Review Article On Biofertilizers

Review ABSTRACT: One of the challenges of globalization to developing countries is to increase agricultural production quantitatively but also to improve the quality of the product so that it can go well in the world market. Agrochemicals responsibible for making India self sufficient through Green revolution are no longer able to sustain the productivity to the extent on account of all the ill-effects it had on the agro system during the process. Biofertilizers i.e. Biological Based Product are most advanced biotechnology necessary to support developing organic agriculture sustainable agriculture, green agriculture and non-pollution agriculture.

1. Introduction: During the past four decades we have witnessed doubling of human population and a concurrent doubling of food production. On the contrary we have entered the third millennium with more than a billion people and we are facing a Herculean task of providing food to this rapidly increasing population particularly in developing country like India [Dhaliwal And Arora, 2003].(2) To cope up with the need of increasing the agricultural productivity in accordance with the population and to improve the quality of the product in terms of nutritional value has resulted in misuse and excessive use of chemical fertilizer. Poorly managed use of these chemical N and P fertilizers have created several environmental problems such as deterioration of soil quality, leaching, acidification ,denitrifiction,air pollution, reduced biodiversity, disrupting the fragile ecosystem.(1,2). Thereby to overcome these ecological problems, to minimize the use of chemical fertilizers we are now directing ourselves towards the potential use of ecofreindly approaches such as the use of Biofertilizers and Biopesticides to sustain high production, allow more efficient nutrient utilization and thereby provide solutions for present and future agricultural practices. In this review article a brief overview on the potential use of 1

“Biofertilizer”a Biological Based Product as an alternative for sustainable agriculture is being discussed.

2)What are Biofertilizers? Biofertilizers are natural and organic fertilizers.Biofertilizers are preparations containing cells of microorganisms which may be nitrogen fixers, phosphorus solublizers, sulphur oxidizers or organic matter decomposers. They are called as bioinoculants-bacterium or fungi which on supply to plant improve their growth and yield. (13) These bioinoculants can reside on the surface of the plant or form endophytic association or else interacts with other microbes in the rhizosphere or phyllosphere thereby influencing the plant growth. Production of chemical fertilizers require fossil fuel energy while microbes do not thereby proving to be cost effective ecofreindly with the simple methodology of production and thereby no hazard to the agro ecosystem(13,10) Biofertilizers thereby might assume a special significance towards development of strategies for improving productivity and economizing the production cost, minimizing our dependence on synthetic chemical fertilizers. Let us move towards a more comprehensive description of microbial biofertilizers. The most limiting nutrient for plant growth are Nitrogen(N) and Phosphorus(P).Some microorganisms used as Biofertilizers fix atmospheric Nitrogen and while others increase availability and uptake of nutrients such as ‘P’and other key micronutrients such as copper,manganese,molybdenum etc.Thereby these Biofertilizers increase the crop yield tremendously.

3] N2 Fixing Bacteria as Microbial Biofertilizers: Air consists of approximately 80% nitrogen gas (N2), representing about 6400 kg of N above every hectare of land. However, N2 is a inert, stable gas, normally unavailable to 2

plants. Although abundant and ubiquitous in the air Nitrogen is the most limiting nutrient for plant growth because the atmospheric N is in the most stable form and is therefore not available for plant uptake. Most of N is tied up in soil organic matter. Symbiotic and nonsymbiotic microorganisms have the ability to fix N2 and convert it into NH4+, a form that can be easily absorbed by plants. These organisms convert the atmospheric Nitrogen into ammonia and amino acids which can then be used up by plants to build up proteins. This process is known as “Biological Nitrogen Fixation”. (11) The close proximity of these microorganisms to their host plants allows efficient of fixed N. These bacteria capable of N2 fixation are of following types:1) There are many free living N2 fixing bacteria in soil. 2) Some have adapted to symbiosis; intimate endophytic association with plants. 3) Some live in close association in the plant root zone (rhizosphere) without forming intimate endophytic symbiosis. Let us evaluate their use as biofertilizers. I) Symbiotic N2 fixers: (1) Rhizobia:The best known and most exploited symbiotic N2 fixing bacteria belonging to family Rhizobiacea include the genera such as Rhizobium, Bradyrhizobium etc.These bacteria infect legumes and have global distribution. However N2 fixing capability of Rhizobia varies greatly depending on the host plant species. Therefore selection of best strains must take Rhizobia host compatibility for selection of Biofertilizers. (13, 11) Legumes (such as beans, soybean, chickpea) inoculation is an old practice that has been carried out especially when local/resident rhizobial population in the soil are low.Rhizobial inoculum can be produced and applied in numerous ways such as granular, liquid or powder formulation. (11) However the success depends upon strain and environmental condition. Therefore it is essential to evaluate inoculation programme, type depending on field experiments, microbiological assays and cost benefit analysis. 3

2) Frankia: Frankia is the genus of N2 fixing actinomyctes capable of fixing N2 similar to rhizobial symbiosis. Frankia can fix N2 at normal O2 concentration at the rate sufficient to support its growth N2 fixation is accompanied by the development of terminal swelling known as vesicles in which nitrogenase enzyme are protected by restrictingO2diffusion. In addition to symbiotic properties of strain characteristics such as age of the inoculum cellular concentration and the method of preservation greatly effect the inoculum infectivity. (11) Since a universal strain adapted to different environmental host genotype does not exist, best plant Frankia combination should be selected and customized for a target area and target species. 3) Cyanaobacteria: Cyanaobacteria are ecologically important in N2 fixing organisms especially in rice cultivation. Anabaena azollae is a symbiotic heterocyst nitrogen fixing Cyanaobacteria which lies in fronds in the pores of the Azolla.(6) Contribution of the Cyanaobacteria to Total N uptake by rice seedlings was assessed using free-living and immobilized A.azollae in the presence of different combined Nitrogen sources using 15 N dilution technique.(6)

Methods(6) The cyanobiont Anabaena azollae(AS-DS )is grown in N free BG-11 medium azollae immobilized on Polyurethene(PUF) and Sugarcane waste(SCW) was used for this study. 30 days grown free living and immobilized Cyanaobacterial culture were used as inoculants. A Paddy seed (cultivar ADT36) were soaked for 12 hours in water and was later on allowed to sprout. The freely living and immobilized A.azollae were then inoculated in Nfree medium at 500 mg fresh weight Cyanaobacterial biomass along with sprouted seeds. The combined N2 in the form of urea, potassium nitrate and ammonium sulphate with 10% atom excess 15N was added at to the growth medium at weekly intervals. After 30 days rice seedling were dried, powdered, total N was determined by micro-Kjeldahl digestion and distillation method and Mass spectrometry.

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The percent N derived from combined nitrogen source ( %Ndff) and percent N derived from Cyanaobacteria (%Ndfc) of total N content of rice seedlings were calculated using the formula. %Ndff=Atom percent excess 15 N in inoculated plant*100/Atom percent

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N in uninoculated plant

%Ndfc=100-%Ndff Effect of inoculation of A.azollae (AS-DS)with different Combined Nitrogen on total N content and 15N recovery in rice seedlings. 15

Total N

N recovery

(mg plant) (atom excess %) Cyanaobacterial Combined N source Combined N source Contro Potassium urea NH4 Potassium urea NH4 culture

Free living

l

nitrate

1.2

3.9

5.9

SO4

nitrate

SO4

1.5

3.29

3

2.77 2.74

PUF immobilized

1.4

4.3

6.5

1.5

3.15

.89 3

SCW immobilized

1.4

4.6

7.8

2.3

2.96

.82 3

2.75

4.69

.69 4

3.11

Uninoculated

0.6

3.9

3.5

Control Interaction(p<0.05)

2.4

0

.80 0

.19

.24

Result: SCW and PUF immobilized cyanobacterial inoculation recorded 28% and 16% more N2 in rice seedlings than free living culture. Among combined N2 sources urea was more superior followed by potassium nitrate and ammonium sulphate in terms of N2 uptake. The N2 uptake by immobilized culture was much higher than free living culture which was higher compared to uninoculated culture. Thereby we could conclude that immobilized cyanobacterium in combination with urea has contributed more biologically fixed N2 to the crop.

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Exploitation of azolla as a biofertilizer is a practical possibility in flooded soil condition. It is used as both green manure before planting and intercropped with rice after planting. The latter practice has wide adaptability and is more economical as Azolla decomposes within two weeks releasing about 67% of Its N.The increase in grain yield due to Azolla green manuring is about 0.5-2 tonnes per hectare. Thereby cyanobacteria should be seriously considered as biofertilizer with a great potential as these cyanobacterial (especially immobilized) have resulted in higher heterocyst frequency growth,nitrogenase activity and increased ammonia excretion and have also increases availability of micronutrients like iron. manganese in the soil.(6,9,11)

II] N2Fixing associated Bacteria: In addition to symbiotic bacteria infecting plant roots, numerous taxa of less intimately associated N2 fixing bacteria can be considered for crop yield improvement such as Acetobacter, Azospirullum, Bacillus, Pseudomonas, Enterobacter etc. 1) Azospirillum This genus includes spirally curved bacteria which not only lives in rhizosphere of grasses but can also enter root cortex. It is an associative micraerophilic Nitrogen fixer which not only colonizes root mass and fixes N2 in close association with plant in an environment of low O2 tension. These bacteria induce plant roots to secrete mucilage substances which creates low O2 environment and helps to fix atmospheric Nitrogen.It has a wide host range, high N2 fixation capacity, low energy requirement, tolerance to high soil temperature thereby makes these suitable for tropical condition.(13) The positive aspect of this inoculant is that they produce plant growth promoting substance in addition to fixing the Nitrogen and has ability to differentiate into cyst under stress that enables its persistence for a long time in field condition.Azospirillum bears great promise as a growth promoting Nitrogen fixing biofertilizer.It has been recorded that Azospirillum inoculation may be used as biofertilizer for wheat ,rice thereby reducing use of urea N by approximately 20%(9,11). Along with its growth promoting properties its commercial production is inexpensive as inoculum produced can be applied as peat formulation which can be directly

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utilized in field research and agricultural applications. However for alternative carriers and application procedures needs further research. 2)Acetobacter: It is a non symbiotic (micrsymbiont) bacteria which is mostly associated with sugarcane crop. It grows inside the root as well as stems to some extent and fixes atmospheric nitrogen and benefits the crop. It is rather difficult to isolate the organism and grow artificially on a large scale.(3,13) Therefore the potential of it as a biofertilizer will depend on finding suitable techniques to grow it fastly in laboratory. If this is done successfully we may save huge quantity of chemical nitrogenous fertilizers. 3) Klebsiella: They fix N2 under anaerobic condition as these have no means of protecting nitrogenase enzyme from O2.These organisms have flexibility to grow under both aerobic and anaerobic environment. In the laboratory Klebsiella has been shown to reproduce Nitrogen under micraerophilic condition(11). Therefore use of Klebsiella as a biofertilizer will require several field trials and future research. 4) Bacillus Nitrogen fixing Bacillus Polymyxa and Bacillus macerans were isolated from cotton phylloplane.These bacteria show an increase in yield of cotton due to its ability to fix nitrogen produce Indole Acetic Acid and Gibberelic acid production. The foliar spray on this phylloplane bacteria was showing an increased growth,yield,increased Nitrogen fixation and an increased chlorophyll ,nitrogen, phosphorus content.(7,11,13) Similarly Bacillus subtilis inoculation on chilli plant through the phyllosphere have resulted in increase in chlorophyll content ,photosynthetic quotient and eventually increased growth.(1) III] Free living N2 fixing Bacteria:

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Many free living bacteria also fix atmospheric N2.Example includes Azotobacter, Beijerinckia and Clostridium. 1)Azotobacter:: This is a group of bacteria which are free living nitrogen fixer. Sufficient research work has been carried out on the role of Azotobacter culture in sugarcane cultivation. The result in general have indicated that application of Azotobacter at the rate of 5kg per hectare helps in reducing nitrogen dose by 50kg per hectare with increase in yield of cane by 5 to 10 %. The mechanism by which plants inoculated with Azotobacter derive its benefits such as increased biomass ,Nitrogen uptake is attributed to increase in nitrogen input by Biological nitrogen fixation, development and branching of roots ,production of plant growth hormones,vitamins,enhancement in uptake of nitrate, ammonium orthophosphate, potassium and iron improved water status of the plant and antifungal compounds.(3,11,13) If environmental conditions allow nodulating bacterial symbionts (ex Frankia) of plant roots can also fix N2 when not in symbiotic association. Estimation of Nitrogen fixation by free-living bacteria is difficult.

2.Phosphorus solubilizing bacteria : Phosphorus is the second most limiting plant nutrient required for better crop yield. Indian soil contains on an average 0.05% Phosphorus which constitutes 0.2%dry weight.(5) Most of the soil Phosphorus pool is not in forms available for plant uptake or the soil might contain insufficient amount of available phosphate to support plant growth. As a result of application of phosphatic fertilizer is therefore essential for optimum crop yield. However the main problem concerning phosphatic fertilizer is that its fixation with soil complexes within a very short period of application rendering more than two third unavailable.(9,11,13) Many organisms possess the ability to bring sparingly soluble/insoluble inorganic and organic Phosphorus into soluble forms by secreting organic acids. These organic acids lower soil pH and in turn brings about dissolution of unavailable forms of soil Phosphorus making it available for plant growth and development. Some of the hydroxyl 8

acids may chelate calcium, Aluminium,Iron and Magnesium resulting in effective availability in soil. Use of Phosphate solubilizing bacteria as bioinoculants could reduce the phosphate dose by 50% and could be applied in the form of Rock phosphate which is cheaper source of Phosphorus.(1,9) The most commonly tested organisms of this group belong to the genera Bacillus and Pseudomonas. There were two method of phosphobactrium application i.e. seed treatment (500ginoculum per hectare) and soil application (200g per hectare).(9) Pretreatment of seeds of cereals with phosphobactrium has been reported to help in reducing fertilizer phosphate requirement of the crop and increasing its grain yield.

Potential use as Biopesticide: Although extensive research has been made on utilization of Phosphorus solubilizing bacteria in order to provide soluble forms of phosphate to plants while some of them were found to release antifungal compounds. An attempt in this direction was made to screen 25 bacterial cultures from the rhizosphere of various crop and culture of Pseudomonas striata(P-27 for their antifungal activity against Asperigillus niger),Fusarium oxysporum,Pythium aphanedermatum,Curvularia lunata and Rhizobia solani by Spot test method. Spot test method: Bacillus culture were spotted on Luria Bertani plates preseeded with respective fungal spores all the bacteria showed large variation (0 to 130%) in inhibition of different fungi. Of them four cultures 6P, 10P, 12P, 14P showed broad range of antifungal activity against all the fungal pathogens. Rest of the culture showed variable activity against organisms or no inhibition. (5)

Therefore Phosphorus solubilizing bacteria like these with antifungal activity could be exploited as biofertilizer as well as biopesticide.The combination of the above 2 attributes will be of great advantage in crop production.

5] Fungi and their potential as biofertilizer:

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Mycorhizal fungi form mutualistic symbiosis with a wide variety of plants.ie fungi infects the plant roots. Three general types of Mycorrhizae are known such as Ectomycorrhizae, Endomycorrhizae and endoectomycorrhizae.

Vesicular Arbuscular Mycorrhiza: They are obligate symbionts that occur in 90% of vascular plants. It improves plant growth and enhances the uptake of more nutrients generally unavailable to host plant especially ‘P’ from soil. It also increases the water uptake or alters plant physiology to reduce stress response to soil drought. It can also withstand high temperature, increase heavy metal tolerance of plants as well as make the plant less susceptible to root pathogens. VAM may also prove useful in successful establishment of micro propagated plantlets in field who face difficulty due to their weak root system and transplantation shock.Microprpogation is a powerful tool in plant tissue culture. VAM (Glomus fasciculatum) infected micro propagated plants i.e. exvitro (adding spores in plants)and invitro VAM infected plants were transferred to polyurethane bags containing field soil and then maintained in glasshouse. In the field sandy soil having low levels of ‘P’ ,using one half and three fourth recommended dose of phosphorus were applied along with recommended urea dose of 325kg per hectareUninoculated micro propagated plants served as control. RESULTS: Colonization of invitro grown sugarcane roots by VAM Days after Inoculation

% Colonization

10 48 20 68 30 78 Thus Colonization was maximum after 30 days cocultivation.Root Dry weight was more invitro VAM infected plant is 2.45g than 1.97 g for control. These plants almost two fold increased root biomass than control plants in addition to better survival rate of 89.6% than non mychorrizal plant. Thus field investigation revealed that successful mychorrhization improved survival rate, 25% saving of phosphatic fertilizer by proving strong rooting system and improved growth along with improved crop quality i.e. sugar content, cane height, cane yield. 10

.(3,13)Though the role of VAM in improving plant growth and nutrition is an established fact, field application of these obligate fungi has remained limited due them being an obligate parasite. Some ectomycorrhizae like Pisolithus tinctorius could be surveyed for its use because they generally have host range, extensive geographic distribution. Hence they could be considered for commercial exploitation.

Multiple/Co Inoculation among potential Biofertilizers : This refers to the practice of inoculation and introduction of more than one fungus and /or bacterium into target crops as Multiple/Co Inoculation. Different combinations of organisms are being tested against different crops. A field study was conducted on three microbial biofertilizers ie Premium Azotoplus(Azotobacter),Premium Azosphiplus(Azospirillum)and Premium Phosphofix(Phosphate Solubilizing Bacteria)on wheat, mustard each singly or in combination The results obtained when 3 were used

singly on wheat, mustard was in the range10-

16%,18-19% respectively.Whereaes when used in combination they not only increased the yield tremendously but lowered doseie250ml per gram per acre is recommended for each of biofertilizers in combination taking into consideration cost: benefit ratio.(12) Cereals such as rice constitute major fraction of poor mans diet in most Asian countries including India. Application of inorganic fertilizers have brought about an spectacular increase in crop production but over a long period of time have resulted in imbalanced supply of nutrients, affecting soil quality and agrosystem.Therefore attempts to develop Integrated Nutrient Management package for rice i.e. application of farmyard manure combined with Azospirillum and Phosphobacteria in combination with recommended fertilizers gave 17.2 to 23.4% higher grain yield over application of nutrients through Inorganic fertilizer along with higher Benefit: Cost ratio of 2.80 to 3.25.(10) In case of these Biofertilizers the residual effect is more for chemical fertilizers on succeeding wheat crop. Similarly field trials of several other combinations of organisms could also be tested for several other cereals. Phosphate solubilizing bacteria like Pseudomonas striata(P-27) have a high P solubilzation activity and high anti fungal activity. Use of several such bioinoculantswith 11

combined attribute of fertilization and antipathogenic activity can provide long-lasting effective solutions for sustainable agriculture. Combined treatment with Phosphobacteria and mychorhizal fungi in several agriculturally important crops ex chillies, brinjal resulted in an increase in plant height, root length, biomass as well as total nitrogen and phosphorus content.(1,13) Combined inoculation of Azospirillum and VAM increased growth yield, nutrient uptake of plant than with no bacterium added extraneously. Co inoculation of Rhizobia and Phosphate solubilizing microorganisms is synergistic and results in better phosphate utilization and higher yield. Some of the Phosphate solubilizing microorganisms increase the uptake of nitrogen too.(1) Thus right kind of bacteria and fungi in root zone fix nitrogen, release minerals and provide protection against disease causing organisms too. Thus multiple inoculation has a very important role in the future of biofertilizers to develop Integrated Nutrient Management package for various crops thereby reducing our dependence on synthetic chemical fertilizers, decreasing the production cost and in long term benefits of soil and ecosystem for sustainable agriculture.

7)Present Status and Future Prospect for Emerging Biofertilizers In Global Market/India: One of the challenges of globalization and green revolution is not only to increase the yield but is also to improve the nutritional quality of product so that it matches global standards. The world over is Undergoing a shift from inorganic conventional farming towards organic ecofreindly farming methods. This not only requires the isolation of bioinoculantswith high potential for use as biofertilizersbut also several other factors right from proper application procedures to correct Marketing practices also being economically cheaper(2)

Proper Application Of biofertilizers:

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It has a very important role in deciding the optimum activity of the microorganisms. There are several ways of application i.e. liquid formulations, granular or powdery forms, carrier based preparation etc.(1,2) For example Liquid formulations of Azospirillum was more efficient than carrier based preparation .Similarly foliar spraying alone increased protein content by 14% whereas along with it the addition of bacterium as soil drench did not only improve any of the parameters significantly.(2) It also includes co inoculation techniques where 2 organisms for example Azospirillum, Azotobacter and Phosphate solubilizing bacteria increased the cost: benefit ratio also decreasing dosage of per bacterium. Such practices could play a ,major role in the future of these biological Based Products. Similarly VAMwhere exvivo and in vivo culture methods can be used to infect plants however various abiotic, biotic factor limit growth and development of VAM, thereby limiting its commercial application. Here In vivo culture methods act as an alternative to solve some of these problems. Hence in cases of VAMinvivio culture methods could prove more successful.(1,9,1213) As in the cases of cyanobacteria urea as a combined nitrogen source was proved to be far superior, also urea and sugarcane waste immobilized cyanobacterial Inoculation proved to be most efficient ways of practical application of biofertilizer should be found out to improve the yield. With Azolla biofertilizers which can be used as both a green manure bfore planting and intercropping with rice after planting .However latter practice has been found to be widely adaptable and more economical. Hence great emphasis should be on using correct biofertilizer application as this could result in an optimum activity and lower production cost and improve the yield by 10 to 15 % under field conditions but also reflects an increase in yield of succeeding crop in measurable quantities. Therefore following strategies have to be planned for increasing awareness and implementation of Biofertilizers and its long term benefits.

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Future strategies: Biofertilizers have been in use since 1960 but still Biological Based Product consumption has not picked up to expected levels. The major cause being too low acceptance by farmers. Quality and Pricing: Any new method to be adopted by farmers has to face initial resistance. To overcome this significant exhibitionism of Biofertilizers as a highly input extensive agricultural system need to be demonstrated. For this it is very important that the product entering the market is of standard quality and has passed through statutory laws or quality enforcement agencies as in developed countries.(2) Thus with proper Quality control of Biological Based Product will help in restoring the faith of farmers who will then be ready to try out these new techniques in their fields. Another important aspect for small marginal farmers in India is cost. There is remarkable discriminating variation in selling prices of various biofertilizers which need to be standardized that more farmers could be ready to experiment with it. Here the Government plays an important role. Role of Government in Promoting the use of Biofertilizers: Government has to ensure that the Biological Based Product entering the market has met with the standard quality laws set by them. Also the Government in the initial years of Biological Based Product promotion could highly subsidize the product which will help small marginal farmers especially to adopt it.(2,13) Concentrated efforts of the Government and Private firms to take into confidence local bodies will help to assess and adopt the technology. An proper marketing strategy depending on the Socioeconomic condition ,market heterogeneity and buying capacity of the consumer need to be planned to decide on various intermediaries for distribution and adoption of new technology by farms.(2) Later on awareness on the proper application procedures, limitations of product, and long term benefits of product needs to be created in farmers especially in interiors of the country. The Government could also encourage the private firms and research institutes to come together cooperate and promote training extension activity at farm level for farmers. 14

Poor microbial load, higher contamination and the use of improper strains resulted in mixed response of biofertilizers.Here the research institutes have a great responsibility towards ensuring the correct and the high quality product enters the market along with Government and thereby ensuring that substandard product do not enter the market. New practices take time to pick up success or failure of new entrants entering the market will depend on the proper marketing, branding, promotional policies of government for which study needs to be conducted at every level of production and consumption and factors affecting them.(2) Conclusion: Despite these factors Biofertilizers have made a rapid growth during last 15 years in country. National BiofertilizerDevelopment Centre has estimated the requirement of Biofertilizers to extent of 507032 MT of N2 mixed, 255340 MT of Phosphate mobilizing Bacteria. Though above figure represents theoretical potential of Biofertilizers it reflects the immense scope of Biological Based Product though far from reality.(2) Thus for this to turn into reality we could begin with the use of biofertilizer reduce the doses of chemical fertilizers, Thus we could ensure that optimum productivity and healthy returns under Integrated Nutrient Management system. This would help in cost benefit analysis help the farmers realize the worth ,potential, long term commercial benefits, economical aspects of using Biofertilizers an Biological Based Product which would then result in acceptance of this new improving tehnology,thereby would go on a long way in encouraging investment in Biological Based Product sector. It would then result in standard new Biological Based Product entering the market and thereby this ecofreindly renewable product would become an indispensable part of sustainable agriculture which will usher in another environmental eco friendly Green revolution.

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REFERENCES: 1)Ramarethinam,S;Murugesan,N.V;Rajalakshmi,N.(2005). “Effect of Liquid Formulation of Biofertilizer on the root Association of AM Fungi with Chilli roots”. Pestology. XXIX (4):1216. 2)Kakde,T.D;Wadaskar,R.M;Siddhabhatti,P.M;Nemade,P.WandTajne,V.S.(2005). “Marketing of Biological Based Products: Potential and Reality”. Pestology.XXIX (4):32-37. 3)Guler,Radhika;Gupta,R.P;Gosal,S.K;Pandher,M.S and Gosal,S.S.(2005) “In vitro and its mycorrhization of micro propagated sugarcane plants and its effect on yield”. Indian Journal of Microbiology.45 (1):71-73. 4) Annapurna, K.(2005) “Bradyrhizobium japonicum:survival and nodulation Of soybean as influenced by fungicide treatment”. Indian Journal of Microbiology.45 (4):305-307. 5) Shrivastav,S;Yadav,K.S and Kundu,B.S.(2004) “Prospects of using phosphate solubilizing Pseudomonas as Biofungicide”. Indian Journal of Microbiology.44:91-94. 6)Balachandar,D;Kumar,K;Arulmozhiselvan and Kannaiyan,S.(2005) “Influence Of Combined Nitrogen On Nitrogen transfer efficiency of immobilized cyanobacteria to rice seedlings”. Indian Journal Of Microbiology.45:257-260. 7) Vigneshwaran, N and Natarajan, T. (2003) “Nitrogen Fixation by phylloplane bacterium, Bacillus macerans in cotton “. Indian Journal of Microbiology.43:107-109. 8) Prasad, Rajendra; Kumar, Dinesh and Shivay, Y.S.(2006) “Strategies for sustained soil fertility”. Indian Farming, 4-8. 9) Mishra,Upasana;Singh,B.V and Wattal, Dolly(2005) “Biofertilizers and other Bionutrients for sustainavle rice production”. Indian Farming .11-14. 10) Ghosh,Amal.(2005) “Organic rice farming Technology development and its feasibility”, 16

Indian Farming. 4-7. 11) Prasad,Rajendra;Kumar,Dinesh and Shivay,Y.S.(2005)”Microbes and biological Nitrogen fixation, Indian Farming”,16-18.

12)Gupta,Pramila.(2006) “ Studies OF Efficacy Of Biofertilizers On the Yield Of Wheat(Triticum aestivum)and Mustard(Brassica juncea)” Journal of Microbial world,8:51-54 13)Deshmukh,A.M.(1998):Biofertilizersand Biopesticides,

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