DESC:

FORM – 2

THE PATENTS ACT, 1970
(39 OF 1970)

COMPLETE SPECIFICATION
(SECTION 10, RULE 13)

“A PROCESS OF SYNTHESIS OF NANO DAP PLANT NUTRIENT”

RAY NANO SCIENCE AND RESERCH CENTRE LLP
Having address at
Plot no. 7 & 8, GIDC, V UNagar,
Anand, Gujarat, India - 388001

The following specification particularly describes the invention and the manner in which it is to be performed:
FIELD OF INVENTION:
The present invention relates to the utilization of natural as well as synthetic and semi synthetic materials which multifunctionally act as reducing and stabilizing agents for the solubilization of commercially available diammonium phosphate (DAP). The present invention provides a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules using natural and/or synthetic polymers as an encapsulating agent.
BACKGROUND OF INVENTION:
Increased food demands and ceasing nutrient deposits have resulted in a great loss between the food supply and demands over the period of time and this same phenomenon continues further. Due to higher inputs of synthetic fertilizers on lands, greater impacts have been resulted and observed in environment leading to physicochemical conditions of environmental pollution as well as persistent changes in the soil ecology. This impact has greatly decreased the fertility of natural soil thereby hindering the agricultural productivity, human health, and hygiene. Innovations in nano-fortification and nano sizing of minerals-based formulations have the potential to facilitate nutrients bioavailability and efficacy for productivity in multifold increase.
Chemical fertilizers are unsustainable for various reasons inclusive of high application of inefficiency in terms of drying up of plant tissue, massive energy and water inputs for manufacture, and several possible environmental consequences. Food attainment security and sustainability are global critical concerns that necessitate the adapted agricultural practices to effectively counteract the implications of various environmental factors such as climatical changes, exponential population growth, and non-availability of arable land.
Bulk form of fertilizers can be converted into nano scale following top — down (physical) and bottom — up (chemical and biological) approach that greatly enhanced the nutrient uptake in crops resulting in reduction in nutrient dosage and other related anthropogenic problems. As a result, the concept of nano fertilizers (NFs) was developed and applied since the reduced particle size in NFs massively increases the surface area of the constituent particles specifically, thereby increasing the fertilizer's absorption efficiency by leaves of the plant even at much lower fertilizer input.
Primary nutrients are of two forms i.e., macronutrients and micronutrients. Macronutrients primarily includes nitrogen (N), phosphorous (P), and potassium (K) whereas Micronutrients have calcium (Ca), magnesium (Mg) and Sulphur (S). Boron (B), Copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo), and zinc (Zn) as secondary nutrients.
A healthy plant constitutes of three major macronutrients: nitrogen (N), phosphorus (P), and potassium (K). Nitrogen (N) is a necessary component of proteins such as amino acids, and its enzymatic reactions assist in plant growth, especially in stem, leaf, and root; Phosphorus (P) nutrient aids in the development of stronger roots and is essential for energy transfer and cell division; and Potassium (K) component is required for tuber and fruit growth.
Diammonium phosphate (DAP) is one of the most important fertilizers which supplies Nitrogen (N) and Phosphorus (P) as macronutrients for the development of crops. However, excessive utilization of commercial available DAP poses issue with the water bodies as well as in soil which greatly results in poor bio-availability of macronutrients (especially P) for the plants. Further, DAP is time consuming as well as difficult to set or apply the solution formed at the end of the process through sprayer due to production of large particles at the end of the process. Moreover, macronutrient such as phosphorous (P) used in large scale generally contaminates the natural ecosystem especially waterbodies.
Commercially available water-soluble phosphate salts that are readily dissolved in soil solutions and available for plant uptake as high-quality fertilizers such as MAP (monoammonium phosphate), DAP (diammonium phosphate), and TSP (triple superphosphate). However, these soluble phosphates are very mobile in the soil, and a significant portion of them often wind up in surface water bodies through seepage or runoff, leading to eutrophication.
Tri sodium citrate (TSC) has a distant feature of saline, slightly sour flavor and is a mild alkali in nature. TSC functions as both a reducing and coordinating agent. Free electron pairs in carbonyl groups can electro-statically stabilize nanoparticles and act as a coordinating agent in compounds containing metallic atoms with free orbitals.
PRIOR ART AND ITS DISADVANTAGES:
The patent application no. WO2022180504A1 relates to the method of sustained release of macronutrients to a plant locus. The method includes providing a nano-fertilizer composition comprising phosphate nanoparticles, optionally combined with a nitrogen source, where the nano-fertilizer composition is prepared using a mechanochemical force, followed by applying the nano-fertilizer composition to soil. A method for making the nano-fertilizer composition for sustained release of macronutrients is also disclosed. The nano-fertilizer composition prepared by the method of present disclosure demonstrates slow and sustained release of macronutrients, particularly, nitrogen and phosphorus, to the plant locus, with a reduced dose of fertilizer in comparison to commercially used fertilizer compositions in soil conditions.
The major drawbacks of the said prior art is non-usage of natural and/or synthetic polymers as encapsulating agent for nano DAP synthesis. Here, cited prior art provides nano-fertilizer composition comprising phosphate nanoparticles, optionally combined with a nitrogen source, where the nano-fertilizer composition is prepared using a mechanochemical force, followed by applying the nano-fertilizer composition to soil.
The patent application no. WO2021195735A1 relates to an invention which comprises of a method for converting monoammonium phosphate (MAP) and/or diammonium phosphate (DAP) into a non-water-soluble fertilizer, micronized into micron and nano-sized particles, which at the time of application will form a suspension in water for direct application together with the seeds, without being detrimental to germination; the present invention also enables application simultaneously with inoculating microorganisms, as it is likewise not detrimental thereto.
However, the said prior art fails to utilize natural and/or synthetic polymers as encapsulating agent for nano DAP synthesis as compared to the present invention. Herein, said prior art converts monoammonium phosphate (MAP) and/or diammonium phosphate (DAP) into a non-water-soluble fertilizer in micron size. Said prior art also fails to disclose about encapsulation of DAP in water as compared to present invention.
DISADVANTAGES OF THE PRIOR ART:
Most or all of the prior art and non-patent prior arts suffers from all or at least one of the following disadvantages:
• The prior art fails to provide a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules using natural and/or synthetic polymers an encapsulating agent.
• The prior art fails to provide a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules and a method to provide balanced nutrient and protection for plant’s growth.
• The prior art fails to provide a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules and a method to reduce the time and enhance the solubility of DAP in water.
• The prior art fails to provide a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules and a method to reduce the harmful effects of large-scale macronutrient (especially P) fertilizer on the natural ecosystem.
• The prior art fails to provide a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules and a method to provide all macronutrients to plants encapsulated in natural and/or synthetic polymer in its required dosage as mentioned in the standards followed all over the world.
• The prior art fails to provide a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules and a method that has environment- friendly nature.
Thus, there is an unmet need to develop an invention that suffices the purpose of providing a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules and more particularly providing a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules and a method to provide balanced nutrient and protection for plant’s growth.
OBJECTS OF THE INVENTION:
The primary object of the present invention is to provide a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules.
Yet another object of the present invention provides a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules that utilizes naturally reducing and stabilizing agent in the synthesis of nano DAP for providing balanced nutrient and protection for the growth of plants.
Yet another object of the present invention provides a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules that reduces the time duration to enhance the solubility of DAP in water.
Yet another object of the present invention provides a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules that reduces the harmful effect of large-scale P fertilizer on the natural ecosystem especially water bodies.
Yet another object of the present invention provides a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules that provides necessary N and P nutrients to plants encapsulated in natural and / or synthetic polymer in its required dosage and rate as per the standard practices followed world-wide.
Yet another object of the present invention provides a novel manufacturing process of nano structured composite plant nutrients and/or biomolecules that introduces an effective method as environment friendly and plant friendly process.
BRIEF DESCRIPTION OF DRAWING:
Figure 1 : Shows the schematic diagram of the nano-structured DAP process.
Figure 2 : TEM image of nano-structured DAP
Figure 3 Graph showing particle size distribution of nano-structured DAP
Figure 4 Graph showing zeta potential distribution of nano-structured DAP

Meaning of reference numeral of the said component parts of the present invention to provide a novel manufacturing process of the nanostructured processed composite plant nutrients and/or biomolecules:
DAP : Diammonium Phosphate
A1 : Additive 1
A2 : Additive 2
C1 : Cross-linking agent
P : Probe
S : Sonication process
N : Nano formulation

SUMMARY OF THE INVENTION
The present invention relates to a novel manufacturing process of nano structured processed composite plant nutrients and/or biomolecules using natural and/or synthetic polymers as an encapsulating agent. Moreover, the present invention provides a novel process to synthesize the nano DAP for providing balanced nutrient and protection for the growth of plants. The present invention also emphasizes to reduce the dependency on usage of commercially available DAP for growth of the plants. The present invention also provides enhancement of the quality of plant produced using naturally available nutrients and/or fortified nutrients through novel nano-structured formulation. Moreover, the present invention involves a synthesized process with eco-friendly formulation using green chemistry as well as to reduce the dependency of large consumption of the fertilizers.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a novel manufacturing process of nano structured processed composite plant nutrients and/or biomolecules using natural and/or synthetic polymers as an encapsulating agent. Further, present invention utilizes naturally reducing and stabilizing agent in the synthesis of nano DAP for providing balanced nutrient and protection for the growth of plants. Moreover, said present invention provides an effective method of synthesizing nano DAP which is environment friendly and plant friendly process.
Low-molecular-weight carboxylic acids such as citric acid act as natural reducing and stabilizing agents as they easily adsorb to metal oxide-aqueous and metal-aqueous interfaces to function as particle interaction modifiers for the processing of minerals. These agents serve as size controllers, steric stabilizers, and reducing agents in the manufacturing of nanoparticles.
Nitrogen (N) and phosphorous (P) are the two most important macronutrients, which play a plethora of roles in the life cycle of plants in terms of their growth and development. These two elements are involved in important nutrient cycles, enzymatic reactions, and metabolic pathways that influence the bioavailability of these nutrients in the soil. Later on, these elements are supplied to plants in the form of synthetic as well as natural fertilizers. In present invention, N and P falls in the range of 3.0-6.5% and 8.5-17.0% respectively for its required dosage form.
Diammonium phosphate is a type of complex fertilizer which contains 18% nitrogen and 46% phosphorous which is supplied to crops as a basal fertilizer. The average particle size of DAP is in millimeter (mm) which makes it extremely difficult for bioavailability by plants and therefore results in less nutrient efficiency.
Excess amount of phosphorus fertilizers leads to various harmful effects such as eutrophication, algal bloom, etc. To solve this problem, present invention has direct application on leaves through foliar application using spray pumps or drones leading to increased efficiency on nutrient intake and enhanced solubility, causing less phosphorus entry in the waterbodies thereby, impacting greater balanced plant growth with reduced leaching of the nutrient.
The present invention has direct implications for drastically reducing the dosage of nitrogen and phosphorous fertilizers in nanoform as either simple or complex nutrients while increasing the efficiency of the nutrients supplied to plants and utilizing macronutrients such as nitrogen and phosphorus in a ratio of 1:2.5, which is suitable for better crop establishment.
The process of a nano structured processed composite plant nutrients and/or biomolecules using natural and/or synthetic polymers as an encapsulating agent comprises of following steps:
i. collecting and mixing 10-30 grams (w/v) of DAP fertilizer in 50 mL deionized water in beaker,
ii. breaking larger particles of said DAP granules into fine powdery particles form with help of higher energy requiring instruments like ball milling, pulverizer,
iii. filtrating said DAP mixture in Nutsche filter with pore size ranging from 0.2-0.8 µM to obtain pure solution of DAP fertilizer,
iv. preparing concentrated aqueous solution of tri-sodium citrate (Solution A) by dissolving salt concentration of tri-sodium citrate in 5-10 mL water, followed by, agitating and stirring said solution of tri-sodium citrate for particular time intervals with a regular speed interval (in the form of rpm) under standard room temperature conditions for complete dissolution,
v. mixing powdery particles of DAP [as output of step iii] in concentrated aqueous solution of tri-sodium citrate (Solution A) [as output of step iv] for obtaining 55-60 mL combination solution of DAP and trisodium citrate (Solution B) under normal room temperature condition in beaker,
vi. encapsulating natural and/or synthetic polymers as an encapsulating agent along with the presence of cross-linking agent in said solution B obtained from step v followed by stirring and agitating for particular time intervals with a regular speed interval in the form of rpm under standard room temperature conditions to obtain 100 mL resultant colloidal suspension of DAP, trisodium citrate and natural or synthetic polymer (solution C) in beaker,
vii. formulating said nano-DAP formulation through combining resultant colloidal suspension [as output of step vi] and nanoparticles through sonication and homogenization technique carried out by probe sonicator and high-pressure homogenizer at a specific pH level ranging from 6-8.5 and temperature of 35-45°C for 10-25 minutes.
The first step in the present invention is to collect and mix the DAP fertilizer from commercially available manufacturers. Said DAP fertilizer containing 10–30 grams (w/v) were collected and mixed in 50 mL de-ionized water present in beaker.
The second step includes the breaking down of large particles of DAP granules size ranging from 3–5 mm into fine powdery form by using high energy requiring instruments like ball milling, pulverizer, etc. for increasing the surface area.
The third step in the present invention is to filter out said particles of DAP fertilizer into a Nutsche filter having pore size ranging from 0.2–0.8 µM to remove unwanted impurities present with DAP fertilizer.
The fourth step is to prepare a concentrated aqueous solution of trisodium citrate (solution A) by dissolving salt concentration of tri-sodium citrate in 5-10 mL water, followed by agitation and stirring through Laboratory mixer for at least 10, 20, 30, 45, 60, or 120 minutes at 100 to 200, 200 to 300, or 300 to 400 rpm under standard room temperature conditions in the range of 25 to 35 °C until it solubilizes or dissolves completely. The uniform mixing of said solution enhances the stability of final product without leading to agglomeration or precipitation.
With respect to the preparation of a complete soluble aqueous solution for the preparation of nano-structured DAP, various components, including potassium citrate, mono-sodium citrate, and calcium citrate, were used by the present invention in an earlier stage as experimental trials to obtain desirable results; however, these components failed to attain achievable outputs as compared to the cited prior art. Thus, after various experimental trials, tri-sodium citrate solution is utilized by the present invention for obtaining complete dissolution or solubilization to provide nanoparticle stabilization at a specific pH level.
Here, concentrated aqueous solution of trisodium citrate present in the form of 1-3% concentration varies with desired pH value ranging from 3-7 pH of final product and play a significant role as a pH reducing agent. Said solution of trisodium citrate also serves as a stabilizing agent and dispersant in the synthesis of nanoparticles and helps to control the particle size thereby preventing agglomeration and maintaining the colloidal stability during nanoparticle formation. Additionally, said solution acts as a chelating agent and buffering agent for binding of metal ions in solution thereby controlling the nucleation and growth of nanoparticles at a specific pH level.
The fifth step is to mix liquid form of DAP into tri sodium citrate solution slowly under normal room temperature condition ranging between 25 to 35°C to obtain solution having DAP powder blended in tri sodium citrate solution (solution B).
The sixth step is to encapsulate the solution B using natural and synthetic polymers along with crosslinking agent that is later followed by stirring and/or agitation atleast 10, 20, 30, 45, 60, 120 minutes at 100 to 200, 200 to 300 or 300 to 400 rpm under standard room temperature conditions. The resultant colloidal suspension (Solution C) is blended with DAP and encapsulated with natural and synthetic polymers and crosslinking agent with pH ranging between 6-8. Here, cellulosic water-soluble polymers as natural polymers with a range of 0.01-2.5% and polyvinylpyrrolidone as synthetic agent with a range of 0.1–10% are the most preferred choices used for encapsulating agents in said present invention and tripolyphosphate are the most preferred choice for crosslinking agent present in said invention. These polymers are highly versatile water-soluble component and widely used as an encapsulating agent which offers several advantages such as encapsulating active ingredients in controlled release manner thereby, facilitating biocompatibility product. Said polymers provides effective thickening and stabilizing agent while preventing the agglomeration or aggregation of nanoparticles and helps to improve the texture, viscosity, and shelf stability of products in acidic and alkaline conditions.
The final step is to obtain nano-structured DAP formulation through combining resultant colloidal suspension (solution C) [as output of step vi] with nanoparticles through sonication and homogenization technique carried out by probe sonicator and high-pressure homogenizer at a specific pH level ranging from 6-8.5 and temperature of 35-45°C for 10-25 minutes.
In an embodiment of said present invention, a schematic representation of synthesizing novel process of nano-structured DAP is illustrated in the form of Figure 1. Here, as shown in figure 1, Diammonium phosphate (DAP) in presence of water molecule (H2O) forms positive ammonium ions and negative dihydrogen phosphate ions which on further interaction with natural cellulosic polymer as additive 1 (A1), synthetic polyvinylpyrrolidone polymer as additive 2 (A2) and tripolyphosphate as crosslinking agent to form nanoformulation as final structure under interaction of probe and sonication process at temperature ranging between 35-45°C for 10-25 minutes. In addition to that, an image from Transmission electron microscopy (TEM) as show in Figure 2 has been recorded for nano-DAP sample.
Said present invention is a simple one-step process for increasing and enhancing the solubility of DAP fertilizer with reduced time limit through reducing the particle size of DAP to the nanoscale level thereby increasing the surface area. This enhancement is achieved by using capping and reducing agents like water soluble cellulosic polymer and poly vinyl pyrrolidone polymer in tri-sodium citrate solution followed by encapsulation into nano structured polymeric matrix resulting in an environmentally and plant-friendly procedure. Thus, said present invention is considered a non-effluent green technology manufacturing process with no release of harmful by-products into the environment.
WORKING EXAMPLES OF THE INVENTION:
Maize is known as one of the world’s leading crops is widely cultivated as cereal grain in India and most primarily acknowledged as queen of cereals due of its highest genetic yield potential by individuals, thereby, maize crop is considered as third important food crop after rice and wheat in regards to nutrient consumption.
Various field experiments were conducted at Anand Agricultural University, Anand, Gujarat to study the comparative analysis between nano-structured and bulk fertilizer treatment in maize crop for their growth and biochemical attributes. These experiments were laid out in a Randomized Complete Block Design as illustrated in Tables 1-4, with 6 treatments (T1, T2, T3, T4, T5 and T6). Herein, various aspects of the study for their morpho-physiological parameters along with their biochemical attributes were recorded as tabular data with reference to dual spraying of Nano-DAP among treatments over control and fertilizer application either with 50% or 75% were recorded at 30-35 and 50-55 days after sowing for their spray efficiency estimation. The spraying was done with the help of knapsack sprayer having flat fan nozzle with a spray fluid of 500 L/ha.
These treatments were:
T1: Control treatment (no fertilizer treatment)
T2: 100% Recommended Dosage of Nitrogen and Phosphorous (RDNP)
T3: 75% Recommended Dosage of Nitrogen and Phosphorous (RDNP)
T4: 50% Recommended Dosage of Nitrogen and Phosphorous (RDNP)
T5: Addition of 4mL/L Nano DAP (NP1) with T3 treatment as foliar spray
T6: Addition of 4mL/L Nano DAP NP1 with T4 treatment as foliar spray
TABLE 1: Comparative analysis between nanostructured and bulk fertilizer in maize over control treatment and 75% of fertilizer application with respect to their morpho-physiological parameters.
Sr. no. Growth and Yield Parameters Comparison among treatments with respect to spray efficiency of dual spraying of Nano-DAP over control treatment and 75% of fertilizer application
T3 (%) increase over control T5 (%) increase over control T5 (%) increase over respective T3 concentration
1. Plant height at harvest 18.94 62.49 36.61
2. LAI at 60 DAS 28.29 74.63 36.12
3. No. of cobs/plant 10.57 50.41 36.03
4. Cob length (cm) 11.77 50.32 34.50
5. Cob weight (g) 23.33 89.85 53.93
6. Cob yield (kg/ha) 8.52 37.82 27.00
7. Grain yield (kg/ha) 51.38 85.96 22.85
8. Straw yield (kg/ha) 50.09 83.31 22.13
9. Seed index (g) 18.98 42.24 19.55

TABLE 2: Comparative analysis between nanostructured and bulk fertilizer in maize over control treatment and 50% of fertilizer application with respect to their morpho- physiological parameters.
Sr. no. Growth and Yield Parameters Comparison among treatments with respect to spray efficiency of dual spraying of Nano-DAP over control treatment and 50% of fertilizer application
T4 (%) increase over control T6 (%) increase over control T6 (%) increase over respective T4 concentration
1. Plant height at harvest 10.33 32.10 19.73
2. LAI at 60 DAS 17.56 44.88 23.24
3. No. of cobs/plant 8.94 28.46 17.91
4. Cob length (cm) 10.23 28.73 16.79
5. Cob weight (g) 8.28 65.96 53.27
6. Cob yield (kg/ha) 4.68 21.49 16.07
7. Grain yield (kg/ha) 49.23 65.33 10.79
8. Straw yield (kg/ha) 43.11 63.72 14.41
9. Seed index (g) 17.81 28.71 9.26

TABLE 3: Comparative analysis between nanostructured and bulk fertilizer in maize over control treatment and 75% of fertilizer application with respect to their biochemical attributes.
Sr. no. Biochemical attributes Comparison among treatments with respect to spray efficiency of dual spraying of Nano-DAP over control treatment and 75% of fertilizer application
T3 (%) increase over control T5 (%) increase over control T5 (%) increase over respective T3 concentration
1. Chlorophyll a
(mg/gm) 5.66 53.97 45.72
2. Chlorophyll b
(mg/gm) 51.87 566.36 141.23
3. Total Chlorophyll (mg/gm) 12.32 84.58 64.33
4. Total soluble Sugars (%) 2.27 24.09 21.33
5. Phenol (%) 2.56 50.64 46.88
6. Reducing sugars (%) 5.17 60.34 52.46
7. Crude protein (%) 5.25 11.04 5.50
8. Crude fiber (%) 1.32 6.14 4.76
9. Starch (%) 0.66 3.83 3.15
TABLE 4: Comparative analysis between nanostructured and bulk fertilizer in maize over control treatment and 50% of fertilizer application with respect to their biochemical attributes.
Sr. no. Biochemical attributes Comparison among treatments with respect to spray efficiency of dual spraying of Nano-DAP over control treatment and 50% of fertilizer application
T4 (%) increase over control T6 (%) increase over control T6 (%) increase over respective T4 concentration
1. Chlorophyll a
(mg/gm) 4.80 53.97 19.59
2. Chlorophyll b
(mg/gm) 43.46 266.36 19.87
3. Total Chlorophyll (mg/gm) 10.37 84.58 19.65
4. Total soluble Sugars (%) 0.45 24.09 13.12
5. Phenol (%) 15.38 50.64 17.22
6. Reducing sugars (%) 5.17 60.34 13.11
7. Crude protein (%) 1.96 11.04 3.84
8. Crude fiber (%) 2.63 6.14 0.85
9. Starch (%) 0.92 3.83 2.49

For morpho- physiological observation:
As illustrated in tabular format, Tables 1-2 represent comparative analysis table between nanostructured and bulk fertilizer in maize over control treatment and fertilizer application of 75% and 50% with respect to their morpho- physiological parameters showcasing their optimal growth and yield of plants. Here, in each net plot area, five plants were randomly selected for recording the morpho-physiological observations such as plant height at harvesting stage, leaf area index (LAI), number of cobs per plant, cob length, cob weight, cob yield, seed index, grain and straw yield.
For biochemical observation:
As illustrated in tabular format, Tables 3-4 represent comparative analysis table between nanostructured and bulk fertilizer in maize over control treatment and fertilizer application of 75% and 50% with respect to their biochemical attributes including chlorophyll content, total soluble sugars, total phenol, reducing sugars, crude protein, crude fiber and starch content. Here, biochemical attributes are carried out as per the methodology depicted in literature studies as standard analytical reference method.
From the above-mentioned tables (Tables 1-4), said invention facilitated an experimental study on the impact of nano-DAP on nutrient-demanding maize crops, wherein conventional DAP application with a reduced dosage of fertilizer application of 75% and 50% is combined with dual spray application of novel nano-DAP over 100% DAP application, thereby, providing a similar exhibition of optimal growth and development of maize crops. Thus, from overall observation and results, it can be concluded that said invention, having a reduced dosage of nano-DAP foliar spraying treatment, exhibits similar morpho-physiological and biochemical attributes as compared to conventional bulk DAP treatments, leading to no negotiation on the economic potential of crops required for technology acceptance by the farmers.
TABLE 5: Effect of Nano-DAP fertilizer on the total microbial count in soil of maize crops.
Treatments Soil microbial count (cfu/gm)
Location 1 Location 2 Location 3
Initial estimation 5.72
(5.2 x 105) 5.97
(9.4 x 105) -
T1 6.64
(4.4 x 106) 6.95
(8.8 x 106) 6.79
(6.6 x 106)
T2 6.46
(2.9x 106) 6.95
(8.6x 106) 6.69
(5.7 x 106)
T3 6.67
(4.8 x 106) 6.98
(9.5 x 106) 6.82
(7.1 x 106)
T4 6.69
(5.0 x 106) 6.99
(9.9 x 106) 6.84
(7.4 x 106)
T5 6.66
(4.6 x 106) 6.98
(9.5 x 106) 6.82
(7.0 x 106)
T6 6.68
(4.9 x 106) 6.98
(9.5 x 106) 6.83
(7.2 x 106)
cfu = colony forming unit
An embodiment referring to Table 5 shows the microbial population recorded for each treatment (T1–T6), which highlights the effect of nano-DAP application as a foliar spray fertilizer on the total microbial count in the soil of maize crops. Here, a negative impact is observed on the soil microbial population for chemical fertilizer when it is directly applied to the soil surface. These microbial populations include beneficial organisms, which play an important role in the overall plant response to abiotic and biotic stresses. Thus, there is a major worldwide concern about soil degradation due to excessive usage of chemical fertilizers, which hampers the overall production and productivity of crops. To overcome the soil degradation issue, foliar application of nano DAP is directly applied to the plant canopy through foliar spraying, thereby showcasing no negative impact on soil microbes when directly exposed to plants. Thus, the foliar application of nano DAP directly results in the improvement of soil as well as better crop response to fertilizer application and resilience towards abiotic and biotic stresses.
In an embodiment of present invention, figure 3 and figure 4 represents the graphical illustrations on particle size distribution and zeta potential distribution for formulation of nanostructured DAP fertilizer respectively. The measurement of particle size potential value distribution and zeta potential value distribution for nano-DAP dispersion was carried out using Particle Size Analyzer. Here, zeta potential distribution of nano DAP was determined to be -23.6 mV according to the Smoluchowski equation while the nanoparticle size distribution was measured using the dynamic light scattering (DLS) method. Here, the hydro-dynamic diameter of particles was determined to be 73.96 nm using diffusion coefficients of Stoke-Einstein equation. For a poly-dispersed suspension, the obtained mean particle size called ‘z-average’ diameter (dz) is determined by the intensity of the light scattered by the particles and through DLS method, measurements were conducted at 25°C to obtain the z-average particle size ranging from 2 nm to 6 µm with polydispersity index of 0.29.
For zeta potential measurements, electrokinetic potential is specified for a colloidal system, which is a physical property exhibited by any particle in a suspension, and the magnitude of the zeta potential offers the net charge at the diffuse boundary of a particle in a suspension, which ultimately indicates the potential stability of a colloidal system. Hence, if the particles in a suspension have large negative or positive zeta potential values, particles will repel each other with no aggregation of nanoparticles. On the other hand, if particles have small zeta potential values, they will exhibit mutual attraction towards each other and form aggregates of nanoparticles without any external force to keep them apart.
Various safety studies, such as cytotoxicity safety studies, genotoxicity safety studies, and environmental safety studies, were performed in which the formulation of nanostructured DAP liquid fertilizer successfully passed all their safety tests as per the OECD or SOP guidelines at an NABL-certified laboratory. Thus, said formulation of nanostructured DAP liquid fertilizer is safer for the environment with a good significance of non-toxicity level.

ADVANTAGES OF THE INVENTION:
The present invention provides a novel manufacturing process of nano structured processed composite plant nutrients and/or biomolecules.
The present invention provides a process for synthesis of nano structured DAP fertilizers using natural and/or synthetic polymers as an encapsulating agent.
The present invention provides a process for synthesis of nano structured DAP fertilizers to facilitate a balanced nutrient and protection for the growth of plants.
The present invention provides a process for synthesis of nano structured DAP fertilizers to reduce the harmful effect of large-scale P fertilizer on the natural ecosystem especially water bodies.
The present invention provides a process for synthesis of nano structured DAP fertilizers to reduce the time and/or duration kind to enhance the solubility of DAP in water.
The present invention provides a process for synthesis of nano structured DAP fertilizers to provide all the necessary N and P nutrients to plants encapsulated in natural and/or synthetic polymer in its required dosage and rate as per the standard practices followed world-wide.
The present invention provides a process for synthesis of nano structured DAP fertilizers to reduce the dependencies on using commercially available DAP for growth of the plants.
The present invention provides a process for synthesis of nano structured DAP fertilizers to be cost effective process with environmental and plant friendly procedure.
The present invention provides a process for synthesis of nano structured DAP fertilizers to involves synthesis process with eco-friendly formulation process using green chemistry.

,CLAIMS:We claim,

1. A process of synthesis of nano-DAP formulation comprises step of:
i. collecting and mixing 10-30 grams (w/v) of DAP fertilizer in 50 mL deionized water in beaker,
ii. breaking larger particles of said DAP granules ranging from 3-5 mm into fine powdery particles form with help of higher energy requiring instruments like ball milling, pulverizer,
iii. filtrating said DAP mixture in Nutsche filter with pore size ranging from 0.2-0.8 µM to obtain pure solution of DAP fertilizer,
iv. preparing concentrated aqueous solution of tri-sodium citrate (Solution A) by dissolving salt concentration of tri-sodium citrate in 5-10 mL water, followed by, agitating and stirring said solution A for particular time intervals of 10-120 minutes with a regular speed interval of 100-400 rpm under standard room temperature conditions ranging from 25-35°C for complete dissolution,
v. mixing powdery particles of DAP [as output of step iii] in concentrated aqueous solution of tri-sodium citrate (Solution A) [as output of step iv] for obtaining 55-60 mL combination solution of DAP and trisodium citrate (Solution B) under normal room temperature condition in beaker,
vi. encapsulating natural and/or synthetic polymers as an encapsulating agent along with the presence of cross-linking agent in said solution B obtained from step v followed by stirring and agitating for particular time intervals of 10-120 minutes with a regular speed interval 100-400 rpm under standard room temperature conditions with specific pH range for obtaining 70-80 mL resultant colloidal suspension of DAP, trisodium citrate and natural or synthetic polymer (solution C) in beaker,
vii. formulating said nano-DAP formulation through combining resultant colloidal suspension [as output of step vi] and nanoparticles through sonication and homogenization technique carried out by probe sonicator and high-pressure homogenizer at a specific pH level ranging from 6-8.5 and temperature of 35-45°C for 10-25 minutes.
2. The process of synthesis of nano-DAP formulation as claimed in claim 1, wherein said concentrated aqueous solution is tri-sodium citrate solution.
3. The process of synthesis of nano-DAP formulation as claimed in claim 1, wherein said pH range for the colloidal solution of nano-DAP is 6-8.
4. The process of synthesis of nano-DAP formulation as claimed in claim 1, wherein said encapsulating agents are cellulosic water-soluble polymers as natural polymer and polyvinylpyrrolidone as synthetic polymer.
5. The process of synthesis of nano-DAP formulation as claimed in claim 1, wherein said cross-linking agent is tripolyphosphate.
6. The process of synthesis of nano-DAP formulation as claimed in claims 1 and 4, wherein the concentration of said natural polymer lies between 0.01-2.5% and said synthetic polymer lies between 0.1-10%.
7. The process of synthesis of nano-DAP formulation as claimed in claim 1, wherein said nano-DAP formulation comprises of nitrogen in the range of 1-5% and phosphorus in the range of 2.5-12.5%.