Composition comprising NANO-particulate fertilizer and process thereof for improved plant growth and yield

Abstract

The present invention relates to a process of preparing composition comprising nano- particulate fertilizer which provides enhanced bioavailability to soil and plants via slow-release mechanism, enhanced utilization by the plants and crops.

Description

[0001] COMPOSITION COMPRISING NANO-PARTICULATE FERTILIZER AND

[0002] PROCESS THEREOF FOR IMPROVED PLANT GROWTH AND YIELD

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to a process of preparing composition comprising Nanoparticulate fertilizer which provides enhanced bioavailability to soil and plants with slow- release mechanism, enhanced utilization by the plants and crops. This invention also relates to sustainable, cost-effective, scalable method of manufacturing of Nano- particulate fertilizer composition comprising nitrogen and which employs jet- milling of raw materials using milling equipment for reduction of particulates. The present invention further relates to the physicochemical processing of the ingredients in a suitable composition and composition thereof. Thus, the present invention also relates to nano-particulate fertilizer composition for slow-release mechanism, enhanced utilization by the plants, enhanced nutrient uptake, plant growth, development and protection from biotic and abiotic stress.

[0005] BACKGROUND OF THE INVENTION

[0006] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention.

[0007] Fertilizers are used as supplement and as conditioner for the soil and crops to facilitate high yield and improved fertility. Conventional chemical fertilizers have many disadvantages including less or no absorption and deterioration of soil quality with prolonged usage. Traditional urea-based fertilizers also have been widely used in agricultural industry to provide essential nitrogen nutrients to crops. Traditional urea-based fertilizers often suffer from significant drawbacks such as inefficient nutrient utilisation, susceptible to leaching, volatilization and uneven distribution of nutrients. Hence, there remains a need for improvement in fertilizer compositions to provide essential plant nutrients, in particular, nitrogen, for agricultural application without causing or limiting environmental hazard but has improved stability for use over sustained period for continuous nitrogen uptake by plants.

[0008] Nano fertilizers are prepared by incorporating plant nutrients in the form of nanomaterials, using a small amount of nanomaterial coating on plant nutrients, and delivering in the forms of nano emulsions. Among the mineral nutrients, nitrogen in the form of urea is the first and most important nutrient applied to plants. Nitrogen plays a key role in plant life cycle as it is a source of chlorophyll and many proteins and enzymes. Nitrogen is abundant in the atmosphere which is not available to plants. It is absorbed by plants in the form of nitrate (NCh ) and ammonium (NH4+). Nitrogen is lost through nitrate leaching processes, denitrification and ammonia volatilization. Loss of mineral nutrients through leaching and surface and groundwater flows and high wind intensity is causing growing concern due to economic losses and soil pollution. Nano encapsulation also provided encouraging results to improve fertilizer efficiency with significant reductions inactive ingredients.

[0009] In recent years, researchers have explored the use of nanotechnology to address the limitation of conventional fertilizers. Various Nano-fertilizer compositions have been proposed, aiming to improve nutrient release and absorption, less environmental pollution. However, several of these existing processes to manufacture Nano fertilizers suffers from practical challenges and complexity. One of the common problems associated with these existing processes is their complexity like involving use of complex carbohydrate polymers and their hydrolysis, high cost and low yield, efficacy of the final product which hinders its industrial scale production and commercialization. Some of such prior art nano -fertilizer compositions and their process of preparation as mentioned herein below:

[0010] W02009121501A2 discloses particles, obtained by drying an aqueous nanourea dispersion and obtained an aqueous polyurea dispersion of crosslinked nanourea particles by drying for the production of cosmetics. The problem statement in relation to this prior art pertains to the cosmetics prepared with use of the crosslinked nano urea material which does not have any application in the agriculture field. Also, the stability of the material formed with the process used therein if used with the aqueous media, is not confirmed.

[0011] IN202122043098 relates to a method of manufacturing of nano urea using urea for slow release, enhanced utilization by the plants and application thereof. The said patent application discloses the method of manufacturing Nano Urea using urea and / or ammonia as precursor in the form of solid, liquid or aerosol. The bottom-up fabrication approach allows the size and other nanoscale properties controlled stable clusters using organic (oligo and polymer units) substrates. From the agrochemical perspective, Nano Urea can be applied to plants by foliar application, root drenching or by amending with soil. The process for preparation of Nano-urea in this prior art entails use of oligosaccharides whereas the present invention differs in the manufacturing process and the specific ingredients, additives used therein along with specific process steps, which renders the present invention as novel and inventive in so far as the process and product as nano-particulate fertilizer containing composition is concerned.

[0012] Therefore, there is a need for improvement in fertilizer compositions containing nano-urea as source of nitrogen and their preparation process which are cost-effective, scalable, easy to manufacture at industrial scale and having enhanced efficacy by way of increased utilisation and bioavailability of nano-particulate fertilizer to soil and plants.

[0013] The novel and inventive manufacturing process, nano particulate fertiliser and its composition thereof allows manufacturing of nitrogen at nanoscale which has enhanced use efficacy by way of increased utilisation and bioavailability with slow-release mechanism. Furthermore, this composition comprising Nano-particulate fertilizer can be applied to the plants, both by foliar and root exposure.

[0014] The process and composition of the present invention involves high speed shearing and jetmilling to produce nano-particles of urea and overcomes the limitations of prior art processes which involved hydrolysis of carbohydrate polymers made of glucose units.

[0015] In summary, the present invention discloses improved method for the manufacturing of composition comprising nano particulate fertiliser of nitrogen as nano urea. The final product is stable and scalable at the industrial scale which meets the objective of increasing crop production using eco-friendly agrochemicals. Further, the desired colloidal stability and particle size of the nano-fertilizer composition is achieved through physicochemical processing of the process of present invention. Further, the use of specific ingredients including but not limited to monosaccharides and / or additives increase the zeta potential and thereby improves the colloidal stability of the said composition comprising nano particulate fertiliser.

[0016] Additionally, urease inhibitors and / or nitrification inhibitors and / or growth hormones are also added in the composition of present invention, which reduce the conversion of urea to undesired products thereby increasing the uptake / utilization of urea by the plants / crops, and thus higher crop yield is obtained

[0017] The composite nanoscale particles of the nano particulate fertiliser composition of the present invention can be dispersed in water, in soil or other similar inorganic / organic media to develop liquid and / or solid formulation, pellet, powder, granule, film, and / or coating on seed surface with or without any dispersing agents. Further, the composition of the present invention can be applied on seed surface as coating, basal application for root exposure and foliar application for leaf exposure.

[0018] OBJECTIVES AND ADVANTAGES OF THE INVENTION

[0019] The main objective of the present invention is to provide nitrogen to plants / crops with use of nano-particulate fertilizer composition which is eco-friendly, cost effective, with no or minimal pollution, is stable and scalable at the industrial scale with reduced wastage of urea, thus providing single solution for plant growth nutrition in a slow-release mechanism.

[0020] Another objective of the present invention is to provide slow-release formulation / composition of nitrogen and its manufacturing process which increases soil fertility and plant growth as the required nitrogen content is released slowly with embodiment of urea in nano-colloidal form.

[0021] Another objective of the present invention is to provide a process of preparing the nanoparticulate fertilizer composition which provides enhanced bioavailability to soil and plants including cereals, fruit trees, and vegetables.

[0022] Another objective of the present invention is to provide a process of preparing the nanoparticulate fertilizer composition which provides better crop, fruit yield.

[0023] Another objective of the present invention is to provide a process of preparing the nanoparticulate fertilizer composition which is economical.

[0024] Another objective of the present invention is to provide a process of preparing the nanoparticulate fertilizer and its composition, which reduces the conversion of urea to undesired products.

[0025] Another objective of the present invention is to provide process for preparation of nanoparticulate fertilizer composition and composition thereof, having high surface area and volume ratio.

[0026] Another objective of the present invention is to provide nano- particulate fertilizer composition having nitrogen content in the range of 0.5 % to 47 % of the composition

[0027] Yet another objective of the present invention is to provide nano- particulate fertilizer composition which is prepared using the jet- milling method and physicochemical processing of the ingredients.

[0028] Yet another objective of the present invention is to provide nano- particulate fertilizer composition having particle size range from 10 nm to 50 microns. Yet another objective of the present invention is to provide nano- particulate fertilizer composition having better or enhanced colloidal stability.

[0029] Yet another objective of the present invention is to provide nano- particulate fertilizer composition with improved zeta potential value in the range of +120 to -120 mV.

[0030] Yet another objective of the present invention is to provide nano- particulate fertilizer composition with improved zeta potential value in the range of +40 to -40 mV.

[0031] Yet another objective of the present invention is to provide nano- particulate fertilizer composition with improved hydrodynamic size.

[0032] Yet another objective of the present invention is to provide nano- particulate fertilizer composition which provides increased uptake of nutrients especially nitrogen by the plants, crops.

[0033] Yet another objective of the present invention is to provide nano- particulate fertilizer composition which provides better and increased crop and / or fruit yield.

[0034] ADVANTAGES OF THE PRESENT INVENTION

[0035] • The present invention provides nano-particulate fertilizer composition having increased zeta potential and thereby improved the colloidal stability of the said nano-particulate fertilizer composition.

[0036] • The present invention provides nano- particulate fertilizer composition having increased efficacy and bio-availability.

[0037] • The nano-particulate fertilizer composition of present invention provides reduced conversion of urea to undesired products and thereby increasing the uptake / utilization of urea by the plants / crops, and thereby higher crop yields.

[0038] • Use of mono- saccharides and / or disaccharides in the present invention avoids the step of hydrolysis of polymers, which make the process of present invention, more cost effective, economical for large scale industrial production with higher yield.

[0039] • The present invention provides nano- particulate fertilizer composition having improved dispersion stability.

[0040] • The present invention provides nano- particulate fertilizer composition which provides reduced loss of ammonia from urea.

[0041] • The present invention provides nano- particulate fertilizer composition which provides reduced conversion of ammonia to nitrate thereby reducing urea loss. The present invention provides nano- particulate fertilizer composition which provides better plant / crop growth.

[0042] SUMMARY OF THE INVENTION

[0043] The present invention provides a process for preparing nano- particulate fertilizer composition which provides enhanced bioavailability to soil and plants including cereals, fruit trees, and vegetables via the controlled and extended release of nano particulate fertilizer.

[0044] The present invention provides a nano- particulate fertilizer composition which provides enhanced bioavailability to soil and plants including cereals, fruit trees, and vegetables via the controlled and extended release.

[0045] The present invention further relates to specific weight ratio / proportion of urea with monosaccharides and / or disaccharides which has led to improved colloidal stability and particle size of the nano-particulate fertilizer composition.

[0046] The present invention further relates to the use of various additives and / or reagents for achieving optimal depletion stability and dispersion stability.

[0047] The present invention further relates to the use of various additives including specific additives such as nitrification inhibitor, urease inhibitor, growth hormone, or combinations thereof

[0048] In one aspect of the present invention, the ratio of urea to monosaccharide is 0.5 to 15.

[0049] In one another aspect of the present invention, monosaccharides are selected from but not limited to glucose, dextrose, fructose, and galactose or combination / mixture thereof.

[0050] In one another aspect of the present invention, disaccharides are selected from but not limited to lactose, maltose, and sucrose or combination / mixture thereof.

[0051] In one another aspect of the present invention, additives are selected from the group comprising Polyvinyl pyrrolidinone (PVP), polyvinyl alcohol (PVA), Polyacrylic acid(PAA), Polyethylene glycol(PEG), N,N-Bis (Phosphonomethyl)glycine, Trisodium citrate, ethylene diamine tetra-acetic acid (EDTA) , nitrification inhibitor, urease inhibitor, growth hormone, or combinations thereof and are present in the range of 0.5 to 20 % by weight of the composition.

[0052] In one another aspect embodiment of the present invention, nitrification inhibitor is selected from the group comprising [ 2-chloro-6-(trichloromethyl) pyridine (nitrapyrin), dicyandiamide (DCD), and 3,4-dimethyl pyrazole phosphate (DMPP) or combinations thereof and present in the range of 0.5 to 5 % by weight of the total composition.

[0053] In one another preferred aspect of the present invention, urease inhibitor is selected from the group comprising N-(n-butyl) thiophosphoric triamide (NBPT) and N-(n-propyl) thiophosphoric triamide (NPPT) or combinations thereof and is present in the range of 0.5 to 5% by weight of the total composition.

[0054] In one another preferred aspect of the present invention, growth hormones are selected from the group comprising Auxins, Gibberellins, and Cytokinins and are present in the range of 0.5 to 5 % by weight of the total composition.

[0055] In one another aspect of the present invention provides a process for preparation of nanoparticulate fertilizer composition, which process comprises the multiple steps, and not necessarily restricted to the listed sequence: a) Jet-milling of monosaccharides or di- saccharides and urea powder using milling equipment, b) preparing solution of urea, preparing solution of monosaccharide or di-saccharide by dissolving monosaccharides or di-saccharides in 5 L Teflon coated reactor using specially designed agitators at high speed, stirring the solution at high speed with inorganic acid selected from but not limited to Hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, nitrous acid and organic acid selected from but not limited to acetic acid, ethanoic acid, propanoic acid, isobutyric acid at elevated temperature for a day, c) Neutralizing the above solution by adding bases like ammonia gas or different solid base, filtering the solution and distilling out the water for complete dryness, transferring to the reactor, adding drop-wise the solution of the urea, stirring with specially designed agitator at high speed. d) Adjusting pH of the solution with inorganic acid selected from but not limited to Hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, nitrous acid and organic acid selected from but not limited to acetic acid, ethanoic acid, propanoic acid, isobutyric acid. Physico-chemical processing of ingredients and solution obtained. e) Addition of additives by stirring at high speed. f) Subjecting the composition to centrifugal machine. g) Analysing the portion of the composition for particle size, Zeta potential, and other analyses.

[0056] In one further alternate aspect of the present invention, a process for preparation of a nanoparticulate fertilizer composition is provided, comprising the following steps: a) Jet milling of saccharides and urea; b) Preparing a saccharide solution; c) Addition of organic or inorganic acid to saccharide solution followed by heating at a temperature range 100-120°C and then neutralizing the solution by addition of neutralizing agent to obtain a neutralized solution; d) Preparing a solution of urea; e) Dropwise addition of urea solution to the saccharide solution to obtain a mixture; f) Addition of additives to the mixture obtained in step d) followed by stirring, obtain nanoparticulate fertilizer composition.

[0057] In one another aspect of the present invention, additives of the present composition are added in the range of 0.5 to 20 % by weight of the total composition.

[0058] DETAILED DESCRIPTION OF THE INVENTION

[0059] Discussed below are some representative embodiments of the present invention. The invention in its broader aspects is not limited to the specific details and representative methods. The illustrative examples are described in this section in connection with the embodiments and methods provided. The present application is not intended to be limited to the embodiments shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.

[0060] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed method and compositions belong. It must be noted that as used herein, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, reference to “a additives” includes “one or more” additives or a “plurality” of such additives.

[0061] As used herein, the term “Nano-particulate fertilizer” is a uniform collection of nanoparticles. Nano-particulate fertilizer could contain nanoparticles having diameters in a range from 1 nm to 1000 nm, 5 nm to 500 nm, 5 nm to 300 nm, 5 nm to 100 nm, 5 nm to 50 nm or below 5 nm. The nano-particulate fertilizer composition could also have a bi-modal size distribution where some particles could lie in a range of 5-50 nm and remaining could lie in the range of 50 nm to 1000 nm.

[0062] In one embodiment of the present invention, it provides a process for preparation of nanoparticulate fertilizer composition, which comprises multiple steps, and not necessarily restricted to the listed sequence: a) Jet-milling of monosaccharides or di- saccharides and urea powder using milling equipment, b) preparing solution of urea, preparing solution of monosaccharide or di-saccharide by dissolving monosaccharides or di-saccharides in 5 L Teflon coated reactor using specially designed agitators at high speed, stirring the solution at high speed with inorganic acid selected from but not limited to Hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, nitrous acid and organic acid selected from but not limited to acetic acid, ethanoic acid, propanoic acid, isobutyric acid at elevated temperature for a day, c) Neutralizing the above solution by adding bases like ammonia gas or different solid base, filtering the solution and distilling out the water for complete dryness, transferring to the reactor, adding drop-wise the solution of the urea, stirring with specially designed agitator at high speed. d) Adjusting pH of the solution with inorganic acid selected from but not limited to Hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, nitrous acid and organic acid selected from but not limited to acetic acid, ethanoic acid, propanoic acid, isobutyric acid. Physico-chemical processing of ingredients and solution obtained. e) Addition of additives by stirring at high speed. f) Subjecting the composition to centrifugal machine. g) Analysing the portion of the composition for particle size, Zeta potential, and other analyses.

[0063] In one further alternate embodiment of the present invention, a process for preparation of a nano-particulate fertilizer composition, comprising the following steps and not necessarily restricted to the listed sequence: a) Preparing a saccharide solution; b) Addition of organic or inorganic acid to saccharide solution followed by heating at a temperature range 100-120°C and then neutralizing the solution by addition of neutralizing agent to obtain a neutralized solution; c) Preparing a solution of urea; d) Dropwise addition of urea solution to the saccharide solution to obtain a mixture; e) Addition of additives to the mixture obtained in step d) followed by stirring, to obtains nanoparticulate fertilizer composition.

[0064] In one further alternate embodiment of the present invention, a process for preparation of a nano-particulate fertilizer composition is provided which comprises multiple steps, and not necessarily restricted to the listed sequence: a) Jet milling of saccharides and urea; b) Preparing a saccharide solution; c) Addition of organic or inorganic acid to saccharide solution followed by heating at a temperature range 100-120°C and then neutralizing the solution by addition of neutralizing agent to obtain a neutralized solution; d) Addition of additives to the neutralized solution followed by stirring, e) Filtering the solution and distilling out the water for complete dryness f) Preparing a solution of urea; g) Dropwise addition of urea solution to the saccharide solution to obtain a mixture; h) Ultracentrifugation of the obtained mixture to furnish nano-particulate fertilizer composition.

[0065] In one another embodiment of the present invention, the nano -particulate fertilizer composition comprises solution of a) urea; b) saccharide; c) additives.

[0066] In one another embodiment of the present invention, the ratio of urea to saccharides is 0.5 to 15. In one another embodiment of the present invention, the saccharides are either monosaccharides and disaccharides or combination / mixture thereof.

[0067] In one another embodiment of the present invention, the monosaccharides are selected from the group comprising glucose, dextrose, fructose, and galactose or mixtures thereof.

[0068] In one another embodiment of the present invention the disaccharides are selected from the group comprising lactose, maltose, and sucrose or mixtures thereof.

[0069] In one another embodiment of the present invention the organic acid is selected from the group comprising acetic acid, ethanoic acid, propionic acid, isobutyric acid or mixtures thereof.

[0070] In one another embodiment of the present invention the inorganic acid is selected from the group comprising Hydrochloric acid, sulfuric acid, phosphoric acid (orthophosphoric acid,), nitric acid, nitrous acid or mixtures thereof.

[0071] In one another embodiment of the present invention, the additives are selected from the group comprising Polyvinyl pyrrolidinone(PVP), polyvinyl alcohol(PVA), Polyacrylic acid, Polyethylene glycol, N,N-Bis (Phosphonomethyl)glycine, Trisodium citrate, ethylene diamine tetra-acetic acid, nitrification inhibitor, urease inhibitor, growth hormone or combinations thereof and are present in the range of 0.5 to 20 % by weight of the composition.

[0072] In one another embodiment of the present invention, the nitrification inhibitor(s) is selected from the group comprising 2-chloro-6-(trichloromethyl) pyridine (nitrapyrin), dicyandiamide (DCD), and 3,4-dimethyl pyrazole phosphate (DMPP) or combinations thereof and is present in the range of 0.5 to 5 % by weight of the total composition.

[0073] In one another embodiment of the present invention, the urease inhibitor(s) is selected from the group comprising N-(n-butyl) thiophosphoric triamide (NBPT) and N-(n-propyl) thiophosphoric triamide (NPPT) or combinations thereof and is present in the range of 0.5 to 5% by weight of the total composition.

[0074] In one another embodiment of the present invention, the growth hormone(s) are selected from the group comprising Auxins, Gibberellins, and Cytokinins and are present in the range of 0.5 to 5 % by weight of the total composition.

[0075] In a further preferred embodiment, nano-particulate fertilizer composition has Zeta potential in the range of +120 to -120 mV. In one another preferred embodiment, nano-particulate fertilizer composition has Zeta potential in the range of +40 to -40 mV.

[0076] In yet another embodiment, of the present invention, the nano-particulate fertilizer composition further comprises macronutrients and / or micronutrients.

[0077] The embodiments of the present invention are more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those of skill in the art. Unless otherwise noted, all parts, percentages and ratios reported in the following examples are on a weight basis and all reagents used in the examples were obtained or are available from the chemical suppliers.

[0078] In one another embodiment of the present invention provides a process for preparation of nanoparticulate fertilizer composition comprises the multiple steps, which are not restricted to the listed sequence but may be adjusted and hence not restricted to the specified sequence.

[0079] Milling of Dextrose, Sucrose and urea was done separately using milling equipment and were used for preparing the various nano urea composition as described below.

[0080] Example 1: To a Teflon coated SS reactor (5 Lit) fitted with specially designed Teflon coated mechanical agitator, reflux condenser, thermometer pocket, and thermometer, Dextrose (50 gm) and distilled water (950 gm) were added. This mixture was stirred for 30 minutes at high speed. To this, concentrated hydrochloric acid (150 gm, 35 %) was added slowly. The solution was heated at 100-110 ° C for a day. The mixture was cooled to room temperature slowly by stepwise cooling. The solution was filtered. The filtrate was neutralized by passing ammonia gas or by adding solid base carefully without rise of the temperature. After neutralization, water was distilled out to dryness. This material is transferred to the same reactor. Urea (250 gm) was dissolved in distilled water (950 gm) was added dropwise over 1 hour. This solution was stirred for 4 hours at high speed. The pH of the solution was adjusted by addition of glacial acetic acid followed by addition of 1 % Trisodium Citrate (Additive 1). The composition was stirred for 1 hour at high speed, followed by addition of 1 % Ethylenediaminetetraacetic acid (EDTA) (Additive 2). After stirring at high speed for 1 hour, 1 % polyvinyl alcohol (PVA) (Additive 3), were added. The composition was stirred for 1 h thereafter at the same high speed. The portion of the composition was analysed and, the results obtained are summarized in Table 4.. Example 2: To a Teflon coated SS reactor (5 Lit) fitted with Teflon coated mechanical agitator, reflux condenser, thermometer pocket, and thermometer, Dextrose (50 gm) and distilled water (950 gm) were added. This mixture was stirred for 30 minutes at high speed. To this, Acetic acid (225 gm) was added slowly. The solution was heated at 100-110 °C for a day. The mixture was cooled to room temperature slowly by stepwise cooling. The solution was filtered. The filtrate was neutralized by passing ammonia gas or by adding solid base carefully without rise of the temperature. After neutralization, water was distilled out to dryness. This material is transferred to the same reactor. Urea (250 gm) dissolved in distilled water (950 gm) was added dropwise over 1 hour. This solution was stirred for 4 hours at high speed. The pH of the solution was adjusted by addition of glacial acetic acid followed by addition of 1 % Trisodium Citrate (Additive 1). The composition was stirred for 1 hour at high speed, followed by addition of 1 % Ethylenediaminetetraacetic acid (EDTA) (Additive 2). After stirring at high speed for 1 hour, 1 % polyvinyl alcohol (PVA) (Additive 3), were added. The composition was stirred for 1 h thereafter at the same high speed. The portion of the composition was analysed and, the results obtained are summarized in Table 4.

[0081] The following compositions of Examples 3-29 were made by using analogous procedure described above in Example 1 and 2

[0082] Table 1: Examples 3-29

[0083] Example 30: To a Teflon coated SS reactor (5 Lit) fitted with mechanical agitator, reflux condenser, thermometer pocket, and thermometer, Dextrose (120 gm) and distilled water (280 gm) were added. This mixture was stirred for 30 minutes at high speed. To this, orthophosphoric acid (170 gm, 88 %) was added slowly. The solution was heated at 100-1100C for a day. The mixture was cooled to room temperature slowly by stepwise cooling. The solution was filtered. The filtrate was neutralized by passing ammonia gas or by adding solid base carefully without rise of the temperature. After neutralization, water was distilled out to dryness. This material is transferred to the same reactor. Urea (1200 gm) dissolved in distilled water (1100 gm) was added drop wise over 1 hour. This solution was stirred for 4 hours at high speed. The pH of the solution was adjusted by addition of glacial acetic acid followed by addition of 0.5 % Trisodium Citrate (Additive 1), and 0.5 % Ethylenediaminetetraacetic acid (EDTA, Additive 2). After stirring for 4 hrs, 0.5 % polyvinylpyrrolidone (Additive 3), was added. The composition was stirred for 4 hrs thereafter at the same high speed. The portion of the composition was analysed and, the results obtained are summarized in Table 4...

[0084] The following compositions of example 31-35 were made by using analogous procedure described above in Example 30

[0085] Table 2: Example 31-35

[0086]

[0087] Example 36: To a Teflon coated SS reactor (5 Lit) fitted with Teflon coated mechanical agitator, reflux condenser, thermometer pocket, and thermometer, Sucrose (50 gm) and distilled water (950 gm) were added. This mixture was stirred for 30 minutes at high speed. To this, concentrated Sulfuric acid (38 gm, 98 %) was added very carefully. The solution was heated at 100-1100C for a day. The mixture was cooled to room temperature slowly by stepwise cooling. The solution was filtered. The filtrate was neutralized by passing ammonia gas or by adding solid base carefully without rise of the temperature. After neutralization, water was distilled out to dryness. This material is transferred to the same reactor. Urea (250 gm) dissolved in distilled water (950 gm) was added dropwise over 1 hour. This solution was stirred for 4 hours at high speed. The pH of the solution was adjusted by addition of glacial acetic acid followed by addition of 0.5 % Trisodium citrate, (Additive 1) followed by 0.5 % Ethylenediaminetetraacetic acid (EDTA). After stirring for 4 hrs, 0.5 % polyvinylpyrrolidone K-90 (PVP K-90) (Additive 3), was added. The composition was stirred for 4 hrs thereafter at the same high speed. The portion of the composition was analysed and, the results obtained are summarized in Table 4 .

[0088] The following compositions of Example 37-41 were made by using analogous procedure described above in Example 36.

[0089] Table 3: Example 37-41

[0090]

[0091] Table 4

[0092] *ND=not determined

[0093] Example 42: Determination of Urea release For measuring urea release, 5 g of nano fertilizer particulate composition was diluted with distilled water (95 gm) to 100 gm in a glass bottle and stored in oven at 30° C. At specific time intervals 5 mL sample solution was taken out for HPLC analysis. The sample solution was filtered through 0.22 pm filter and injected into the HPLC system. By comparing the urea peak and calibration curve, the urea concentration of the sample solution could be determined.

[0094] To prepare the calibration curves, standard urea was dissolved in water to obtain two stock solutions with concentrations of 1000 ppm and 10,000 ppm. Two sets of standard urea solutions were prepared for plotting the calibration curves.

[0095] The % of urea released is calculated using the formula;

[0096] % cumulative release of urea = Mreiease / Mtotai release X 100

[0097] Wherein Mreiease is the weight of urea released in aqueous solution at specific time point and Mtotai release is the maximum weight of urea released in aqueous solution.

[0098] To determine the Mtotai release, water from the nano fertilizer particulate composition was removed completely to obtain solid. This solid was ground to fine powder if required and then dissolved in water. The concentration of the urea in the solution was determined using HPLC.

[0099] Table 5: Measuring urea release from nano fertilizer particulate composition

[0100] Example 43: Effect of Nano Urea on Crops

[0101] Effectiveness of Nano Urea formulation / compo sition or nano fertilizer particulate of present invention, as a potential fertilizer is evaluated during field trials on OKRA crop at Kalyani, West Bengal, India. However, the claimed efficacy is not limited to the crop and can be applied on any crop as a Nitrogen source.

[0102] The treatment particulars and details are summarized in table 6 below.

[0103] Table 6: The preliminary results of the field trial are summarized in Table 7 below.

[0104] Table 7:

[0105] Table 8

[0106] Comparative Table below illustrates the hydrodynamic size and Zeta potential value of nanoparticulate fertilizer composition of the present invention versus product already known in the prior art / market.

[0107] From the above tables, it is clearly evident that the nano particulate fertilizer composition of the present invention exhibits a higher zeta potential value compared to the prior art product(s). A higher zeta potential value, signifies enhanced stability of the composition due to the increased electrostatic repulsion between particles, which prevents aggregation. Additionally, the nano particulate fertilizer composition of the present invention demonstrates a smaller hydrodynamic size relative to the prior art product(s). A reduced hydrodynamic size is indicative of a more uniform and stable dispersion, further contributing to the overall stability and effectiveness of the composition.

[0108] Table 9

[0109] Properties Specification Test Method

[0110] Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses of the invention and obvious modifications and equivalents thereof. Thus, from the foregoing description, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein.

[0111] Accordingly, it is not intended that the scope of the foregoing description be limited to the description set forth above, but rather that such description be construed as encompassing all of the features of patentable novelty that reside in the present invention, including all the features and embodiments that would be treated as equivalents thereof by those skilled in the relevant art. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above but should be determined only by a fair reading of complete specification to follow.

Claims

We claim:

1. A process for preparation of a nano-particulate fertilizer composition, comprising the following steps: a) Jet milling of saccharides and urea; b) Preparing a saccharide solution; c) Addition of organic or inorganic acid to saccharide solution followed by heating at a temperature range 100-120°C and then neutralizing the solution by addition of neutralizing agent to obtain a neutralized solution; d) Preparing a solution of urea; e) Dropwise addition of urea solution to the saccharide solution to obtain a mixture; f) Addition of additives to the mixture obtained in step d) followed by stirring, obtain nanoparticulate fertilizer composition.

2. The process as claimed in claim 1, wherein the ratio of urea to saccharides is 0.5 to 15.

3. The process as claimed in claim 1, wherein the saccharides are selected from at least one monosaccharides or disaccharides or mixture thereof.

4. The process as claimed in claim (s) 1-3, wherein the monosaccharides are selected from the group comprising glucose, dextrose, fructose, and galactose or mixture thereof.

5. The process as claimed in claim (s) 1-3, wherein the disaccharides are selected from the group comprising actose, maltose, and sucrose or mixture thereof.

6. The process as claimed in claim 1, wherein the organic acid is selected from the group comprising acetic acid, ethanoic acid, propionic acid, isobutyric acid, butyric acid, hexanoic acid or mixtures thereof.

7. The process as claimed in claim 1, wherein the inorganic acid is selected from the group comprising Hydrochloric acid, sulfuric acid, phosphoric acid (orthophosphoric acid,), nitric acid, nitrous acid or mixtures thereof.

8. The process as claimed in claim 1, wherein the additives are selected from the group comprising Polyvinyl pyrrolidinone, polyvinyl alcohol, Polyacrylic acid, Polyethylene glycol, N,N-Bis (Phosphonomethyl)glycine, Trisodium citrate, ethylene diamine tetra-acetic acid(EDTA), nitrification inhibitor, urease inhibitor, growth hormone or combinations thereof and are present in the range of 0.5 to 20 % by weight of the composition.

9. The process as claimed in claim 8, wherein the nitrification inhibitor is selected from the group comprising 2-chloro-6-(trichloromethyl) pyridine (nitrapyrin), dicyandiamide (DCD), and 3,4-dimethyl pyrazole phosphate (DMPP) or combinations thereof and is present in the range of 0.5 to 5 % by weight of the total composition.

10. The process as claimed in claim 8, wherein the urease inhibitor is selected from the group comprising N-(n-butyl) thiophosphoric triamide (NBPT) and N-(n-propyl) thiophosphoric triamide (NPPT) or combinations thereof and is present in the range of 0.5 to 5% by weight of the total composition.

11. The process as claimed in claim 8, wherein the growth hormone(s) are selected from the group comprising Auxins, Gibberellins, and Cytokinins and are present in the range of 0.5 to 5 % by weight of the total composition.

12. A nano-particulate fertilizer composition comprising solution of a) urea b) saccharide; c) additives.

13. The nano- particulate fertilizer composition as claimed in claim 12, wherein the additives are selected from the group comprising Polyvinyl pyrrolidinone, polyvinyl alcohol, Polyacrylic acid, Polyethylene glycol, N,N-Bis (Phosphonomethyl)glycine, Trisodium citrate, ethylene diamine tetra-acetic acid, nitrification inhibitor, urease inhibitor , growth hormone or combinations thereof and are present in the range of 0.5 to 20 % by weight of the composition.

14. The nano- particulate fertilizer composition as claimed in claim 13, wherein the nitrification inhibitor is selected from the group comprising 2-chloro-6-(trichloromethyl) pyridine (nitrapyrin), dicyandiamide (DCD), and 3,4-dimethyl pyrazole phosphate (DMPP) or combinations thereof and is present in the range of 0.5 to 5 % w / w by weight of the total composition.

15. The nano- particulate fertilizer as claimed in claim 13 wherein the urease inhibitor is selected from the group comprising N-(n-butyl) thiophosphoric triamide (NBPT) and N-(n-propyl) thiophosphoric triamide (NPPT) or combinations thereof and is present in the range of 0.5 to 5% w / w by weight of the total composition.

16. The nano- particulate fertilizer as claimed in claim 13, wherein the growth hormone(s) is selected from the group comprising Auxins, Gibberellins, and Cytokinins and are present in the range of 0.5 to 5 % by weight of the total composition.

17. The nano- particulate fertilizer composition as claimed in claim (s) 12-16 having particle size ranging from 10 nm to 50 microns.

18. The nano- particulate fertilizer composition as claimed in claim (s) 12-16 having Zeta potential ranges from +120 to -120 mV.

19. The nano- particulate fertilizer composition as claimed in claim 18 having Zeta potential ranges from +40 to -40 mV.

20. The nano- particulate fertilizer composition as claimed in claim (s) 12-16 having nitrogen content in the range of 0.5 to 47%.

21. The nano- particulate fertilizer as claimed in claim (s) 12-16, wherein the ratio of urea to saccharides is 0.5 to 15.

22. A process for preparation of a nano-particulate fertilizer composition, comprising the following steps: a) Jet milling of saccharides and urea; b) Preparing a saccharide solution; c) Addition of organic or inorganic acid to saccharide solution followed by heating at a temperature range 100-120°C and then neutralizing the solution by addition of neutralizing agent to obtain a neutralized solution; d) Addition of additives to the neutralized solution followed by stirring, e) Filtering the solution and distilling out the water for complete dryness f) Preparing a solution of urea; g) Dropwise addition of urea solution to the saccharide solution to obtain a mixture; h) Ultracentrifugation of the obtained mixture to furnish nano-particulate fertilizer composition.

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