WO2018215925A1

WO2018215925A1 - A biological soil conditioner

Info

Publication number: WO2018215925A1
Application number: PCT/IB2018/053603
Authority: WO
Inventors: Rajesh Aggarwal; L.C. Rohela; R.K. Jain; Ajay BHOKTA
Original assignee: Insecticides (India) Limited
Priority date: 2017-05-22
Filing date: 2018-05-22
Publication date: 2018-11-29

Abstract

The present invention discloses fungal strains and their consortium that can effectively improve the soil properties. The present invention also relates to a soil improving composition comprising at least one of best isolated fungal species. The isolated strains and the compositions of the present invention can be used in various agro-based products which are useful for soil and crop productivity. The present invention also provides a method of manufacturing said composition, and also the method of using said strain(s)/composition for agriculture purposes.

Description

A BIOLOGICAL SOIL CONDITIONER

FIELD OF THE INVENTION

The present invention relates to isolated fungus which can effectively improve the soil and crop properties/productivity. The present invention also relates to a soil improving synergistic composition comprising at least one of said isolated fungal species. The isolated strains and the compositions of the present invention can be used in various agro-based products. The present invention also provides a method of manufacturing said composition, and also the method of using said strain(s)/composition for agriculture purposes. BACKGROUND OF THE INVENTION

This section includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the present invention, or that any publication specifically or implicitly referenced is prior art.

Plant growth and crop productivity is dependent mainly on the soil physical, chemical and biochemical conditions. Characteristics of the good soil are high water intake capacity and movement, plant growth development and aeration of the soil. The improvement in soil properties such as physical, chemical and biochemical properties often termed as soil conditioning and a substance that can be added to soil to bring out such changes in soil properties often termed as soil conditioner. Although green revolution has increased agricultural productivity for a while, this has again stagnated afterwards due to the use of extensive chemical fertilizer deteriorating the soil health leading towards low productivity of agriculture produce. To improve agricultural productivity, most of the farmers use chemicals to fertilize plants, fight pests and diseases. Many of these chemicals actually are destroying beneficial soil microorganisms and can damage a plant's natural ability to fend off pests and diseases. Additionally, chemical fertilizers can build up in the soil and eventually reduce the overall productivity of the soil.

Organic contents of the soils are constantly reduced by extensive use of chemical fertilizer and repeated farming which is not advised in integrated crop management which leads to deterioration of soil. Further, soil particles become compact and are not able to retain nutrients and moisture due to repeat and overuse of chemical fertilizers. This vicious circle continues when greater amount of chemical fertilizer are required to supplement mineral ions and macro nutrients which are gradually lost. Intensive use of chemical fertilizer is the major cause of imbalance infusion of several micro and macronutrients in soil and has deteriorated soil health, which ultimately has resulted in low productivity and stagnancy in agriculture growth. The major cause of concern towards this low productivity and stagnancy in agriculture growth is the unbalanced infusion of several micro and macro nutrients which are essential for plant growth. For optimum plant growth, nutrients must be available in sufficient and balanced quantities. Excessive and exclusive dependence on potassium based, nitrogenous and phosphatic fertilizers is very harmful to the soil. As a result, overall agricultural productivity is gradually decline.

The constant assault on the land and soil by agricultural and horticultural chemicals is proving to be a major problem, causing imbalances in the amount of essential nutrients in those soils. Thus, the soils are often rendered unsuitable for economically sustained farming and at times the soils have been denatured such that normal levels of plant life cannot be supported.

A wide variety of soil conditioners, which claim to improve a number of soil physical properties are available commercially in the market. However, the successful application and broad spectrum activity of the product is the ma jor issue of concern. U.S. Pat. No. 3,766,685 discloses a soil conditioner produced by fermentation of used tire mesh to produce an oxygen enriched product integrally bonded to the mycelium produced by the fermentation organism Fungi imperfecti.

U.S. Pat. No. 6,752,850 discloses liquid soil conditioning composition of an aqueous dispersion of rock lime and sulfur to improve the agricultural productivity of clay soils. U.S. Pat. No. 4,985,060 discloses a soil conditioner consists essentially of inorganic materials and, according to need, may contain microorganisms capable of eliminating detrimental effects of harmful microorganisms more effectively from the rhizosphere of a crop.

U.S. Pat. No. 5,733,355 discloses bacterial preparation with the ability to produce lipopeptide and cellulosic compounds. The preparation comprised of Members of genus Bacillus and Clostridium.

In spite of all the effort and money being spent in the past, there is a need for better alternatives to current soil treatments which are environmental friendly and are able to ameliorate soils by providing a natural source of NPK as well as other essential minerals and trace elements. It is desirable to create more favourable mediums for plant growth and to conserve soil by improving organic carbon content, soil pH, water-holding capacity, water infiltration rates, aeration and temperature whilst being environmentally acceptable. Thus, the present invention is subjected to the development of microorganisms based conditioner that makes the soil more fertile.

OBJECT OF THE INVENTION

The main objective of the present invention is to provide fungal strains which can effectively improve soil properties. Another objective of the present invention is to develop a synergistic composition comprising one or more of the isolated microbial strains which can improve soil properties.

Another object of the present invention is to develop a composition comprising one or more isolated fungal strains which reduce the harmful effect of chemical amendments on soil caused by chemical fertilizers.

Another object of the present invention is to develop a composition comprising one or more isolated fungal strains which improve the organic carbon content of the soil which thereby improves soil fertility.

It is another object of the present invention to provide a composition comprising one or more isolated fungal strains which neutralize the toxicity of soils and ameliorate soils by providing a natural source of soil enriching elements as well as other essential minerals and trace elements.

Still another object of the present invention is to provide a composition comprising one or more isolated fungal strains which breakdown the complex molecules in soil to make them readily available for crops and also loosen the soil which in turn allows the roots to penetrate in the soil more efficiently.

Still another object of the present invention is to provide a composition comprising one or more isolated fungal strains which enhance the nutrient cycling to make available micro and macronutrient to the plant and also enhances the water holding capacity (WHC). Still another object of the present invention is to provide a composition comprising one or more isolated fungal strain(s) which are optimally formulated to provide a high cfu fungal population with longer shelf life and also increase ion exchange properties of soil.

Still another object of the present invention is to provide a composition comprising one or more isolated fungal strains which possess antagonism against various harmful microorganisms and also provides ideal environment for the growth of beneficial microorganisms and others organisms such as earth worms.

SUMMARY OF THE INVENTION

The foregoing objects have been achieved by isolated fungal strains Trichoderma koningiopsis I1L RAO I. Trichoderma asperellum IIL TAOl and Aspergillus calidoustus I1L ASPCLU04 which are deposited under Nos. TCC 25 186, MTCC 251 85 and MTCC 25187 respectively at the Microbial Type Culture Col lection and Gene Bank (MTCC), Chandigarh, India under Budapest Treaty, impart vital role in improving soil properties. Said fungal strains have gene sequence of SEQ ID NO.: 1 , 2 and 3 respectively. The present invention also sets forth synergistic compositions comprising one or more strains of Trichoderma koningiopsis TIL RA01 , Trichodernw asperellum TIL TA01 and Aspergillus calidoustus IIL ASPCLU04 for improving soil properties.

The concentration of fungal strains in a composition may vary depending upon the carrier used and the target soil/crop. Thus, any suitable concentration that will achieve required enhancing characteristics of soil is desired. In some embodiments, microbial isolate concentration in the composition ranges from about 10⁶- 10^{i 0} microbes per gram in solid composition, about 1 0⁶- 10¹⁰ microbes per milli litre of liquid composition.

In one embodiment, said microbial formulation further comprises suitable carriers, such that the microbial formulation of the present inventions is delivered to soil and crops effectively. The present description is not meant to limit the type of carrier. Indeed, a variety of carriers may be included, comprising but not limited to a liquid, a solid and a combination of a liquid and a solid carrier. In some embodiments, a carrier comprises neutral material but helps in effectively delivering the active components to the target. In some embodiments, a carrier further comprises the substances that maintain shelf life of the microbes. In some embodiments, a carrier comprises adjuvants, stabilizers, emulsifiers, surfactant, additives, suspending agents, cell protectants, buffering agents, wetting agents and/or coating agents.

The invention also concerns, a consortium of one or more strains of Trichoderma koningiopsis IIL RA01 , Trichoderma asperellum IIL TA01 and Aspergillus calidoustus IIL ASPCLU04 that work synergistically to improve soil properties and/or crop yield.

The invention also concerns, a method of large scale production of isolated strains of Trichoderma koningiopsis TIL RA01 , Trichoderma asperellum IIL TA01 and Aspergillus calidoustus IIL ASPCLU04. The species grown in large quantities according to this invention can be used as the active ingredient in the compositions for improving soil properties. Furthermore, the present invention also provides a method for preparing composition comprising one or more strains of Trichoderma koningiopsis IIL RA01, Trichoderma asperellum IIL TA01 and Aspergillus calidoustus IIL ASPCLU04.

DETAILED DESCRIPTION OF THE INVENTION

The following is a description of embodiments of the present invention. The embodiments are in such details as to clearly communicate the invention. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.

To facilitate an understanding of the present invention, a number of terms and phrases as used herein are defined below: Unless the context requires otherwise, throughout the specification which follow, the word "comprise" and variations thereof, such as, "comprises" and "comprising" are to be construed in an open, inclusive sense that is as "including", but not limited to."

As used in the description herein and throughout the claims that follow, the meaning of "a", "an" and "the" includes plural reference unless the context clearly dictates otherwise.

In some embodiments, the numerical parameters set forth in the written description are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment.

As used herein, "microorganism" refers to any species or type of microorganism, including but not limited to, bacteria, archaea, fungi, protozoans, mycoplasma, and parasitic organisms.

As used herein, "fungi" includes eukaryotic organisms such as the molds and yeasts, including dimorphic fungi, fungi found in soil, and any fungi found growing on a plant.

As used herein, "cfu" refers to a colony forming unit.

As used herein, "accession number" in reference to "having an accession number" refers to a number assigned to a cultured isolate upon deposition to a recognized depository.

In one preferred embodiment, the microorganisms, preferably fungal strains are in isolated form. As used herein, the term "isolated" means isolated from its native environment without any impurities.

The present invention is directed towards microorganisms that are selected from one or more of bacteria, fungi, yeast or any combination thereof. As per one of the embodiment of the present invention, microorganisms are selected from the class of fungi from various sources.

In one of the embodiment, the present invention is directed to isolated fungal strains Trichoderma koningiopsis IIL RAOl , Trichoderma asperelli n IIL TA01 and Aspergillus calidouslus IIL ASPCLU04 which impart vital role in improving soil and crop properties/productivity are deposited under Nos. MTCC 25 1 86, MTCC 25 185 and MTCC 25187 respectively at the Microbial Type Culture Collection and Gene Bank (MTCC), Chandigarh, India.

As per one of the embodiment of the present invention, the present invention describes the synergistic soil improving composition having one or more of said isolated fungal strains Trichoderma koningiopsis IIL RAO l , Trichoderma asperellum IIL TA01 and Aspergillus calidouslus IIL ASPCLU04 which are deposited under Nos. MTCC 25186, MTCC 25185 and MTCC 25187 respectively at the Microbial Type Culture Collection and Gene Bank (MTCC), Chandigarh, India, impart vital role in improving soil properties. A composition may be in any form, such as a liquid, solid, i.e. dried formulation, wettable powder, and in some embodiments, applied with one or more agriculturally acceptable carrier.

In accordance with one of the embodiment of the present invention, individual fungal strain of Trichoderma koningiopsis IIL RA01 , Trichoderma asperellum IIL TA01 and Aspergillus calidoustm IIL ASPCLU04 or consortium comprising two or more of said fungal strains is provided in a suitable composition to apply to the soil directly or the soil surrounding the plants. The suitable carriers used in the invention may include inert material, growth supporting substances and the substances that maintain long shelf life of the fungal strains. In accordance with one of the embodiment of the present invention, the strain isolation is done from various resources such as cow-dung and rhizospheric soil.

In accordance with one of the embodiment of the present invention, the fermentation material such as farm yard manure/agricultural waste/organic waste/compost/various types of flours with sugar/jaggery/molasses/sugarcane juice/sorghum etc may be used in the present invention.

In accordance with one of the embodiment of the present invention, the soil conditioning composition contains fungi, which has a total viable cell count in the range of about 1 x 10⁶ to 1 x 10¹⁰ cfu/g or cfu/ml.

In accordance with one of the embodiment of the present invention, the application procedure was optimized along with dose required for one hectare of land.

In accordance with one of the embodiment of the present invention, the concentration of any of strain of fungi Trichoderma koningiopsis IIL RA01 , Trichoderma asperellum. IIL TA01 and Aspergillus calidoustus IIL ASPCLU04 or consortia of any two or all three fungal strains in the composition is from about 0.5 to 80 percent by weight of all components in the composition.

In accordance with one of the embodiment of the present invention, wherein the composition comprising fungal strains of Trichoderma koningiopsis IIL RA01 and Trichoderma asperellum IIL TA01 , the weight ratio of Trichoderma koningiopsis IIL RA01 to Trichoderma asperellum IIL TA01 is about 1 :80 to 80: 1 .

In accordance with one of the embodiment of the present invention, wherein the composition comprising fungal strains of Trichoderma koningiopsis IIL RA01 and Aspergillus calidoustus IIL ASPCLU04, the weight ratio of Trichoderma koningiopsis IIL RA01 to Aspergillus calidoustus IIL is about 1 : 80 to 80: 1 .

In accordance with one of the embodiment of the present invention, wherein the composition comprising fungal strains of Trichoderma asperellum IIL TA01 and Aspergillus calidoustus IIL ASPCLU04, the weight ratio of Trichoderma asperellum IIL TA01 to Aspergillus calidoustus IIL ASPCLU04 is about 1 :80 to 80: 1. In accordance with one of the embodiment of the present invention, wherein the composition comprising fungal strains of Trichoderma koningiopsis IIL RAOl, Trichoderma asperellum I1L TA01 and Aspergillus calidoustus IIL ASPCLU04, the weight ratio of Trichoderma koningiopsis IIL RA01 to Trichoderma asperellum IIL TA01 to Aspergillus calidoustus IIL ASPCLU04 is about 1 : 1 : 80 to 1 :80: 1 to 80: 1 : 1.

In accordance with one of the embodiment of the present invention, a method of preparing the soil improving composition comprising the steps of:

(i) Isolating fungal strains, Trichoderma asperellum IIL TA01 , Trichoderma koningiopsis IIL RAOl or/and Aspergillus calidoustus IIL ASPCLU04;

(ii) Sub-culturing the fungal strains on suitable media,

(iii) Preparing inoculums of the strains;

(iv) Fermenting the strains;

(v) Isolation/harvesting of the strains; and

(vi) Drying the strains.

In accordance with one of the embodiment of the present invention, a method of applying the soil improving composition comprising the steps of:

(i) Multiplication of strains Trichoderma asperellum IIL TA01 , Trichoderma koningiopsis IIL RAO l or/and Aspergillus calidoustus IIL ASPCLU04 as present in the composition in suitable media; and

(ii) Contacting the strains to soil or/and plants. It is found that isolated strains Trichoderma koningiopsis IIL RAOl, Trichoderma asperellum IIL TA01 or/and Aspergillus calidoustus IIL ASPCLU04, consortia thereof, and composition comprising one or more of said strains enriches soil properties such as ion exchange properties, water holding capacity, corrects pH, increases soil organic carbon, provide a natural source of macro and micro elements, loosen the soil, breakdown the complex molecules in soil, enhance the nutrient cycle, possess antagonism against various harmful microorganisms, promotes growth of beneficial organisms that re-establish a healthy soil and allow plants to thrive.

EXAMPLES

The inventions are now described and illustrated with the following non-limiting examples. Isolation of microbes

Isolation of soil conditioning fungi was performed based on various abilities of microbes such as to decompose cellulose and lignin or their habitats where cellulose rich compostable material is present. The isolation was performed from fresh or/and partially composted cow dung and from rhizospheric soil which was earlier treated with fresh or/and partially composted cow dung by serial dilution method on SDA/PDA plates and incubated at 30 ± 3°C.

Isolation of soil conditioning fungi from fresh and composted/ partially composted cow dung was performed using moist chamber method. The cow dung was kept in moist chamber plates equidistantly with wide space for the growth of fungi and were incubated for 5-15 days at 30 ± 3°C for fungal growth and sporulation. A direct isolation method was carried out by using fine sterile needle to pick up the fungal hyphae and spores from the dung surface under a stereomicroscope and transfer on sabouraud dextrose agar (SDA) or potato dextrose agar (PDA). Isolation of soil conditioning fungi was also performed from rhizospheric soil of wheat, paddy, and fruit plants by serial dilution of rhizospheric soil on SDA/PDA plates and incubation at 30 ± 3°C.

Most of the samples of rhizospheric soil, cow dung and rhizospheric soil which was earlier treated with fresh or/and partially composted cow dung were obtained from Kheri Karmu, Shamli, Uttar Pradesh. Fungi were also isolated from wheat, paddy, local seasonable crops and fruit plants of Shamli (UP) and nearby area of Shamli.

Screening of microbes and molecular identification thereof:

Screening of best isolated strains was done on the basis of soil enriching, crop growing and other useful properties for agricultural purposes. Out of all isolated microbial strains, three strains were found best and identified as Trichoderma koningiopsis 11L RA01 , Trichoderma asperelliim IIL TA01 and Aspergillus calidoustus IIL ASPCLU04. Said fungal strains have gene sequence of SEQ ID NO.: 1, 2 and 3 respectively.

All the three best isolated fungal strains i.e. Trichoderma asperellum I1LTA01 , Trichoderma koningiopsis IILRA01 and Aspergillus calidoustus IILASPCLU04 were subjected to mass production by following process (Here 1ILTA01 , 11LRA01 and 11LASPCLU04 is research lab code number of isolate Trichoderma asperellum, Trichoderma koningiopsis and Aspergillus calidoustus respectively)

(a) The isolates were first cultured on PDA/SDA agar plates and incubated at 30°C for 7 days.

(b) After 7 days, fungal growth of incubated plates was transferred to sterile normal saline to prepare spore inoculums of >1 x 10⁸ /ml and thereafter fermentation was performed in either of the following ways:

1. Submerged fermentation (SF): Soil conditioning fungi inoculums of > 1 x 10^s /ml 1- 10 % by mass transferred in sterile jaggery yeast medium (jaggery 30 g/1, yeast extract 5 g/1) and kept at incubation for 7 to 30 days at 30±2°C. After 7 to 30 days same or separated mycelium and spore mass was harvested or sieved through 350 BSS sieve. II. Solid state fermentation (SSF): Soil conditioning fungi inoculums of > 1 x 10 /ml 1 - 1 0 % by mass transferred in sorghum soaked overnight in 2 % sucrose solution and sterilized in polypropylene bags and kept at incubation for 7 to 30 days at 30±2°C for solid state fermentation. After 7 to 30 days, sucrose soaked sorghum was found to be full of growth of soil conditioning fungus.

Alternatively dry spore and conidia production can be performed using jaggery yeast agar media (Jaggery 30g/l, Yeast 5g/l and agar 1 8g/l) or PDA (Potato infusion of 200gm peeled potato, Dextrose 20gm and agar 15gm) or yeast peptone glucose agar media (Peptone l g/1, Yeast extract 3g/l, Dextrose 20g/l and agar 1 8.5g/l) followed by steri lization at 121 °C and 1 5 psi steam pressure for 20 minutes and poured in pre sterile trays and then inoculated with 1-10 % individual soil conditioning fungi of strength >lx 10⁸'ml followed by incubation for 7 to 30 days at 30°±2 °C and finally harvesting the growth (spores and conidia of soil conditioning fungi) using scraper and mixed with dextrose or soap stone powder followed by drying in FBD at temperature not exceeding

42°C

For powder/ granule or carrier based formulation either harvested spore from dried SSF and/or processed pulverised soil conditioning fungi either from SF or SSF was mixed with carrier (soapstone powder and/or eoline and/or Dolomite etc), For liquid formulation (AS or SC) harvested mycelium and spore from SF or SSF was mixed in normal saline or Glycerol or paraffin oil or Poly ethylene glycol or different combination of normal saline, Glycerol, paraffin oil and Poly ethylene glycol.

In addition to the powder or liquid carrier several components like shelf life stabilizer (Dextrose and/or glycerol and/or lactose and/or Trihalose etc.), sticking agents (carboxy methyl cellulose [CMC] and/or Guar gum and/or starch etc.), cell protectants (PVP 30 and/or Ectoin and/or etc., adjuvants (Hydrolyzed protein and/or L-methyle folate and/or Pyridoxyl 5-Phosphate [P5PB6], and/or Pyrroloquinoline quinine etc.), wetting agents (Tween 20 and/or Tween80 and/or Triton XI 00 etc.) and suspending agent (Bentonite powder and/or Xanthan Gum and/or Gum acacia etc) were also used. The quality report of one of such sample in revealed the following Table 1 :

Characteristics Composition

Physical Moisture content 08%

characterstics Particle size 100 micro m

Chemical pH 7.0

characterstics

Microbial Individual Viable Cell count:

characterstics

2 x 10⁹ cfu/g cellulose 1.5 x 10^y cfu/g lignin

Total viable cell count 3.5 x 10^y cfu/g

Contamination Nil

Table: 1

Various methods can be used for application of the composition of the present invention in the field. As per one of the embodiment, following method is adopted for application of the composition of the present invention in the field:

Before one week of irrigation farmer should practice the following procedure:

Take 2 Kg of Jaggery (Gud/Raw sugar/Molasses)

Mix in 200 Liter of water in a plastic drum.

• Add about 100 gram/100 ml composition to the above solution and mix well for 5- 10 minutes.

· Allow standing for 5-7 days with everyday intermittent mixing for 5- 1 0 minutes.

After 5-7 days there will appear white to green colored growth in the liquid and colour of solution will change.

This prepared liquid may be directly applied through flood irrigation or drip irrigation or soil drenching in one acre field.

From various trials performed, it was found that not only do these strains exhibit excellent properties individually they also work together, showing synergism in a consortium of two or more strains. The consortium is stable, overall one strain does not affect the advantageous /good properties of the other and shows unexpected soil improving properties, including improved ion exchange properties, water holding capacity, corrects pH, increases soil organic carbon, provide a natural source of several micro and macronutrients, loosen the soil, breakdown the complex molecules in soil, enhance the nutrient cycle, possess antagonism against various harmful microorganisms, promotes growth of beneficial organisms that reestablish a healthy soil and/ or allow plants to thrive. Few of trials as performed are represented herein below:

Enzyme secreting potential of the isolated fungal strains Trichoderma koningiopsis 11LRA01 , Trichoderma asperellum 1ILTA01 and Aspergillus dadioustus I1LASPCLU04 and their consortium was investigated. It was found that the isolated strains and their consortium exhibited excellent potential of secreting various plant growth promoting enzymes such as cellulase, amylase, lipase, uricase, urease, nitrate reductase, catalase and protease. They also produced siderophores that helps in inhibiting plant pathogens and thereby indirectly accelerates plant growth and makes the crop disease free. Increase in 1AA production (3.1 μg/ ml) was found in the microbial consortium in comparison to the individual strains {Trichoderma koningiopsis I!LRA01 - l ^g/ml, Trichoderma asperellum llLTAO l - 1.6 μg/ml and Aspergillus cladioustus. IILASPCLU04 - 2.9 μ^πιΐ) which is vital for crop productivity. The following Table 2 shows some of the beneficial enzymes and hormones secreted by Trichoderma asperellum IILTA01, Trichoderma koningiopsis IILRA01 and Aspergillus cladioustus IILASPCLU04 and their consortium

Table 2. Potential of isolates for secreting beneficial enzymes and hormones. Pot level studies of all the isolates and their consortia were also performed for various plants such as sorghum, wheat and maize. The following Table 3 gives an insight of the acceleration in plant growth, after inoculation with individual strains and as well as consortia thereof.

Table 3. Plant growth parameters after inoculation with isolated fungal species and their consortia.

A field level trial was performed to investigate the potential of the consortium of the present investigation in the yield of various vegetables. For example, for potato, capsicum and bitter gourd, an increase in weight were recorded for all of them and results as represented herein in below Table 4.

Vegetable Without consortium With consortium

treatment treatment

(Kg/plant) (Kg/plant)

Potato 3.656 4.130

Capsicum 0.940 1.080

Bitter gourd 0.550 0.780 Table 4. Increase in weight of potato, capsicum and bitter gourd as a result of treatment with consortium

Several field level trials were performed at various sites to check the improvement of various soil parameters. For example, following data is obtained from the trials as performed in soil ofKarnatka:

Table 5. Changes in various soil parameters as a result of inoculation with the consortia.

From the above Table 5, it is evident that all the soil factors/parameters get improved by treating it with composition comprising consortium of the present invention. Especially, soil organic carbon (SOC) is the most critical factor for soil structure and physical properties, nutrient availability to plant, biological soil health, buffer against toxic and harmful substances and good productivity. Improvement in only 0.1% in SOC may convert 4.2 Ton atmospheric carbon to organic carbon when sampling depth is 30 cm, therefore it also play a vital role in reducing global warming and climate change.

The antagonistic activity of all three isolated fungus Trichoderma asperellum 11LTA01, Trichoderma koningiopsis IILRA01 and Aspergillus calidoustus IILASPCLU04 and of their consortium was also performed against many pathogens such as Rhizoclonia solani, Macrophomina ph seolina and Fiisarium oxysporum and it was found that they possess good antagonistic activity as well. The results of one of such trial are presented in below Table. 6.

Pathogens

Isolates R. solani F. oxysporum M. phaseolina

% inhibition

T. asperellum 100 66.67 100

T. koningiopsis 100 100 85.78

A. calidoustus 100 100 100

Consortia(T. asperellum, T. koningiopsisand A.

Calidoustus) 100 100 100

Table 6. % inhibition of isolates against selected pathogens

Further, it was also found that the pesticidal activity of consortia works effectively in low dosage than the dosage as required of individual strains to inhibit same pathogen.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications may be made thereto.

Claims

WE CLAIM:

1) An isolated fungal strain selected from Trichoderma asperellum IIL TA01 having accession number MTCC 25185, Trichoderma koninglopsis IIL RA01 having accession number MTCC 2 186, and Aspergillus calidoustus IIL ASPCLU04 having accession number MTCC 25187.

2) The isolated strains as claimed in claim 1, wherein said strains have soil improving, crop improving and pesticidal properties.

3) A consortium comprising two or more strains selected from Trichoderma asperellum.

IIL TA01 having accession number MTCC 25185, Trichoderma koninglopsis IIL RA01 having accession number MTCC 25186, and Aspergillus calidoustus IIL ASPCLU04 having accession number MTCC 25 1 87.

4) A soil improving composition comprising one or more isolated fungal strain selected from Trichoderma asperellum IIL TA01 having accession number MTCC 25185, Trichoderma koninglopsis IIL RAOl having accession number MTCC 25186, and Aspergillus calidoustus IIL ASPCLU04 having accession number MTCC 251 87.

5) The soil improving composition, wherein the composition is in solid or liquid form.

6) The soil improving composition as claimed in claim 4, wherein the fungal strains are present in the range of about 1 x 10⁶ to 1 x 10¹⁰ CPU in per gram/ml of the composition.

7) The soil improving composition as claimed in claim 4, further comprising one or more agriculturally acceptable carrier.

8) The soil improving composition as claimed in claim 4, wherein said agriculturally acceptable carriers are selected from adjuvants, stabilizers, emulsifiers, surfactant, additives, suspending agents, cell protectants, buffering agents, wetting agents and/or coating agents.

9) The soil improving composition as claimed in claim 4, wherein the composition comprises fungal strains of Trichoderma koninglopsis IIL RAO l and Trichoderma asperellum IIL TA01 , and wherein the weight ratio of Trichoderma koninglopsis IIL RAOl to Trichoderma asperellum IIL TA01 ranges from about 1 :80 to 80: 1.

10) The soil improving composition as claimed in claim 4, wherein the composition comprises fungal strains of Trichoderma koninglopsis IIL RAOl and Aspergillus calidoustus 11L ASPCLU04, and wherein the weight ratio of Trichoderma koningiopsis IIL RAO l to Aspergillus calidoustus II L ranges from about 1 :80 to 80: 1.

1 1 ) The soil improving composition as claimed in claim 4, wherein the composition comprises fungal strains of Trichoderma aspereUum IIL TAO l and Aspergillus calidoustus IIL ASPCLU04, and wherein the weight ratio of Trichoderma aspereUum IIL TAO 1 to Aspergillus calidoustus IIL ASPCLU04 ranges from about 1 :80 to 80: 1 .

12) The soil improving composition as claimed in claim 4, wherein the composition comprises fungal strains of Trichoderma koningiopsis IIL RAO l , Trichoderma aspereUum IIL TAO l and Aspergillus calidoustus IIL ASPCLU04, and wherein the weight ratio of Trichoderma koningiopsis TIL RAO l to Trichoderma aspereUum IIL TAO l to Aspergillus calidoustus IIL ASPCLU04 ranges from about 1 : 1 : 80 to 1 :80: 1 to 80: 1 : 1.

1 3) A method of preparing the soil improving composition as claimed in claim 4, comprising the steps of:

(i) Isolating fungal strains, Trichoderma aspereUum IIL TAO l , Trichoderma koningiopsis IIL RAOl or/and Aspergillus calidoustus TIL ASPCLU04;

(ii) Sub-culturing the fungal strains on suitable media,

(iii) Preparing inoculums of the strains;

(iv) Fermenting the strains;

(v) Isolation/harvesting of the strains; and

(vi) Drying the strains.

14) A method of applying the soil improving composition as claimed in claim 4, comprising the steps of:

(i) Multiplication of strains Trichoderma aspereUum IIL TAO l , Trichoderma koningiopsis IIL RAO l or/and Aspergillus calidoustus IIL ASPCLU04 as present in the composition in a suitable media; and

(ii) Contacting the strains to soil or/and plants.