INTERNATIONAL JOURNAL OF BIOPHARMACEUTICAL SCIENCES (ISSN:2517-7338)

Biofertilizers are constituents of microbial cells that colonizes rhizosphere of the plants to improve nutrient uptake by increasing the rate of mineralization of insoluble nutrients in the soil through numerous natural process such as nitrogen fixation, phosphorous fixation etc.

Arbuscular Mycorrhiza; Bacillus subtilis; Bacilluscirculans; Azolla; Azospirillum

Biofertilizer is a biotic constituent of specific microbial cells, which when applied, stimulates plant growth by accelerating the rate of nutrient release through nitrogen fixation, phosphorus cycle, etc. [1]. In vitro cultures of specific microbes are selected for the preparation of biofertilizers to fulfill the specific nutrient requirements of different plants [2]. Biofertilizer is categorized into different given below.

a. Nitrogen fixing

• Free-living: Clostridium, Azotobacter, Nostoc, Anabaena, etc. [3
• Symbiotic: Rhizobium, Azalea, Anabaena, etc. [4]
• Associative Symbiotic: Azospirillum [5]

b. Phosphorous solubilizing

• Bacteria: Bacillus subtilis, Pseudomonas striata, Bacillus circulans, etc. [6]
• Fungi: Aspergillus awamori, Penicillium sp, etc [7]

c. Phosphorous mobilizes

• Arbuscularmycorrhiza: Glomus sp, Acaulospora sp, Gigaspora sp & Sclerocystis sp [8]
• Ectomycorrhiza: Laccaria, Boletus sp, Amanita sp [9]
• Arcade mycorrhizae: Pezizellaericae [10]
• Orchid mycorrhiza: Rhizoctonia solani [11]

 d. Biofertilizers for Micronutrients

• Silicate and Zinc solubilizers: Bacillus sp [12]

e. Plant Growth Promoting Rhizobacteria

• Pseudomonas: Pseudomonas fluorescens [13]
  

Rhizobium: Rhizobium is a nitrogen fixing bacteria that colonize the root nodules of legume plants and is an effective biofertilizers [14]. They are referred as cross inoculation group for being specific to form root nodules in legume plants and has seven genera [15,16]. For all legume plants it is applied as seed inoculant [17].

Azotobacter: Another nitrogen fixing bacteria inoculant that produces ample slime which aids in soil aeration. e. g. A. Chroococcum

[18]. Azospirillum: Nitrogen fixing bacteria that colonize the non-leguminous graminaceous plants rhizosphere and intercellular spaces of root cortex e. g. Azospirillum lipoferum, A. Brasilense, A. Amazonense [19]. Besides these have the ability to reduce nitrate, denitrify, etc. [20]. Azospirillum is inoculated through seed, seedling root dip and soil application methods [21].

Cyanobacteria: Free-living/symbiotic cyanobacteria is used as a biofertilizers for rice [22].

Azolla: Azolla is a free-floating water fern that fixes atmospheric nitrogen in association with cyanobacteria [23]. it is used as biofertilizer for wetland rice [24].

Phosphate solubilizing microorganism: Microorganisms such as Pseudomonasstriata, Bacilluspolymyxa, Penicillium, Aspergillus, etc. secretes organic acids that cause dissolution of bound phosphates in soil [25].

Arbuscular Mycorrhiza: Intracellular obligate fungal endosymbionts that possesses vesicles for storage of nutrients and arbuscles for directing phosphorus, zinc and sulfur into the root system [26].

Silicate solubilizing bacteria: Some microbes are capable of dissolution silicates by secretion of organic acids like citric, oxalic acid, etc. [27]. e. g. Bacillus sp. [28].

Plant Growth Promoting Rhizobacteria: Such inoculants are either bioprotectants (suppresses plant disease), biofertilizers (improves nutrient acquisition) or biostimulants (phytohormone production) [29]. e. g. Pseudomonas and Bacillus species [30].

• Long shelf life.
• No contamination.
• No loss of activity.
• Easy documentation.
• Cost effective.
• Quality control protocols are easy and quick.
• Better performance. • Easy to use.
• Less dosage required.
• High marketable profit.
• High distribution potential.
• High enzymatic activity [31-36].
  

• Fixing nutrient availability in soil.
• Improves soil fertility.
• Readily converts complex organic compounds into simple soluble forms.
• Accelerates mineral uptake by plants.
• Increases crop yield.
• Stimulates plant growth.
• Provide resistance against drought and soil-borne diseases
• Cost-effective [37-40].

Uses of biofertilizers

• Treatment of seed.
• Root dipping of seedlings.
• Main field uses [41].

Though this technology is cost effective, environmental friendly, but still there are numerous limitations that restrict its implementation [42].

Technical limitations

• Use of less effective strains.
• Absence of competent technical staff.
• Synthesis of poor quality inoculants.
• Short shelf life of inoculants [43-45].

Infrastructural limitations

• Deficiency of appropriate production facilities.
• Absence of crucial production equipments.
• Availability of space for production or storage, etc.
• Lack of cold storage facility for inoculants [46-48].
• Insufficient funds.
• Low profit generation in smaller scale units [49].

Conservation limitations

• Cyclical demands for biofertilizers.
• Instantaneous harvesting.
• Short duration of sowing/planting.
• Soil characteristics [50-53].

Human resources and quality limitations

• Lack of technical expertise.
• Lack of appropriate training.
• Manufacturer ignorance regarding product quality.
• Unapproachability of quality management and control methods
• Lack of strict regulations [54-57].
  

Awareness limitations

• Lack of knowledge about the technology assistances.
• Reluctance to practice.
• No apparent change in the growth of crop.
• Lack of knowledge of the environmental impacts of inorganic fertilizer [57-59].

Marketing limitations

• Unavailability of right inoculant.
• Lack of preserving channels or markets for the producers [60,61].

This biofertilizers proves to be an effective way of supplementing the plants with soluble essential nutrients for the sake of good growth and commercial benefit.

1. Rai M. (Ed.) Handbook of microbial biofertilizers. CRC Press.2006.
2. Dahm H, Wrotniak-Drzewiecka, Pauter W, Szajdak LW, Karabanow AK, et al. Microbial biofertilizers Physical, chemical and biological processes in soils. 2010;537-547.
3. Glick BR. The enhancement of plant growth by free-livingbacteria. Can J Microbiol. 1995; 41(2):109-117.
4. Cocking EC. Endophytic colonization of plant roots by nitrogenfixing bacteria. Plant and soil. 2003 May;252(1):169-175.
5. Singh M, Dotaniya ML, Mishra A, Dotaniya CK, Regar KL, et al.Role of biofertilizers in conservation agriculture. ConservationAgriculture. 2016 Nov;113-134.
6. Rodrı́guez H, Fraga R. Phosphate solubilizing bacteria and theirrole in plant growth promotion. Biotechnol Adv. 1999 Oct;17(4-5):319-339.
7. Ogbo FC. Conversion of cassava wastes for biofertilizerproduction using phosphate solubilizing fungi. BioresourTechnol. 2010 Jun;101(11):4120-4124.
8. Singh S, Kapoor KK. Inoculation with phosphate-solubilizingmicroorganisms and a vesicular-arbuscular mycorrhizal fungusimproves dry matter yield and nutrient uptake by wheat grownin a sandy soil. Biology and Fertility of Soils. 1999 Jan;28(2):139-144.
9. Landeweert R, Hoffland E, Finlay RD, Kuyper TW, van BreemenN. Linking plants to rocks: ectomycorrhizal fungi mobilizenutrients from minerals. Trends Ecol Evol. 2001 May;16(5):248-254.
10. Read DJ. The structure and function of the ericoid mycorrhizalroot. Annals of Botany. 1996 April;77(4):365-374.
11. Gianinazzi-Pearson V, Gianinazzi S. Proteins and protein activitiesin endomycorrhizal symbioses. Mycorrhiza 1995;251-272.
12. Raj SA. Solubilization of silicate and concurrent release of phosphorus and potassium in rice ecosystem. Biofertilizers Technology. 2010;372.
13. Lugtenberg B, Kamilova F. Plant-growth-promoting rhizobacteria.Annual Annu Rev Microbiol. 2009;63:541-556.
14. Saxena AK, Tilak, KVB R. Potentials and prospects of Rhizobium biofertilizer. Agromicrobes. (Jha MN, Sriram S, Venkataraman GS, Sharma SG, eds). Todays and Tomorrow’s Printers and Publishers, New Delhi. 1999;51-78.
15. Boonkerd N, Singleton P. Production of rhizobium biofertilizer. Biotechnology of Biofertilizers, Narosa Publishing House, New Delhi, 2002:122-128.
16. Totey NG, Khatri PK, Shadangi DK, Bagde M, Pathak HD. Effect of (Rhizobium) Biofertilizer on the growth of seedlings and germination of seed of D. sissoo. Indian journal of forestry. 1997;20(1):54-56.
17. Tilak KVBR, Jauhri KS, Saxena AK. Rhizobium biofertilizer technology for legumes. IARI, New Delhi. 1992;32.
18. Pandey A, Kumar S. Potential of Azotobacters and Azospirilla as Biofertilizers for Upland Agriculture-A Review. Journal of Scientific & Industrial Research. 1989;48(3):134-144.
19. Balasubramaian A, Kumar K. Performance of Azospirillumbiofertilizer in irrigated and rainfed upland rice. International Rice Researh Newsletter (Philippines).1987.
20. Kumar K, Balasubramanian B. Field response of rice to Azospirillum biofertilizer. Current Research. 1986:15(7):4-7.
21. Kumar K, Balasubramanian A. Evaluation of two methods of Azospirillumbiofertilizer application in rice. Mysore Journal of Agricultural Sciences. 1989;23:1-5.
22. Kaushik BD. Developments in cyanobacterialbiofertilizer. In ProcIndian Nat Sci Acad. 2014 Jun;80(2):379-388.
23. Wagner GM. Azolla: a review of its biology and utilization. TheBotanical Review. 1997;63(1):1-26.
24. Kannaiyan S. Azollabiofertilizer for rice. In INSFFER Training Seminar. Int Rice Res Inst Manila. 1981;11.
25. Khan MS, Zaidi A, Wani PA. Role of phosphate-solubilizingmicroorganisms in sustainable agriculture-a review. Agronomyfor sustainable development. 2007 Mar;27(1):29-43.
26. Mosse B. Plant growth responses to vesicular‐arbuscularmycorrhiza. New Phytologist. 1973;72(1):127-136.
27. Ahmad M, Nadeem SM, Naveed M, Zahir ZA. Potassiumsolubilizing bacteria and their application in agriculture.Potassium solubilizing microorganisms for sustainableagriculture. 2016;293-313.
28. Zaidi A, Khan M, Ahemad M, Oves M. Plant growthpromotion by phosphate solubilizing bacteria. ActamicrobiologicaetimmunologicaHungarica. 2009;56(3):263-284.
29. Van Loon LC. Plant responses to plant growth-promotingrhizobacteria. European Journal of Plant Pathology.2007(119):243-254.
30. Ahemad M, Kibret M. Mechanisms and applications of plantgrowth promoting rhizobacteria: current perspective. Journal ofKing Saud University-Science. 2014;26(1):1-20.
31. Maheswari UN, Elakkiya T. Effect of liquid biofertilizers on growthand yield of Vignamungo L. Int J PharmSci Rev Res. 2014;29:42-45.
32.  Sahu PK, Brahmaprakash GP. Formulations of biofertilizers–approaches and advances. Microbial inoculants in sustainableagricultural productivity. 2016;179-198.
33. Brahmaprakash GP, Sahu PK. Biofertilizers for sustainability.Journal of the Indian Institute of Science. 2012;92(1), 37-62.
34. Altuhaish A, Altuhaish A, Tjahjoleksono A. Biofertilizer effects incombination with different drying system and storage period ongrowth and production of tomato plant under field conditions.Emirates Journal of food and agriculture. 2014 Jun;26(8):716-722.
35. Díaz-Zorita M, Fernández-Canigia MV. Field performance of aliquid formulation of Azospirillumbrasilense on dryland wheatproductivity. European journal of soil biology. 2009 Feb;45(1):3-11.
36. Phua CKH, Khairuddin AR. Multifunctional liquid bio fertilizeras an innovative agronomic input for modern agriculture.2010;43(26).
37. Magarvadiya DK, Patel VT. Knowledge and Attitude of Farmers Regarding Biofertilizers. Guj J Extn Edu. 2014;25:149-151.
38. Uribe D, Sánchez-Nieves J, Vanegas J. Role of MicrobialBiofertilizers in the Development of a Sustainable Agriculturein the Tropics. Soil biology and agriculture in the tropics. 2010Feb;21:235-250.
39. Gaur V. Biofertilizer–necessity for sustainability. J Adv Dev2010;1:7-8.
40. Aggani SL. Development of bio-fertilizers and its future perspective. Sch Acad J Pharm. 2013;2(4):327-332.
41. Malusá E, Sas-Paszt L, Ciesielska J. Technologies for beneficialmicroorganisms inocula used as biofertilizers. Scientific WorldJournal. 2012;2012:491206.
42. Mulongoy K, Gianinazzi S, Roger PA, Dommergues Y. Biofertilizers: agronomic and environmental impacts and economics. Biotechnology: Economic and social aspects: issues for developing countries. 1992;55-69.
43. Carvajal-Muñoz JS, Carmona-Garcia CE. Benefits and limitations of biofertilization in agricultural practices. Livestock Research for Rural Development. 2012;24(3):1-8.
44. Tarus D, Mensah A, Masso C, Watiti JF, Nang’ayo F. Biofertilizer Regulation in Ghana: Capacity Limitations to Effective Enforcement. Compro II Policy. 2015 Jul;5:1-2.
45. Herrmann L, Lesueur D. Challenges of formulation and quality of biofertilizers for successful inoculation. Appl Microbiol Biotechnol. 2013 Oct;97(20):8859-8873.
46. Naveed M, Mehboob I, Shaker MA, Hussain MB, Farooq M. Biofertilizers in Pakistan: initiatives and limitations. Int J AgricBiol. 2015;17(3): 411-420.
47. Roy MD, Sarker K, Ghosh PP, Dutta S. Use of microbial in oculantsin resilient agriculture: prospects and limitations. SATSA Mukhaptra Annual Technical Issue. 2015;19:88-96.4
48. Borkar SG. Microbes as Bio-fertilizers and their Production Technology. WPI Publishing. 2015 Jun;218:e1.
49. Roger PA. Rice field cyanobacteria: ecology, contribution to soil fertility and practical utilisation. Science Publ. 2001 Jan;199-226.
50. Sophiya L, Oinam G, Leingaklemba MK, Singh HB, Tiwari ON, etal. Distribution, Preservation and Maintenance of Cyanobacterial Diversity and their Application as Biofertilizer. Algal Biology and Biotechnology. I. K. International Publishing. 2009;8:109.
51. Dinesh R, Srinivasan V, Hamza S, Manjusha A. Short-termincorporation of organic manures and biofertilizers influencesbiochemical and microbial characteristics of soils under anannual crop [Turmeric (Curcuma longa L.)]. Bioresour Technol.2010 Jun;101(12):4697-4702.
52. Shaikh ANK. Potential of BiofertilizersOver Chemical Fertilizers.National Conference on Emerging Trends in Science andTechnology.
53. Parmar SN. Comprehensive Awareness Amomg The Farmers About The Application Of Bio-Fertilizers In Anand District. 2014;04-1890-2012.
54. Thakur N. Organic Farming, Food Quality, and Human Health: A Trisection of Sustainability and a Move from Pesticides to Ecofriendly Biofertilizers. Probiotics in Agroecosystem. 2017;491-515.
55. Ju I, Wj B, Sila Md, Onyimba IA, Egbere OJ. A review: Biofertilizer-Akey player in enhancing soil fertility and crop productivity. JMicrobiol Biotechnol Rep. 2018;2(1):22-28.
56.  Bagyaraj DJ, Aparna J. Scope of nutrient management through mycorrhizal and other biofertilizers technology. Biotechnology, emerging trends. Scientific Publishers. 2009;1-17.
57. Tarus D, Kabole M, Masso C, Watiti J, Nang’ayo F. Bio-fertilizerRegulation in Kenya: Legal Frameworks, Institutional andCapacity Limitations. 2015 Jul;4.
58.  Thombre RR, Ingle SP. A Study Of Farmers Awareness Towards Biofertilizers Consumption In Aurangabad District. 2016;5(8).
59. Reddy KG, Madhavi GB, Reddy ASR, Yellareddygari SK, Reddy MS. Current status of biofertilizers development, farmers acceptance, utilization and future perspective in Andhra Pradesh, India. Plant Growth-Promoting Rhizobacteria (Pgpr) For Sustainable Agriculture. 2011 Aug;2011:373-382.
60.  Rao NS, Mishra U. Strategic Marketing of Biofertilisers. Krushak. 2012.
61. Sale D. Marketing Of Plantozyme Liquid Biofertilizer In Pune District (Doctoral Dissertation, Mpkv, University Library). 2000Jul;9816.