen content of the raw material form of nutrient particle is in the range of about 1% w / w to about 80% w / w of the total weight of the compound; and the particle size is 5 pm or greater.

[0158] In an embodiment, the particle size of the compositions of the present invention have been characterized by methods selected from transmission electron microscopy (TEM), Dynamic Light Scattering (DLS), or both. In a preferred embodiment, the particle size of the compositions of the present invention have been characterized by transmission electron microscopy (TEM). In a preferred embodiment, the particle size of the compositions of the present invention have been characterized by Dynamic Light Scattering (DLS).

[0159] In an embodiment, the zeta potential of a composition is analysed by an equipment capable of measuring zeta potential, such as a zetasizer. For example, Malvern Zetasizer may be used to measure the zeta potential of the composition of the present invention.

[0160] An embodiment of the present invention provides a method of growth stimulation in a plant or a part thereof, wherein the method comprises applying to the plant, a part thereof, or a locus a composition prepared by the process of the present invention.

[0161] An embodiment of the present invention provides a method of improving plant health and yield comprising applying to a plant or a part thereof, or a locus a stabilized agricultural composition prepared by the process of the present invention.

[0162] The plants for which the compositions prepared by the process of the present invention can be used are agronomically useful plants, for example for example vegetable, fruit and cereal crops, and ornamental plants. The agronomically useful plants are angiosperms selected from the group consisting of Apiaceae, Asteraceae, Brassicaceae, Chenopodiaceae, Convolvulaceae, Cucurbitaceae, Fabaceae, Gramineae, Liliaceae, Polygonaceae, Rosaceae, Solanaceae, Poaceae, the Vitaceae. Thus, in an embodiment, the plant is selected from crops, cereals, fruits, vegetables, nuts, vines, nursery plants and flowers. In an embodiment, non-limiting examples of plant include corn, cereals such as rice, wheat, barley, rye, oat, sorghum, millet, triticale, buckwheat, etc.; cotton, soybean, beet, row crops, legumes, grams, sugar cane, tobacco, etc.; oilseeds such as oilseed rape, peanut / groundnut, rapeseed, sunflower, etc.; vegetables: solanaceous vegetables such as eggplant, tomato, pimento, pepper, potato, etc., cucurbit vegetables such as cucumber, pumpkin, zucchini, water melon, melon, squash, gourds, muskmelon, etc., cruciferous vegetables such as radish, white turnip, horseradish, kohlrabi, cabbage, leaf mustard, broccoli, cauliflower, brussels sprouts, kale, etc., asteraceous vegetables such as burdock, crown daisy, artichoke, lettuce, etc, liliaceous vegetables such as green onion, onion, shallot, garlic, and asparagus, ammiaceous vegetables such as carrot, parsley, celery, parsnip, leek, etc., chenopodiaceous vegetables such as spinach, swiss chard, etc., lamiaceous vegetables such as Perilla frutescens. mint, basil, etc.; herbs and spices such as coriander, chamomile, cassia, catnip, clove, cumin, curry, cilantro, cinnamon, cardamom, dill, anise, juniper, lavender, parsley, rosemary, marigold, mustard, nutmeg, fennel, poppy, thyme, vanilla, saffron, poppy, sage, wintergreen, etc.; flowers, foliage plants, turf grasses, fruits: pome fruits such apple, pear, quince, guava, etc, stone fleshy fruits such as peach, plum, nectarine, cherry, apricot, prune, etc., citrus fruits such as orange, lemon, lime, grapefruit, mandarin, malta, kumquat, pummelo, tangerine, tangor, uniq, etc., nuts such as chestnuts, walnuts, hazelnuts, almond, pistachio, cashew nuts, macadamia nuts, pecan nut, cashew nut, hazel nut, pine nut, etc. berries such as caneberry, strawberry, blueberry, cranberry, blackberry, raspberry, coryberry, darrowberry, dewberry, thornless berry, evergreen blackberry, himalayaberry, hullberry, lavacaberry, loganberry, lowberry, lucretiaberry, mammoth blackberry, marionberry, mora, mures deronce, nectarberry, olallieberry, evergreen berry, phenomenalberry, rangeberry, ravenberry, rossberry, dewberry, tayberry, youngberry, zarzamora, aronia berry, currant, elderberry, barberry, gooseberry, honeysuckle, huckleberry, jostaberry, juneberry, lingonberry, salal, seabuckthorn, bayberry, buffaloberry, chokecherry, maypop, mulberry, bearberry, bilberry, cloudberry, muntries, partridgeberry, etc., grape, kaki fruit, kiwi fruit, olive, plum, banana, coffee, date palm, coconuts, papaya, persimmon, avocado, dragon fruit, pomegranate, lychee, jackfruit, pineapple, passionfruit, sapota, etc., trees other than fruit trees; tea, mulberry, flowering plant, trees such as ash, birch, dogwood, eucalyptus, Ginkgo biloba. lilac, maple, Querciis. poplar, Judas tree, Liquidambar formosana. plane tree, zelkova, 30olocasi arborvitae, fir wood, hemlockjuniper, Pinus, Picea. and Taxus cuspidate, etc., other crops such as chive, day lily, Elegans hosta, Fritillaria, gojiberry, okra, pea, hops, beans, guar, radish, amaranth, jute, fenugreek, lentils, chickpea, artichoke, rhubarb, licorice, sweet potato, Dioscorea japonica, 30olocasia, ornamental grasses (lawn turf, sod, etc.), varieties and cultivars thereof.

[0163] In an embodiment, the compositions according to the present invention are suitable for use in seed treatment. Solutions for seed treatment (LS), Suspoemulsions (SE), flowable concentrates (FS), powders for dry treatment (DS), water-dispersible powders for slurry treatment (WS), water-soluble powders (SS), emulsions (ES), emulsifiable concentrates (EC) and gels (GF) are usually employed for the purposes of treatment of plant propagation materials, particularly seeds.

[0164] An embodiment also provides a seed coated with the compositions prepared by the process of the present invention.

[0165] The compositions prepared by the process of the present invention as per an embodiment can be applied

[0166] • Pre-emergence

[0167] • Post-emergence

[0168] • Before sowing

[0169] • Pre-harvest

[0170] In an embodiment, the compositions prepared by the process of the present invention are applied before planting / sowing; at the time of sowing, germination, early leaf stage, early bloom stage, pre-bloom stage, full bloom stage, petal fall stage, swollen bud stage, bud break stage, post petal fall stage, post bud break stage, pre-bud break stage, full pistillate stage, post pollination stage, square formation stage, pegging stage, post-pegging stage, fruit set stage, early mid-bloom, greenup (post-dormancy) stage, bud set stage, etc; after flowering stage; harvest stage; and / or post-harvest. In an embodiment, the compositions of the present invention may be applied anytime throughout the growth stage as conventionally known to a person skilled in the art. The time of application depends on the plant or a part thereof to which the compositions of the present invention are applied; environmental conditions such as nutrient deficiency, biotic and abiotic stresses; type of application and the expected outcome or any other parameter known to a person skilled in the art. Applications can be made throughout the growth of the plant, one or more times a week.

[0171] In an embodiment, the composition prepared by the process of the present invention is applied directly and / or indirectly to the plant and / or to plant propagation material by drenching the soil, by drip application onto the soil, by soil injection, by dipping or by treatment of seeds.

[0172] The compositions prepared by the process of the present invention may be applied by dusting, spraying, granular application, seed pelleting / seed dressing, broadcasting, in furrow application, side dressing, spot application, ring application, root zone application, pralinage, seedling root dip, sett treatment, trunk / stem injection, padding, swabbing, root feeding, soil drenching, capsular placement, baiting, fumigation, banding, foliar application, basal application, space treatment, enclosed space fumigation and such other methods which may help prevent or control or eradicate the disease.

[0173] In a preferred embodiment, the compositions prepared by the process of the present invention are applied as a drench application, in-furrow application, soil, drip irrigation, soil injection, hydroponic application, capillary action application, root infiltration, or a foliar application. In an embodiment, the compositions of the present invention is applied as a seed treatment such as seed soak application, seed coating application, germination treatment; or a rooting / shooting dip treatment. The type of application is decided as per the plant or a part thereof to which the compositions of the present invention are applied, the outcome expected, and the time of application and any other conventional parameters as known to a person skilled in the art.

[0174] The present compositions can be applied by the use of conventional ground sprayers, granule applicators, watering (drenching), drip irrigation, spraying, atomizing, broadcasting, dusting, foaming, spreading-on, aerial methods of spraying, aerial methods of application, methods utilizing application using modern technologies such as, but not limited to, drones, robots, predosage device, a knapsack sprayer, a spray tank, a spray plane, or an irrigation system and by other conventional means known to those skilled in the art.

[0175] In an embodiment, the compositions prepared by the process of the present invention may be combined with or applied in association with one or more additional agrochemically active agents. The agrochemically active substance is selected from, but not limited to, fertilizers, mycorrhiza, micronutrients, macronutrients, acaricides, algicides, antifeedants, avicides, bactericides, bird repellents, chemosterilants, fungicides, herbicide safeners, herbicides, insect attractants, insect repellents, insecticides, mammal repellents, mating disruptors, molluscicides, nematicides, plant activators, plant-growth regulators, rodenticides, synergists, virucides, derivatives thereof, biological control agents, superabsorbent polymers and mixtures thereof.

[0176] In an embodiment, the compositions prepared by the process of the present invention may be combined with additional nanoparticle compositions of other macronutrients and micronutrients such as phosphorus, potassium, sulphur, metals, and minerals. In an embodiment, the compositions prepared by the process of the present invention are used for slow and sustained release of the nutrient particle. In an embodiment, the compositions prepared by the process of the present invention are used for quick release of the nutrient particle.

[0177] EXAMPLES

[0178] Example 1: Preparation of nanoparticle composition (comprising nitrogen 5% w / w) of urea

[0179] Dried and ground leaves of lotus and banana (in a ratio of 1 :9) were soaked in demineralized water for 4-8 hours followed by boiling at 100°C - 120°C for 1 hour and subsequently filtration to obtain a homogenous plant extract.

[0180] 600 mL of homogenous plant extract with a pH of 6-7 was mixed with 20 gm of citric acid and subjected to agitation at 500-2000 rpm to obtain a homogenous mixture having pH of 2.5.

[0181] 0.5 gm of chitosan was dissolved in the homogenous mixture of plant extract and citric acid and solubilized by agitating at 500-2000 rpm to obtain a homogenous mixture.

[0182] Yeast extract was prepared by fermenting a primary inoculum of Saccharomyces cerevisiae (yeast) for 24-96 hrs at 28-30°C. The fermentation media comprising yeast was subjected to heat killing and sonication process at 90°C for 1 hour. The fermentation media comprising heat-killed and sonicated yeast was filtered to obtain a cell-free homogenous yeast extract. The cell-free homogenous yeast extract was added to the homogenized composition comprising urea and plant extract and pH was reduced to 3.0 - 4.0. This mixture was subjected to ultra- sonification for 30 minutes to 4 hours, at 45-50°C.

[0183] 300 ml yeast extract was added to the homogenous mixture of plant extract, citric acid and chitosan followed by addition of 110 gm urea, 1.1 gm propylene glycol, 1.2 gm of polyethylene glycol sorbitan monolaurate to obtain a homogenous mixture in presence of stirring. pH was adjusted to 4.0 with sodium hydroxide and 1 gm of sodium salt of carboxymethyl cellulose was added to the homogenous mixture. 1 ml of dipropylene glycol solution of 1,2- benzisothiazolin-3-one was added to this homogenous mixture to obtain a final composition.

[0184] Final composition was agitated for about 4 to 5 hours at room temperature at 500-2000 rpm. After the completion of homogenization, the homogenized composition was filtered, and supernatant was separated to obtain the liquid composition comprising urea in form of nanoparticles.

[0185] The above composition was subjected to particle size analysis performed using Dynamic Light Scattering (DLS) and transmission electron microscopy (TEM). The sampling and testing were carried out using standard protocols and procedures as known to a person ordinarily skilled in the art. The particle size of urea nanoparticles was recorded to be in the range of 1 nm to 1000 nm. The Z-average (average size of a particle size distribution) was found to be 26.62 nm by Zeta sizer (Malvern Zetasizer). The TEM (Transmission Electron Microscopy) analysis revealed size in the range of 20-70 nm. Zeta potential of the final composition was analysed by Malvern Zeta sizer. The zeta potential was found to be +3.76 mV.

[0186] The pH of the final composition obtained is 4.2.

[0187] Table 1 : Composition comprising urea nanoparticles having a nitrogen content of 5% w / v A three-batch analysis was carried out for the composition of Example 1 prepared by the process described herein at 3 different occasions. The particle size and zeta potential for 3 batch was recorded as follows:

[0188] Table 2: 3-batch analysis of the composition prepared by process described in Example 1

[0189] Example 2: Preparation of nanoparticle composition (comprising nitrogen 13% w / W, phosphorus 5% w / w and potassium 4% w / w).

[0190] Plant Extract preparation:

[0191] Plant powder was prepared by crushing a mixture of dried leaves of banana, beetle vine and moringa combined in weight ratio 8: 1 : 1. 30-70 grams plant powder was mixed in 1 -liter demineralized water at room temperature to obtain 5% plant extract. Mixture was heated at 100 °C for 1 hour and allowed to cool at room temperature. After cooling, mixture / slurry was filtered by sparkler filter / Duo filter / muslin cloth to obtain homogenous plant extract. The total solid content in homogenous plant extract is < 1%.

[0192] Amino acid and fulvic acid mixture preparation:

[0193] Demineralized water without any extraneous materials was heated up to 50-60 °C. 50% - 60% fulvic acid powder and 50% to 45% amino acid powder is added to the heated water sequentially and the materials properly blended until complete dissolution. pH was be maintained in the range of 3-4. The resulting amino acid and fulvic acid mixture contains 1% fulvic acid and 2% amino acid. 200-250 grams of this mixture was used to make the nanofertilizer composition described below.

[0194] Preparation of nanofertilizer composition:

[0195] About 60 - 100 grams of citric acid was added to approximately 150 - 250 gms of homogenous plant extract under continuous stirring at 800 - 900 rpm for 10 to 15 minutes. The pH was checked using pH meter at this stage which is found to be 1.5-2.5. After the complete solubilization of citric acid, 0.1 - 1 gram chitosan was added into the homogenized mixture of plant extract and citric acid under 800-900 rpm and stirred for 1 hour to completely solubilize chitosan powder at pH 3.5 to 4.0 at room temperature condition. Amino acid and fulvic acid mixture - about 200-250 gms per litre - was added into the above homogenous mixture under same agitation speed for 10- 15 minutes. About 80-100 grams diammonium phosphate were added into the above mixture and homogenized for about 30-50 minutes, followed by addition of 50-100 grams commercial grade potassium chloride into the mixture under same speed (rpm) for about 10-20 minutes. After complete dissolution of potassium chloride, 200-300 grams urea was added into the mixture at 800 to 900 rpm agitation speed and allowed it to completely disperse for 10-20 minutes. 5-10 gram malic acid was added into the mixture to attain pH range 4 to 4.5. 1-5 grams polypropylene glycol was slowly added into the mixture under the highspeed agitation at 800 - 1500 rpm followed by addition of 1-5 gram polyethylene glycol monotridecyl ether phosphate (surfactant) into the mixture at same rpm to obtain a final product.

[0196] After obtaining the final product, preservative dipropylene glycol solution of 1,2- benzisothiazolin-3-one at 0.1 % was added into the mixture under agitation and the misture was further homogenized at 900 -1000 rpm for 5 hours. The homogenized mixture was filtered and subjected for various analytical parameters, such as particle size distribution, particle size, zeta potential, pH, viscosity, solubility, content, and density.

[0197] The above composition was subjected to particle size analysis performed using Dynamic Light Scattering (DLS) and transmission electron microscopy (TEM). The sampling and testing were carried out using standard protocols and procedures as known to a person ordinarily skilled in the art. The particle size of urea nanoparticles was recorded to be in the range of 1 nm to 1000 nm. The Z-average (average size of a particle size distribution) was found to be 367 nm.

[0198] Zeta potential of the final composition was analysed by Malvern Zetasizer. The zeta potential was found to be -3 mV.

[0199] The pH of the final composition obtained is 4.1

[0200] Table 3: Nanoparticle composition comprising nitrogen, phosphorous and potassium

[0201] A three-batch analysis was carried out for a composition prepared by the process described herein on 3 different ocassions. The particle size and zeta potential for 3 batch was recorded as follows: Table 4: 3-batch analysis of the composition prepared by process described in Example 2

[0202] Example 3: Nanoparticle composition comprising nitrogen, phosphorous and potassium

[0203] The process as described in Example 2 was carried out to develop a composition as depicted in table 5. Table 5: Nanoparticle composition comprising nitrogen, phosphorous and potassium Example 4: Nanoparticle composition comprising nitrogen, phosphorous and potassium

[0204] The process as described in Example 2 was carried out to develop a composition as depicted in table 6.

[0205] Table 6: Nanoparticle composition comprising nitrogen, phosphorous and potassium

Claims

We claim:

1. A process of preparing an agricultural fertilizer composition, said process comprising:A. providing a homogenous solution of a plant extract;B. solubilizing in the homogenous solution of the plant extract a weak acid;C. adding a stabilizer to the solution of step B and solubilizing to obtain a homogenous solution;D. adding and solubilizing an amino acid or an amino acid source to homogenous solution obtained in step C; andE. mixing the raw material form of a nutrient particle, or a plurality of raw material forms of nutrient particles in the homogenous solution obtained in step D to obtain a final composition, wherein the nutrient particle or the plurality of nutrient particles is / are a plant nutrient selected from nitrogen, its compounds or salts; phosphorus, its compounds or salts; potassium, its compounds or salts; or combinations thereof.

2. The process as claimed in claim 1, wherein the final composition obtained has a zeta potential in the range of about +20 mV to about -20 mV.

3. The process as claimed in claim 1, wherein the particle size of resultant particles or nutrient particles or plurality of nutrient particles present in the final composition ranges from about 1 nm to about 5,000 nm.

4. The process as claimed in claim 1, wherein said process is characterized by absence of energy expenditure.

5. The process as claimed in claim 1, wherein the final composition is stable and homogenous.

6. The process as claimed in claim 1, wherein said nutrient particle or the plurality of nutrient particles are selected froma. a nitrogen-containing plant nutrient or a nitrogen-containing fertilizer such as those selected from the group consisting of urea or salts or derivatives thereof (carbamide), ammonium compounds, ammonium fertilizer, urea ammonium nitrate (UAN), cyanamide, guanidine nitrate, dicyandiamide (DCD), guanyl urea sulphate, thiourea, urea formaldehyde polymer, amino acids, amines, amino alcohols, amides, lactams, nitro compounds, imines, nitriles, diazonium salts, hydrazides, carbazides, oximes, alkyl nitrates, nitrosamines, nitroarenes, peroxyacyl nitrates and heterocyclic compounds such as imidazole, triazole, and tetrazole and salts or derivatives thereof; b. a potassium-containing plant nutrient or a potassium-containing fertilizer selected from potassium chloride, potash, muriate of potash or combinations thereof; c. a phosphorus-containing plant nutrient or a phosphorus-containing fertilizer selected from ammonium phosphate, diammonium phosphate (DAP), monoammonium phosphate (MAP), and combinations thereof; or a combination of any or all of a, b and c.

7. The process as claimed in claim 1, wherein the plant extract is an extract of a plant, or a part of plant selected from the group consisting of genera Nelumbo, Musa, Moringa, Citrus, Brassica, Avena, Cymbopogon, Piper, Tamarindus, Aloe, Phyllanthus, Capsicum, Zea, Mangifera, Solanum, Eucalyptus, Syzygium, Psidium, Elaeocarpus, and combinations thereof.

8. The process as claimed in claim 1, wherein the weak acid is selected from the group consisting of citric acid, malic acid, lactic acid, formic acid, acetic acid, benzoic acid, carbonic acid, and salts or derivatives thereof.

9. The process as claimed in claim 1, wherein the stabilizer is a poly cation polymer selected from polyamidoamine, polyethylenimine, mannosylated polyethylenimine, chitosan, chitosan derivatives, poly(allylamine), poly(l-lysine), poly(dimethyldiallylammonium chloride), and poly(allylamine hydrochloride); or combinations thereof.

10. The process as claimed in claim 1, wherein the amino acid source is an extract comprising an amino acid and wherein said extract is selected from microbial extracts, vegetable extracts, or combinations thereof.

11. The process as claimed in claim 10, wherein said microbial extract is a yeast extract.

12. The process as claimed in claim 1, wherein said process further comprises adding an additional stabilizing agent(s) to the final composition.

13. The process as claimed in claim 12, wherein said additional stabilizing agent(s) comprise a pH stabilizer.

14. The process as claimed in claim 13, wherein the final composition has a pH in the range of about 4 to 9.

15. An agricultural fertilizer composition obtainable by the process as claimed in claim 1.

16. The agricultural fertilizer composition as claimed in claim 15, wherein the composition is characterized by absence of gas generation and crystallization during storage.

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