Claims:We claim:
1. A multi-nutrient nanoclay polymer composite (MNCPC) comprising:
i. a polymer comprising acrylic acid, acryl amide, a nanoclay; and
ii. one or more nutrient;
wherein the polymer is obtained by polymerising the acrylic acid with the acryl amide and the nanoclay in presence of a crosslinking agent and an initiator;
wherein one or more nutrient is deposited/loaded on the surface of said polymer.
2. The multi-nutrient nanoclay polymer composite, wherein one or more nutrient is a mixture of nitrogen (N) in the range of 9% to 12% (w/w), phosphorus (P) in the range of 2% to 4% (w/w), potassium (K) in the range of 2% to 4% (w/w), zinc (Zn) in the range of 2% to 3% (w/w).
3. The multi-nutrient nanoclay polymer composite, wherein the N, P, K, and Zn nutrients are in the form of one or more of elemental or compound forms and combination(s) thereof.
4. A process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC) as claimed in claim 1, 2, and 3, wherein the process comprises:
a) neutralising acrylic acid (Aa) with neutralising agent at 60% neutralization degree in a distilled water to obtain a neutralised acrylic acid;
b) mixing acrylamide (Am) and nanoclay with the neutralised acrylic acid to obtain a mixture solution;
c) loading nutrient(s) to the mixture solution through nutrient carriers to obtain a reaction solution;
d) adding a crosslinking agent, an initiator to the reaction solution and gradually heating at a temperature in the range of 900C to 1100C for time period in the range of 10 min to 30 min under continues stirring to obtain a polymer composite;
e) washing and drying the polymer composite at temperature in the range of 60oC to 700C under reduced pressure to obtain a multi-nutrient polymer composite.
5. The process as claimed in claim 4, wherein the nanoclay is selected from kaolin, montmorillonite, Attapulgite, mica, bentonite, sercite.
6. The process as claimed in claim 4, wherein weight ratio of nanoclay to monomer is 10% of Acrylic acid and Acryl amide.
7. The process as claimed in claim 4, wherein nutrient carrier is selected from Urea, potassium dihydrogenphosphate, potassium Chloride, Zinc citrate.
8. The process as claimed in claim 1, wherein said crosslinking agent is N, N Methylene bisacrylamide (NNMBA) and the initiator is Ammonium persulfate (APS).
9. The process as claimed in claim 4, wherein the method further comprises passing the MNCPC through sieve to obtain MNCPC of size in the range of 1mm to 4mm.
10. The multi-nutrient nanoclay polymer composite as claimed in claim 1 and 2 is a rhizosphere controlled release formulation (RCF).

, Description:Field of invention
The present invention relates to a multi-nutrient nanoclay polymer composite (MNCPC). Furthermore, it relates to a process for synthesis of said multi-nutrient nanoclay polymer composite.
Background of invention
Indian agriculture, in the post green revolution era is under stress. There are multiple problems viz. emergence of multi-nutrient deficiencies, receding ground water table, declining rate of water availability for agricultural operation and loss of biodiversity. Agricultural productivity is at a stake. Intensive cropping with high yielding varieties along with non-judicious fertilizer application and excessive irrigation, not only caused high cost of production but also pose environmental pollution, for example, NO3 accumulation in ground water, Eutrophication etc.
Optimum N: P2O5: K2O ratio for crop production being 4:2:1. In reality, the ratio in the high productivity areas of Haryana and Punjab being as wide as 33:2:1 to 22:2:1, respectively. Excessive dose of N fertilizers poses serious environmental problem. Apart from mismatch between application of NPK fertilizers, there is very low nutrient use efficiency of nitrogen (40%), phosphorus (15-20%) and potassium (60-70%) caused serious problem both economic and environmental viewpoint.
Nitrogen (N) fertilizer’s use efficiency is low as it is subjected to various losses when applied in soil viz. de-nitrification, leaching and volatilization. Fixation, very low diffusion coefficient and mobility are major problems contributing very low phosphorous (P) use efficiency. Emerging deficiency of potassium (K) is a treat in intensively cultivated cropping systems. Water is going to be scarce natural resource for agricultural use in near future.
Recently, the preparation of polymer/clay superabsorbent composite has attracted great attention because of their relative low production cost, excellent water-retention and their considerable applications in agriculture and horticulture. Because of their excellent characteristics, superabsorbent polymers had been widely used in agriculture and horticulture. The optimized combination of superabsorbent and fertilizers may improve nutrition of plants and mitigate at the same time the environmental impact from water soluble fertilizers, reduce evaporation losses and lower frequency of irrigation.
Hence, there is a need for development of balanced fertilizers formulation containing NPK for major crops such as rice and wheat grown extensively in the Indo Gangetic Plains (IGP).
Singh et al. (‘Studies on novel nanosuperabsorbent composites: swelling behaviour in different environments and effect on water absorption and retention properties of sandy loam soil and soil-less medium,’ Journal of Applied Polymer Science 120, 1448-1458, 2011) while working with Novel Nano-Superabsorbent Composite (NSAPC), reported that 0.75% P-gel amended soil-less medium exhibited most superior moisture release pattern. Moisture release curve (expressed in terms of difference in moisture held at zero pressure and a particular pressure) indicates that soil amended with 0.75% NSAPC led to maximum improvement in its water release.
So, in national level there is just initiation of NCPC based fertilizer formulation or NSAPC as a conditioner for improvement of moisture characteristic of soil-plant system.
In recent years, the study of organic-inorganic nanocomposite has become very important field. Many layered, inorganic mineral micropowders such as mica, attapulgite and kaolinite have been used in the preparation of polymers to achieve lower production cost and higher properties. The swelling clay belonging to 2:1 layered clays are commonly used for the preparation of polymer layered silicate nanocomposites. Montmorillonite, hectorite and saponite are the most commonly used layer silicates in filled-polymer nanocomposite (Park et al., ‘A polyethylene nanocomposite prepared via in-situ polymerization’, Journal of Colloid and Interface Science 251, 160-175, 2002). A number of polymer-layered silicates (PLS) preparation methods have been reported in literature. The three most common methods to synthesize PLS nanocomposite are intercalation of suitable monomer and subsequent in situ polymerization, intercalation of polymer from solution and polymer melt intercalation (Nguyen et al, ‘preparation of polymer clay nanocomposites and their properties. Advances in Polymer Technology’ 25, 270-275, 2006).
Montmorilonite, layered aluminum silicates with highly exchangeable cations and reactive groups on its surface has also been widely used to improve hydrogels properties of polymers (Liu et al., ‘Polymer-layered silicate nanocomposites: in-situ intercalative polymerization of 1- caprolactone in layered silicates’, Journal of Applied Polymer Science, 120, 5725-5731, 2006). Montmorilonite is currently most widely used clay mineral nanofiller because of its cation exchange capacity and the large active surface area when sufficiently delaminated. The layer thickness is nearly 1 nm, while the lateral dimension of layer vary upto several microns or even more, i.e.at least one dimension is in the nanometer range.
A series of poly (acrylic acid-co-acrylamide)/ kaolin composites were prepared to act as release carrier of urea fertilizer by aqueous solution copolymerization of partially neutralized acrylic acid and acrylamide in presence of kaolin nanopowder. The release of urea could be affected by many factors such as contents of crosslinker, kaolin and acrylamide, the neutralization degree of acrylic acid, temperature, pH and ionic strength of release medium (Liang et al., ‘Preparation of Poly (acrylic acid-co-acrylamide)/Kaolin and release kinetics of urea from it’, Journal of Applied Polymer Science 106, 3007-3017).
Zhang et al. (‘Study on superabsorbent composites. XI: Synthesis, characterization and swelling behaviours of polyacrylamide/clay composites based on various clays. Reactive and Functional Polymers 67, 737-745, 2007) reported that equilibrium water absorbency in distilled water for polyacrylamide/clay (PAM/clay) composites incorporated with the same content of clay was in the order PAM/vermiculite > PAM/mica > PAM/attapulgite ˜ PAM/kaolinite > PAM/Na+-montmorillonite and they also proposed that this might be due to the hydration and distension difference of these clays.
All above mentioned problem associated with prior art, there is a need to formulate nanoclay polymer composite (NCPC) based N, P, K fertilizers and evaluating its effect in the agriculture in terms of increasing nutrient and water use efficiency.
Objects of present invention
The main object of present invention is to provide a multi-nutrient nanoclay polymer composite (MNCPC) that can hold plant nutrient and water.
Another object of the invention is to provide process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC).
Another object of present invention is to provide site specific customized fertilizers based on balanced nutrition that can be applied irrespective of soil reaction (acidic, neutral and alkaline).
Another object of present invention is to provide controlled release formulation which can be applied as rhizosphere controlled release formulation (RCF) and fertilizer requirement can be reduced upto 40% through the formulation.
Yet another object of present invention is to stimulate microbial processes in the rhizosphere.
Yet still another object of present invention is to increases the soil’s cation exchange capacity, enhances water holding capacity, acts as a binding agent for the non-clay components, and reduces nutrient loss through leaching.
Summary of present invention
The main aspect of present invention provides a multi-nutrient nanoclay polymer composite (MNCPC), wherein the polymer composite comprises: (a) a polymer comprising acrylic acid, acryl amide, a nanoclay; and (b) one or more nutrient; wherein the polymer is obtained by polymerising the acrylic acid with the acryl amide and the nanoclay in presence of a crosslinking agent and an initiator; wherein one or more nutrient is deposited/loaded on the said surface of polymer; wherein one or more nutrient is a mixture of nitrogen (N) in the range of 9% to 12% (w/w), phosphorus (P) in the range of 2% to 4% (w/w), potassium (K) in the range of 2% to 4% (w/w), zinc (Zn) in the range of 2% to 3% (w/w).
Another aspect of present invention further provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the process comprises: (i) neutralising acrylic acid (Aa) with a neutralising reagent at 60% neutralization degree in a distilled water to obtain a neutralised acrylic acid; (ii) mixing acrylamide (Am) and nanoclay with the neutralised acrylic acid to obtain a mixture solution; (iii) loading nutrient(s) to the mixture solution through nutrient carriers to obtain a reaction solution; (iv) adding a crosslinking agent, an initiator to the reaction solution and gradually heating at a temperature in the range of 900C to 1100C for time period in the range of 10 min to 30 min under continues stirring to obtain a polymer composite; (v) washing and drying the polymer composite to obtain a multi-nutrient polymer composite.
Brief description of figure(s)
The various embodiments of the present disclosure will be better understood when read in conjunction with the following figures.
Figure 1 shows Transmission Electron Microscope (TEM)
Figure 1 (a), (b) and (c) shows Transmission Electron Microscope (TEM) images of MNCPC at different scales. Surface morphology of polymer composites were studied through TEM. Fractured morphology with some specific topography were observed in TEM images of MNCPCs. Exfoliated nature of composites were further confirmed by absence of non-homogenous scattering from clay aggregates.
Figure 1 (d) depicts transmission electron microscopy (TEM) image of nanoclay. Nanosize of clay was confirmed through TEM image which indicated that clay used was at nanoscale dimension (<100 nm).
Figure 2 show FTIR spectra
Figure 2 (a) shows FTIR spectra of Nanoclay
Figure 2 (b) shows FTIR spectra of MNCPC
Figure 2 (c) depicts FTIR spectra of Nanoclay and MNCPC
The strong band occurring around in the range of 3400 to 3800 cm-1 was attributed to the stretching vibration of the Mg–OH, Al–OH or Fe–OH structural hydroxyls groups, typical of montmorillonite. The other vibrational modes characteristic of this clay mineral were the broad band at 1020 cm-1 assigned to Si–O stretching vibrations of the Si–O–Si tetrahedron, the band around 500-700 cm-1 was assigned to the angular deformation of Si–O–Al and the band centered at 470 cm-1 assigned to the angular deformation of Si–O–Si.
The characteristics peak of –OH stretching vibration (3400 cm-1 to 3800 cm-1) as observed in case of original and nanobentonites disappeared in case of MNCPCs irrespective of clay types and clay contents (Fig. 3a and 3b) . Absorption band at 1030 cm-1 (Si-O stretching) disappeared in MNCPCs indicating the interaction of clays (-OH) groups occurs during copolymerization reaction.
Figure 3 shows X-Ray Diffractogram
Figure 3 (a) depicts X-Ray Diffrctogram of Nanoclay
Figure 3 (b) shows X-Ray Diffractogram of MNCPC
Figure 3 (c) shows X-Ray Diffractogram of nanoclay and MNCPC
XRD analysis clearly showed that the typical montmorilllonite peak (2?=6°) became absent in MNCPCs. Absence of typical montmorilonite peak, clearly indicated that bentonite clays completely dispersed into the polymer matrixes which implied that MNCPCs were exfoliated type of composites.
Detailed description of present invention
In the present invention, numbers of terms are used for description of invention. The definitions of terms are as follows:
The term ‘Multi-nutrient nanoclay polymer composite’ or ‘polymer composite’ or ‘MNCPC’ used herein refers to composite materials obtained by polymerisation of acrylic acid, acrylamide and nanoclay, wherein one or more nutrient dispersed into that material.
The terms ‘Multi-nutrient nanoclay polymer composite’, ‘polymer composite’, ‘MNCPC’ can be used interchangeably throughout the specification.
The term ‘one or more nutrient’ used herein refers to an essential element required in plant growth. It includes but not limited to (N), phosphorus (P), potassium (K), zinc (Zn) etc. The N, P, K, and Zn nutrients are in the form of one or more of elemental or compound forms and combination(s) thereof.
The term ‘mixture solution’ used herein refers to a mixture obtained by mixing acrylamide (Am) and nanoclay with the neutralised acrylic acid in a solvent (distilled water).
The term ‘reaction solution’ used herein refers to a solution of neutralised acrylic acid, acrylamide, clay and/or one/more nutrient used for polymerisation process to prepare polymer composite at desired reaction conditions.
One of the embodiment of present invention provides a multi-nutrient nanoclay polymer composite (MNCPC), wherein said polymer composite comprises:
i. a polymer comprising acrylic acid, acryl amide, a nanoclay; and
ii. one or more nutrient(s);
wherein the polymer is obtained by polymerising the acrylic acid with the acryl amide and the nanoclay in presence of a crosslinking agent and an initiator; and
wherein one or more nutrient is deposited/loaded on the surface of said polymer.
Another embodiment of present invention provides a multi-nutrient nanoclay polymer composite, wherein one or more nutrient is a mixture of nitrogen (N) in the range of 9% to 12% (w/w), phosphorus (P) in the range of 2% to 4% (w/w), potassium (K) in the range of 2% to 4% (w/w), zinc (Zn) in the range of 2% to 3% (w/w).
Another embodiment of present invention provides a multi-nutrient nanoclay polymer composite, wherein the N, P, K, and Zn nutrients are in the form of one or more of elemental or compound forms and combination(s) thereof.
Another embodiment of present invention provides a multi-nutrient nanoclay polymer composite (MNCPC), wherein potassium(K) is in the form of at least one compound selected from the group consisting of potash, potassium chloride, carnallite, potassium sulfate, and potassium nitrate.
Another embodiment of present invention provides a multi-nutrient nanoclay polymer composite (MNCPC), wherein phosphorous (p) is in the form of at least one compound selected from the group consisting of CaHPO4, Ca(H2PO4)2, single superphosphate, triple superphosphate, ammonium phosphate, a nitrophosphate and a monorthophosphate.
Another embodiment of present invention provides a multi-nutrient nanoclay polymer composite (MNCPC), wherein nitrogen (N) is in the form of at least one compound selected from the group consisting of ammonia, an ammonium salt, sodium or potassium nitrate, urea, and urea-formaldehyde reaction product.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the process comprises:
a) neutralising acrylic acid (Aa) with neutralising reagent at 60% neutralization degree in a distilled water to obtain a neutralised acrylic acid;
b) mixing acrylamide (Am) and nanoclay with the neutralised acrylic acid to obtain a mixture solution;
c) loading nutrient(s) to the mixture solution through nutrient carriers to obtain a reaction solution;
d) adding a crosslinking agent, an initiator to the reaction solution and gradually heating at a temperature in the range of 900C to 1100C for time period in the range of 10 min to 30 min under continues stirring to obtain a polymer composite; and
e) washing and drying the polymer composite to obtain a multi-nutrient nanoclay polymer composite.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the nanoclay is selected from kaolin, montmorillonite, Attapulgite, mica, bentonite, sercite.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the nanoclay is synthesised by ultracentrifugation technique.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the nutrient carrier is selected from Urea, Potassium dihydrogenphosphate, Potassium Chloride, Zinc citrate.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the neutralising reagent is selected from a group consisting of ammonia, alkali.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the neutralising reagent is ammonia.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the heating is carried out for time period in the range of 5 min to 60 min, more preferably 10 min to 30 min.
In an embodiment, exemplary cross-linking agents may include: glycerides; diepoxides; diglycidyls; cyclohexadiamide; methylene bis-acrylamide; bis-hydroxyalkylamides, such as bis-hydroxypropyl adipamide; formaldehydes, such as urea-formaldehyde and melamine-formaldehyde resins; isocyanates including di- or tri-isocyanates; epoxy resins, typically in the presence of a base catalyst; and derivatives and mixtures thereof.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein crosslinking agent is selected from a group consisting of N, N Methylene bisacrylamide (NNMBA), Mono-, di- and polyesters of acrylic acid, methacrylic acid, itaconic acid, maleic acid, esters of these acids with allyl alcohol or its oxalkylated homologues, polyvalent ones Alcohols, butanediol, hexanediol, polyethylene glycol, trimethylolpropane, Pentaeryltrit, glycerol, polyclycerol, oxyalkylated homologues of these polyhydric alcohols, dihydroxyalkyl monoesters, butanediol diacrylate; Allylacrylamide, triallyl citrate, trimonoallyl, polyethylene glycol ether citrate, N-diallylacrylamide, diallyl phthalate, triallyl citrate, tri-monoallyl polyethylene glycol ether citrate, Allyl ethers of di- and Polyols or their ethoxylates; Polyallyl ethers of glycerine, trimethylolpropane, Pentaerythritol or its oxethylates; Tetraallyloxyethane, polyglycidyl allyl ether, ethylene glycol diglycidyl ether, Glyceringlycidylether; Diamines or their salts with at least two ethylenically unsaturated substituent; Di- or triallylamine, or tetraallylammonium chloride.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite, wherein the crosslinking agent is N, N Methylene bisacrylamide (NNMBA).
In an embodiment, exemplary activators/initiator used in the process may include ceric ammonium nitrate; ammonium persulfate; sodium persulfate; potassium persulfate; ferrous peroxide; ferrous ammonium sulfate-hydrogen peroxide; L-ascorbic acid; and potassium permanganate-ascorbic acid.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the initiator is Ammonium persulfate (APS).
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein drying of MNCPC is carried out in vacuum oven at a temperature in the range of 60oC to 700C under reduced pressure.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the process further comprises passing the MNCPC through sieve to obtain MNCPC of size in the range of 1mm to 4mm.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein multi-nutrient nanoclay polymer composite (MNCPC) is a rhizosphere controlled release formulation (RCF).
In an embodiment, acrylic acid monomer is ethylenically monounsaturated. The said monomer further each comprise a polar functional group that forms a bond to the nanoclay, for example a hydrogen bond, polar bond, ionic bond, coordinate bond or covalent bond.
In an embodiment, acrylic acid is water-soluble, polar, anionic ethylenically monounsaturated monomers. The monounsaturated monomers include monomers containing acidic groups such as carboxylic groups, sulfonic groups, phosphonic groups, and the corresponding salts.
Another embodiment of present invention provides a multi-nutrient nanoclay polymer composite wherein the polymer composite has potential agro-biotechnological applications. It increases in input use efficiency especially fertilizer and water under abiotic stress condition.
In an embodiment, polymer composite provides slow release pattern of nutrients which are potentially helpful to control the deficiency of major nutrient elements in soils like N, P, K, Zn etc. It improves water holding capacities and nutrient release capacity.
Another embodiment of present invention provides a process for synthesis of multi-nutrient nanoclay polymer composite (MNCPC), wherein the nanoclay polymer composite is washed with a solvent selected from water, distilled water, alcohol and mixture thereof.
In an embodiment, MNCPC at 60% RDF increases N, P, K and Zn uptake to the extent of 16.87%, 11.59%, 2.56% and 29.14% respectively as compared to 100% RDF of conventional fertilizers.
Advantages of present invention
• MNCPC is a rhizosphere controlled release formulation (RCF)
• MNCPC can be applied irrespective of soil reaction (acidic, alkaline etc.)
• MNPCPC is site specific customized fertilizer where percentage (%) of N, P, K and Zn can be varied
• MNCPC can reduce Fertilizer requirement upto 40%
• MNCPC at 60% RDF increases N, P, K and Zn uptake to the extent of 16.87%, 11.59%, 2.56% and 29.14% respectively as compared to 100% RDF of conventional fertilizers.
• Polymer composite stimulate microbial processes in the rhizosphere
• Polymer composite is cost effective, wherein benefit: cost ratio is 2:50
The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of present disclosure.
Example:
(A) Synthesis of multi-nutrient nanoclay polymer composite (MNCPC)
46.2g of Acrylic acid (Aa) was neutralized with ammonia (NH3) at 60% neutralization degree in distilled water in a four necked reaction vessel equipped with condenser, thermometer and nitrogen line. Mixture solution was obtained by adding 9.2g of acrylamide (Am) and 5.54 g of Bentonitic nanoclay to the above reaction vessel. 23.28 g of Urea, 8.012gm of KH2PO4, 0.51g of KCl, 6.26 g of Zinc citrate were added as nutrient carriers to attempt maximum percentage of nutrient loading. 0.232 g crosslinking agent, N, N Methylene bisacrylamide (NNMBA) was added. 0.6416g of ammonium persulfate (APS) was added as initiator. The reaction solution was stirred on a magnetic stirrer with hot plate and temperature gradually increased to 900C to 1100C under continuous stirring. Synthesized polymer composites was washed with distilled water and collected in petri-plates. MNCPC was dried in vacuum oven at temperature in the range of 600C to 700C under reduced pressure. The dried polymer composite was sieved to obtain uniform particle size in the range of 1mm to 4mm. The MNCPC was synthesised by using various parameters as tabulated in table 1.
Table 1: Synthesis of MNCPC
monomer (g) monomer (g) Crosslinking agent
(g) Initiator
(g) Reaction temperature
(0C) Time period
(min) Product (MNCPC)
Acrylic acid Acrylamide N, N Methylene bisacrylamide (NNMBA) Ammonium persulfate (APS) 90 30 MNCPC 1
Acrylic acid Acrylamide N, N Methylene bisacrylamide (NNMBA) Ammonium persulfate (APS) 95 25 MNCPC 2
Acrylic acid Acrylamide N, N Methylene bisacrylamide (NNMBA) Ammonium persulfate (APS) 100 20 MNCPC 3
Acrylic acid Acrylamide N, N Methylene bisacrylamide (NNMBA) Ammonium persulfate (APS) 105 15 MNCPC 4
Acrylic acid Acrylamide N, N Methylene bisacrylamide (NNMBA) Ammonium persulfate (APS) 110 10 MNCPC 5

(B) Characterisation of MNCPC synthesised
The Product, MNCPC, was characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM) and FTIR (Fourier Transform Infrared) spectroscopy. KBr pellet method was used for preparation of samples in FTIR studies. Gold-palladium coating under vacuum was used for SEM analysis. Total nutrient content at MNCPC were determined by using tri-acid digestion method (HNO3: HClO4:H2SO4 (10:4:1) and Zn content was determined by Atomic Absorption Spectrophotometry (AAS). Nutrient release and physical properties of MNCPC synthesised in Example 1 (a) were showed in table 2.
Table 2: Nutrient release and physical properties of MNCPC
MNCPC Nutrient Release in soil at 60 days after incubation Equilibrium water absorbency (WA) ( g g-1) Maximum water holding capacity (%)
Nitrogen
release
(%) Phosphorous release
(%)
Potassium release
(%) Zinc
release (%)
MNCPC 1 77.89 76.22 80.12 52.45 29.84 2005
MNCPC 2 79.12 77.23 80.50 53.24 29.81 2008
MNCPC 3 79.85 78.23 80.72 53.55 29.95 2010
MNCPC 4 79.85 78.50 80.73 53.98 30.12 2015
MNCPC 5 78.12 77.90 79.23 53.10 29.82 2011

Available N, P, K and Zn content in Alluvial soil after 60 days of incubation is given in Table 3
Table 3 Available N, P, K and Zn content in soil after 60 days of incubation under application of MNCPC
MNCPC Types KMNO4-N
(kg ha-1) Olsen P
(kg ha-1) NH4OAC K
(kg ha-1) DTPA Zn (mg kg-1)
MNCPC 1 335.53 25.02 230.69 2.93
MNCPC 2 337.74 26.02 231.12 2.97
MNCPC 3 336.23 27.23 232.45 2.98
MNCPC 4 332.32 25.02 230.45 2.96
MNCPC 5 334.23 24.23 229.15 2.95