WO2017115314A1

WO2017115314A1 - An innovative method employing geo-specific polybioinoculants for sustainable agriculture

Info

Publication number: WO2017115314A1
Application number: PCT/IB2016/058068
Authority: WO
Inventors: Pavan Kumar DR.PINDI
Original assignee: Dr Pindi Pavan Kumar
Priority date: 2015-12-31
Filing date: 2016-12-29
Publication date: 2017-07-06

Abstract

Exemplary embodiments of the present disclosure are directed towards a method that employs polybioinoculant compositions in a geo-specific and crop specific manner. The present invention also discloses polybioinoculant compositions comprising Plant Growth Promoting Rhizobacteria (PGPR) that act as biofertilizers. The present invention disclosure is based on an innovative selection method for the isolation of PGPR and infers that the efficient and/or novel microbial isolates can be used for promoting sustainable agriculture. Possible combinations of these geo- plant specific isolates will make a novel potential bioformulation namely, Geo Specific Efficient and/or novel Cultivable-Plant Growth Promoting Rhizobacteria (GSEC-PGPR). This novel approach can be employed in any area of same geographical conditions and can be used in the reclamation of problematic sites like agricultural areas, barren lands, drought prone areas, polluted soils, coal mines, barren lands etc. as a step forward for Evergreen Revolution.

Description

AN INNOVATIVE METHOD EMPLOYING GEO-SPECIFIC POLYBIOINOCULANTS FOR SUSTAINABLE AGRICULTURE

TECHNICAL FIELD

[0001] The present invention generally relates to the field of bio-fertilizers. More particularly, the present invention relates to a method for enhancing soil fertility and crop growth, wherein the method employs polybioinoculant compositions in a geo-specific and crop specific manner. The present invention also discloses polybioinoculant compositions comprising Plant Growth Promoting Rhizobacteria (PGPR) that act as biofertilizers.

BACKGROUND

[0002] In the present agricultural scenario, the condition and health of soil health is of major concern as it is highly responsible for sustainable crop production by virtue of a huge number of eco-friendly microorganisms. Over exploitation of synthetic fertilizers has become the regular practice with an aim to optimize the yield which has been consequently destroying the soil biota. Many studies reveal that selecting efficient organisms, culturing and inoculating of organisms directly into soils or through seeds enhanced the microbial utility. Bioinoculants are agricultural amendments that employ favorable endophytes (microbes) to promote plant health. Many of the microbes are the ones involved form symbiotic relationships with the target crops, where the phenomenon of mutualism is applicable. Bioinoculants could be classified as bacterial, fungal and composite. Bacterial bioinoculants include rhizobacterial inoculants, where the rhizobacteria are commonly applied as inoculants and include nitrogen-fixers and phosphate-solubilisers, which enhance the availability of the macronutrients, nitrogen and phosphorus to the host plant and usually contribute for the plant growth and increase the crop yield and such bacteria are commonly referred to as plant growth promoting rhizobacteria (PGPR). PGPR and other root-colonizing bacteria may promote plant growth directly or indirectly or synergistically. The other examples include nitrogen fixing bacteria and phosphate solublising bacteria (PSB). Bacterial inoculation has a much better stimulatory effect on plant growth in nutrient deficient soil than in nutrient rich soil. The best known examples of PGPR are Azospirillum, Rhizobium, Bacillus, Azotobacter and Pseudomonas.

[0003] There are reports on formulating bioinoculants from different geographical conditions and using them at entirely different conditions and crops which resulted in losing the host-specificity and viability of the bioinoculants. The traditional way of preparing biofertilizers involves the direct isolation of PGPR from the soil without prioritizing the specificity of the plant with respect to soil type. Such investigations require huge economic investments and usually are time consuming.

[0004] In the light of aforementioned discussion, there exists a need for a solution to overcome the problems associated with traditional way of preparing biofertilizers and imparting more benefits to the present scenario and practices employed in the field of agriculture. The present invention discloses a strategic novel approach of formatting and developing geo-specific and crop-specific bio fertilizers (efficient and/or novel poly bio inoculants), which can be used in any area of the same geographical conditions. The present invention disclosure is based on an innovative selection method for the isolation of bioinoculants such as PGPR that can be efficiently utilized as biofertilizers. The present invention discloses a method for enhancing soil fertility and crop growth and also discloses polybioinoculant compositions comprising PGPR. The method employs polybioinoculant compositions in a geo-specific and crop specific manner. The Geo-Specific Efficient and/or novel Cultivable-Plant Growth Promoting Rhizobacteria (GSEC-PGPR) will be used as potential polybioinoculants for sustainable agriculture and further, their mass production is carried out. This novel approach is used in the reclamation of problematic sites like agricultural areas, barren lands, drought prone areas, polluted areas, coalmines, etc.

BRIEF SUMMARY

[0005] The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the invention or delineate the scope of the invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later. [0006] Exemplary embodiments of the present disclosure are directed towards a method for enhancing soil fertility and crop growth. The method starts with a first step of collecting rich soil samples from a particular geographical area, wherein the rich soil sample has a rich microbial diversity. The particular geographical area from where the rich soil samples are collected has the same climatic conditions as that of a geographical area of a test soil, wherein the test soil has poor nutrition and poor microbial diversity when compared with the rich soil sample. The next step is to grow crop seedlings in a pot having at least one layer of the rich soil sample and at least one layer of the test soil to enable a plurality of a microorganisms present in the rich soil sample to get associated with a root portion of the crop seedling. The next step is to isolate the microorganisms from the root portion followed by screening the microorganisms to select a group of microorganisms, wherein the group of microorganisms enhance the growth of the crop seedling. This is followed by identification of the group of microorganisms and culturing the group of microorganisms to get a polybioinoculant composition, wherein the polybioinoculant composition acts as a bio-fertiliser. The last step is to apply the polybioinoculant composition to the test soil for enhancing fertility of the test soil and for reclamation of the test soil.

[0007] Yet another exemplary embodiment of the present disclosure is directed towards a polybioinoculant composition that acts as a bio-fertilizer comprising a group of microorganisms obtained from a rich soil sample. The rich soil sample is collected from a particular geographical area and has a rich microbial diversity. The particular geographical area has the same climatic conditions as that of a geographical area of a test soil, wherein the test soil has poor nutrition and poor microbial diversity when compared with the rich soil sample. The polybioinoculant composition is applied in a geo-specific and crop specific manner to the test soil for enhancing fertility of the test soil and for reclamation of the test soil.

[0008] It is an object of the present invention to disclose a premeditated and novel approach of configuring and developing geo-specific and crop-specific bio fertilizers such as efficient and/or novel poly bio inoculants. The polybioinoculants can be employed in any area of the same geographical conditions. So the organisms of one area of this region are well adaptable to the conditions of other area of the same region, which is the basic principle of the study. This approach will exploit the possible optimization of efficient microbes as biofertilizers. Prevalence of climatic similarity in the same geographical region is the central dogma of this research work. The organisms can effectively survive in the same geographical conditions without any reduction in their numbers and efficiencies thus reducing the total input costs and improving soil health that consequently elevates the wellbeing of the rural poor in these areas. Furthermore, the present invention discloses an approach directing isolation, screening, and identification and culturing of the microbes in the soils that have been extensively supporting the plant growth. Biochemical assay(s) of the inoculants are made for the confirmation of production of Siderophore, Ammonia, HCN, IAA and GA and phosphate solubilization. Apart from the biochemical assay, molecular characterization is carried out for the potential isolates using 16S rDNA sequencing.

BRIEF DESCRIPTION OF DRAWINGS

[0009] Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, in conjunction with the accompanying drawings, wherein like reference numerals have been used to designate like elements, and wherein:

[0010] FIG. 1 is a diagrammatic representation of a method for enhancing soil fertility and crop growth by employing geo-specific and crop specific polybioinoculant compositions in accordance with a non limiting exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

[0011] It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. [0012] The use of "including", "comprising" or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. Further, the use of terms "first", "second", and "third", and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

[0013] According to a non limiting exemplary embodiment of the present disclosure, a method for enhancing soil fertility and crop growth by employing geo- specific and crop specific polybioinoculant compositions is disclosed.

[0014] In accordance with a non limiting exemplary embodiment of the present disclosure, polybioinoculant compositions that act as biofertilizers are disclosed.

[0015] According to a non-limiting exemplary embodiment of the present disclosure, a method for enhancing soil fertility and crop growth by employing geo- specific and crop specific polybioinoculant compositions is disclosed. The method starts with a first step of collecting rich soil samples from a particular geographical area, wherein the rich soil sample has a rich microbial diversity. The particular geographical area from where the rich soil samples are collected has the same climatic conditions as that of a geographical area of a test soil, wherein the test soil has poor nutrition and poor microbial diversity when compared with the rich soil sample. The next step is to grow crop seedlings in a pot having at least one layer of the rich soil sample and at least one layer of the test soil to enable a plurality of a microorganisms present in the rich soil sample to get associated with a root portion of the crop seedling. The next step is to isolate the microorganisms from the root portion followed by screening the microorganisms to select a group of microorganisms, wherein the group of microorganisms enhance the growth of the crop seedling. This is followed by identification of the group of microorganisms and culturing the group of microorganisms to get a polybioinoculant composition, wherein the polybioinoculant composition acts as a bio-fertiliser. The last step is to apply the polybioinoculant composition to the test soil for enhancing fertility of the test soil and for reclamation of the test soil. [0016] In accordance with a non limiting exemplary embodiment of the present disclosure, polybioinoculant compositions that act as a bio-fertilisers are disclosed. The polybioinoculant compositions comprise of a group of microorganisms obtained from a rich soil sample. The rich soil sample is collected from a particular geographical area and has a rich microbial diversity. The particular geographical area has the same climatic conditions as that of a geographical area of a test soil, wherein the test soil has poor nutrition and poor microbial diversity when compared with the rich soil sample. The polybioinoculant composition is applied in a geo-specific and crop specific manner to the test soil for enhancing fertility of the test soil and for reclamation of the test soil.

[0017] In accordance with a non limiting exemplary embodiment of the present disclosure, the rich soil sample is from a forest area and wherein the rich soil sample is a rhizospheric soil. In a particular embodiment, the geographical area of the rich soil sample is adjoining the geographical area of the test soil.

[0018] According to a non limiting exemplary embodiment of the present disclosure, the polybioinoculant composition comprises of a Plant Growth Promoting Rhizobacteria (PGPR). In different embodiments, the Plant Growth Promoting Rhizobacteria comprise of one or more of a Azospirillum, Rhizobium, Bacillus, Azotobacter, Phosphate solubilizing bacteria and Pseudomonas.

[0019] Referring to FIG. 1, it is a diagrammatic representation of a method for enhancing soil fertility and crop growth by employing geo-specific and crop specific polybioinoculant compositions in accordance with a non limiting exemplary embodiment of the present disclosure. The method comprises of the following steps: a) Selecting a forest soil which is undisturbed as a rich source of an efficient and/or novel plant growth promoting rhizobacteria (PGPR). b) Placing of the forest soil as a single layer of 2-3 cm sandwiched in between two layers of test soil samples along with a control of problematic areas in pots; c) Sowing the pots with the seeds of the same batch; d) Screening of the best supporting and undisturbed forest soil for the presence of the plant growth promoting rhizobacteria; e) Identifying an efficient and/or novel strain of the plant growth promoting rhizobacteria. f) Characterizing the plant growth promoting rhizobacteria by polyphasic taxonomy; g) Carrying out mass production of geo-specific, efficient and/or novel, cultivable, plant growth promoting rhizobacteria; h) Employing the geo-specific, efficient and/or novel, cultivable, plant growth promoting rhizobacteria (GSEC-PGPR) as the poly bio inoculants for the sustainable agriculture; and i) Employing the plant growth promoting rhizobacteria is in the reclamation of problematic sites like poor agricultural areas, drought prone areas, barren lands, polluted soils, coalmines, etc.

[0020] According to a non limiting exemplary embodiment of the present disclosure, a number of undisturbed forest soils of same geographical area are used each as one layer in the same test soil (poor agriculture soil) in series of pots and sowed with same batch/crop/plant seeds. The main criterion for the selection of same geographical location is similar growth conditions, the viability of the spores, similar soil microbiota and negligible variation in soil composition. The undisturbed forest soil which is placed as a single layer will be rich source of efficient and/or novel plant growth promoting rhizobacteria (PGPR) and enhances the plant growth tremendously based on availability of the presence and host specificity of PGPR.

[0021] Further referring to Fig. 1, three different rich soil samples from the forest (FS 1, FS2 and FS3) were layered in between a top layer and a bottom layer of the test soil samples and the seeds are sown in the layer having rich soil samples. As can be seen, the seedlings emerging from the rich soil samples show enhanced growth when compared with the control. This was followed by individual screening of the strains. As seen in Fig. 1, colonies numbered 7, 9 and 2 from Rhizobium, PSB and Azotobacter strains respectively were found to be best bioinoculants. These were employed in the field and found to be best supporter of plant growth. [0022] In accordance with a non limiting exemplary embodiment of the present disclosure, at different time intervals, plant growth parameters were recorded and best supporting forest soil sample was screened for an individual pure culture of PGPR. Among each individual PGPR which is at least one of Rhizobium, Azotobacter, Phosphate solubilizing bacteria, etc, efficient strains were identified and characterized by polyphasic taxonomy. All efficient PGPR bacteria were mixed and used as polybioinoculants which are geo-specific, plant /crop specific and can used in any area of same geographical conditions. Also, they have long viability, efficiency due to adaptation of same environmental factors and climatic conditions.

[0023] According to a non limiting exemplary embodiment of the present disclosure, the developed efficient and/or novel polybioinoculants are used in the reclamation of problematic sites like poor agricultural areas, drought prone areas, barren lands, polluted soils, coalmines, etc.

[0024] In accordance with a non limiting exemplary embodiment of the present disclosure, the poly bioinoculant is employed for the growth of Gossypium hirsutum. Tremendous enhancement in the plant growth was observed in the presence of polybioinoculant.

EXAMPLES:

Nature of soil - Undisturbed Rhizosphere soils

[0025] According to a non limiting exemplary embodiment of the present disclosure, the soils that do not have any previous exposure to chemical application were selected as undisturbed rhizosphere soils. Hence, there was no chance for the microbial inhibition by the chemical effect of synthetic fertilizers. Plants in these areas were found to be healthy and green; it might be due to the presence of rhizosphere.

Soil Analysis

[0026] In accordance with a non limiting exemplary embodiment of the present disclosure, the physico chemical analysis of soil was performed. The nitrogen level was estimated by the alkaline potassium permanganate method for estimation of available phosphorous. Flame photometric method was employed for potassium determination.

Soil collection and bacterial isolation [0027] According to a non limiting exemplary embodiment of the present disclosure, the collected soils were brought to the laboratory and kept in separate pots (Triplicates). The same geographic rhizosphere soils were collected from forests located in the area under investigation. These forest rhizosphere soils were placed as a single layer of 2-3 cm in between the test samples of problematic areas in pots and then those pots were sown with the seeds of the same plant/family of the then collected rhizosphere soil of the forest(s). The pots were sown with the seeds of desired crop accordingly. Rhizobium, Azospirillum, and Bacillus Sp. were isolated on individual culture media by the serial dilution method. For the isolation of Rhizobium Pikovaskaya' s medium, for Azospirillum Titan media and Soya bean tripticase agar for Bacillus was used. Pseudomonas and Azotobacter were isolated on PC (Phenonthroline Columbia) and Jensons media, respectively.

Effect of poly bioinoculants on the growth of cotton plants Gossypium hirsutum L

[0028] According to a non limiting exemplary embodiment of the present disclosure, twelve different locations of Kothagudem forest of Khammam district were selected. The geographical conditions of these locations are closely similar to that of Mahabubnagar (temperature, pH, moisture). Soil samples from four different cotton fields at Jadcherla, Kalwakurthy, Makthal and Achempet were collected to assess the efficiency/novelty of isolates. Also, soil samples from problematic sites such as coal dumped area, polluted soils, and barren lands were collected from Balnagar, Kothur and Maddur for checking the potentiality of isolates in reclaiming the vegetation of problematic soils. Soils from 12 locations of Kothagudem forest were brought to the laboratory and kept in separate pots (Triplicates). The same geographic rhizosphere soils were collected from forests located in the area under investigation. These forest rhizosphere soils were placed as a single layer of 2-3 cm in between the test samples of problematic areas in pots and then those pots were sown with the seeds of the same plant/family of the then collected rhizosphere soil of the forest(s). The pots were sown with the seeds of Gossypium hirsutum (Industrial crop) accordingly. Rhizobium, Azospirillum, and Bacillus Sp. were isolated on individual culture media by the serial dilution method. For the isolation of Rhizobium Pikovaskaya' s medium, for Azospirillum Titan media and Soya bean tripticase agar for Bacillus was used. Pseudomonas and Azotobacter were isolated on PC (Phenonthroline Columbia) and Jensons media respectively. Successful utilization of the sample for the screening yielded potential PGPR and on individual screening of each genus of different PGPR, Azospirillum Sp. PPK-27, Bacillus Sp. PU-6, Rhizobium Sp. RHPU-7 and dominant mycorrhizal spore of Gigaspora roses were obtained which were applied in pure culture on the cotton crops grown in vegetatively poor soils of Mahabubnagar district. A tremendous enhancement in plant growth was observed, thus inferring that this method of geographically based selection of bioinoculants (Bio-Geo inoculants) in relation to the specific crop variety may be employed for the reclamation of vegetation in the soils that support agriculture inadequately.

Preparation of standard inoculums

[0029] In accordance with a non limiting exemplary embodiment of the present disclosure, standard inoculum was prepared by inoculating log phase cultures of all the species of Rhizobium, Azospirillum, Bacillus, Pseudomonas and Azotobacter in nutrient broth. One ml of each sample was added over the seeds of desired crop at the time of sowing in sterilized soil for a period of 90 days.

Genomic DNA Extraction

[0030] In accordance with a non limiting exemplary embodiment of the present disclosure, a modified method of Sambrock et al. (Mullis, 1990) was adopted for the genomic DNA isolation. The samples were centrifuged (12,000rpm) for 2 min, the pellets were mixed with 600 μΐ lysis buffer (10mm tris -HC1, lmM EDTA [pH 75], 0.5% SDS 3100/g/ml proteinase c followed by incubation at 37°c for lhr after adding 100 μΐ 5 M NaCl, and 80μ1 CTAB NaCl. The samples were subjected to incubation at 65 °C for 10 mins and cooled to room temperature followed by the extraction of aqueous phase with the equal volume of chloroform: isoamylalcohol [24: 11, v/v] and equal volume of phenol : chloroform: isoamylalcohol (25:24: 1, v/v_ which was centrifuged at 12, 000 rpm & 4°Cfor 10 min. Isopropanol (0. 6x) was mixed with the aqueous phase, and centrifuged at 12, 000 rpm and at 4°C for 10 min. The DNA pellets were dried under vacuum, and then dissolved in TS Buffer (lOmM Tris-HCl, and IMm EDTA [pH. 75]).

PCR Analysis

[0031] According to a non limiting exemplary embodiment of the present disclosure, in polymerase chain reaction, 16S rRNA universal primers were used to amplify the small subunit rRNA of each sample's culture DNA. The reaction mixture of 50 μΐ contains 4μ1 bacterial DNA (nearly 200ng), Ιμΐ Taq-DNA polymerase, 5μ1 of Taq buffer, 5μ1 of 2mM dNTP mix, 5 μΐ of forward primer (10 ρΜ/μΙ) and 5 μΐ of reverse primer (10 ρΜ/μΙ). PCR amplification was carried out in a Bio-Rad thermo cycler run for 30 cycles. Denaturation was done for 94°C for 20s, annealing at 48°C for 20s and extension was done at 72°C for 40s for each cycle, final extension was carried out for 5min at 72°C at the end of all 30 cycles. The amplified PCR product of approximately 1542 bp was separated on a 1% agarose gel and purified by Qiagen spin columns.

16S rRNA gene sequencing

[0032] In accordance with a non limiting exemplary embodiment of the present disclosure, the purified 1542bp PCR product was sequenced using universal primers. The complete 16S rRNA gene sequence of the isolate was subjected to BLAST sequence similarity search and Ez Taxon to identify the nearest taxa. The entire related 16S rRNA gene sequence was downloaded from the database (http://www. nbi .nlm.nih-gov) aligned using the celestial - program.

Biochemical characterization

[0033] According to a non limiting exemplary embodiment of the present disclosure, biochemical assay(s) of the inoculants were carried out for the confirmation of production of Siderophore, Ammonia, HCN, IAA and GA and phosphate solubilization. For the estimation of phytohormone, the crushed product of lgm of leaf sample was mixed with 1ml of phosphate buffer and centrifuged. The supernatant was added with 2 drops of perchloric acid to make the volume to 2 ml with 52% 0.5 M FeC13 in 35% perchloricacid acid i.e. Salkowaski reagent. The OD values were taken at 530 nm by UV- Visible spectrophotometer after 25min. Plotting the concentrations of IAA in micrograms /ml Vs Optical Density at 530 nm a standard graph was prepared. The estimation of total protein content, proline, total soluble sugar and chlorophyll pigment was done according to standard procedures.

Statistical Analysis

[0034] In accordance with a non limiting exemplary embodiment of the present disclosure, statistical software SPSS for Windows version 17.0. ANOVA was used for Statistical analysis; t- test was applied on subjects to know the significance of mean difference and multiple mean differences respectively. P- values were considered as significant at the 5 % level (or 95% 14confidence level).

[0035] Although the present disclosure has been described in terms of certain preferred embodiments and illustrations thereof, other embodiments and modifications to preferred embodiments may be possible that are within the principles and spirit of the invention. The above descriptions and figures are therefore to be regarded as illustrative and not restrictive.

[0036] Thus the scope of the present disclosure is defined by the appended claims and includes both combinations and sub combinations of the various features described herein above as well as variations and modifications thereof, which would occur to persons skilled in the art upon reading the foregoing description

Claims

1. A method for enhancing soil fertility and crop growth comprising: a) Collecting a plurality of a rich soil sample from a particular geographical area, wherein the rich soil sample has a rich microbial diversity and wherein the particular geographical area has the same climatic conditions as that of a geographical area of a test soil, wherein the test soil has poor nutrition and poor microbial diversity when compared with the rich soil sample; b) Growing a plurality of a crop seedling in a pot having at least one layer of the rich soil sample and at least one layer of the test soil to enable a plurality of a microorganisms present in the rich soil sample to get associated with a root portion of the crop seedling; c) Isolating the microorganisms from the root portion followed by screening the microorganisms to select a group of microorganisms, wherein the group of microorganisms enhance the growth of the crop seedling; d) Identification of the group of microorganisms followed by culturing the group of microorganisms to get a polybioinoculant composition, wherein the polybioinoculant composition acts as a bio-fertilizer; and e) Applying the polybioinoculant composition to the test soil for enhancing fertility of the test soil and for reclamation of the test soil.

2. The method as claimed in claim 1 , wherein the rich soil sample is from a forest area and wherein the rich soil sample is a rhizospheric soil.

3. The method as claimed in claim 1, wherein the particular geographical area of the rich soil sample is adjoining the geographical area of the test soil.

4. The method as claimed in claim 1, wherein the polybioinoculant composition is geo- specific and crop specific.

5. The method as claimed in claim 1, wherein the polybioincoculant composition comprises of a Plant Growth Promoting Rhizobacteria.

6. The method as claimed in claim 5, wherein the Plant Growth Promoting Rhizobacteria comprises of at least one of a Azospirillum, Rhizobium, Bacillus, Azotobacter, Phosphate solubilizing bacteria and Pseudomonas.

7. A polybioinoculant composition that acts as a bio-fertilizer comprising a group of microorganisms obtained from a rich soil sample collected from a particular geographical area, wherein the rich soil sample has a rich microbial diversity, wherein the particular geographical area has the same climatic conditions as that of a geographical area of a test soil, wherein the test soil has poor nutrition and poor microbial diversity when compared with the rich soil sample and wherein the polybioinoculant composition is applied in a geo-specific and crop specific manner to the test soil for enhancing fertility of the test soil and for reclamation of the test soil.

8. The polybioinoculant composition as claimed in claim 7, wherein the rich soil sample is from a forest area, wherein the rich soil sample is a rhizospheric soil and wherein the particular geographical area of the rich soil sample is adjoining the geographical area of the test soil.

9. The polybioinoculant composition as claimed in claim 7, wherein the polybioincoculant composition comprises of a plant growth promoting rhizobacteria.

10. The polybioinoculant composition as claimed in claim 9, wherein the plant growth promoting rhizobacteria comprises of at least one of a Azospirillum, Rhizobium, Bacillus, Azotobacter, Phosphate solubilizing bacteria and Pseudomonas.