This document presents information on biofertilizers and their roles in crop growth. It discusses various types of biofertilizers like Rhizobium, Azotobacter, Azolla, and their benefits such as nitrogen fixation, phosphate solubilization, and plant growth promotion. It provides details on the classification, methods of application including seed treatment and soil application. Pros of biofertilizers include improved soil health and fertility while constraints include technological, financial and awareness issues. The document aims to educate on the types and benefits of various biofertilizers.

1. Presented by:-
Prabin Dawadee
(CA-10536/17)
M.Sc.(Ag.) Agronomy
Credit Seminar on
BIOFERTILIZERS AND THEIR ROLES IN CROP
Name of Advisor:-
Prof. Karam Husain
(Department of Agronomy)

2. 1 BIOFERTILIZERS :- INTRODUCTION
2 BIOFERTILIZERS :-CLASSIFICATION
3 BIOFERTILIZERS :- METHOD OF APPLICATION
4 SOME BIOFERTILIZERS IN DETAIL
PROS & CONS5
CONTENTS

3. What is Biofertilizer ?
Bio - living and Fertilizer –things that nourished the crops
Biofertilizer is a substance or product which
contain selective strains of microorganisms which can
contribute nutrients to plants through microbial activity.
A product that contains living microorganisms,
which exert direct or indirect beneficial effects on plant
growth and crop yield through nutrients present in the
rhizosphere.

4.  Biofertilizers fix atmospheric Nitrogen and make it available
to the plant.
 They Solubilize the insoluble forms of Phosphates into
available forms.
 They Produce Hormones and Anti metabolites which
promotes plant growth.
 They Decompose Organic matter and help in Mineralization
in soil.
 When applied to seed or soil, bio-fertilizers improve the yields
by 10 to 40% without adversely affecting the soil and
environment.

5. 1. Fix atmospheric
nitrogen.
2. Solubilises
phosphorous.
3. Stimulate plant
growth.
4. Increases the
uptake of nutrient
5. Decompose
organic matter

6. Emerging multi-nutrient deficiencies
in soils
?
Mo Mo
B B B B
Mn Mn Mn Mn Mn
S S S S S
K K K K K K
Zn Zn Zn Zn Zn Zn
P P P P P P
Fe Fe Fe Fe Fe Fe Fe
N N N N N N N N
Year 1950 1960 1970 1980 1990 2000 2010 2025

7.  Bio-fertilizers offers eco-friendly technology
 They improve soil fertility and increase crop yield up to 10-40%.
 They improve pH and other properties of soil (Biological, Physical &
Chemical).
 They produces growth promoting substances (IAA, amino acids,
vitamins).
 It results in reduced cost of fertilization.

9. 38.64%
20.48%
15.56%
10.02%
5.93%
5.86% 2.28%
1.07%
0.16%
PSB
Rhizobium
Compost
Azotobacter
Green manure
BGA
Biogas slurry
Azospirillum
Vermicompost
Prospects of biofertilizers and organic manure utilization
(mean of 10 years)
Singh et al (2010)

10. 10
Sr.
no.
Name of the major
state
Production during the year (in tones)
2011-2012 2012-2013 2013-2014 2014-2015 2015-2016
1. Andhra Pradesh 1126 1335 2714 2943 3062
2. Gujarat 2037 3978 6411 6468 3963
3. Karnataka 5760 7683 9907 16485 23042
4. Kerala 904 1045 3520 4927 4926
5. Madhya Pradesh 2309 1408 4824 2757 2741
6. Maharashtra 8743 5897 6218 15172 7825
7. Punjab 692 2311 2124 562 2197
8. Tamil Nadu 3373 11575 14104 15384 23721
9. Uttar Pradesh 8695 1310 2682 4197 3053
10. Uttarakhand 263 2758 5493 2337 3549
11. West Bengal 603 1110 1682 2076 2826
Total production of India 40324 46836 65527 84751 88029
Production of Biofertilizer in India
Source: www.indiastat.com (2015-16)

12. Table 4 : Classification of Biofertilizers
Sr. No. Groups Examples
Nitrogen (N2) fixing Biofertilizers
1 Free-living Azotobacter, Clostridium, Nostoc
2 Symbiotic Rhizobium, Anabaena azolla
3 Associative Azospirillum
P Solubilizing Biofertilizers
1 Bacteria
Bacillus megaterium var. phosphaticum,
Bacillus circulans, Pseudomonas striata
2 Fungi Penicillium sp., Aspergillus awamori
P Mobilizing Biofertilizers
1 Endomycorrhiza Glomus sp., Gigaspora sp., Acaulospora sp. (AM)
2 Ectomycorrhiza Laccaria sp., Pisolithus sp., Boletus sp., Amanita sp.
3 Orchid mycorrhiza Rhizoctonia solani
Biofertilizers for Micro nutrients
1 Silicate and Zinc solubilizers Bacillus sp. , Pseudomonas
PGPR (Plant growth promoting rhizobacteria)
1 Psuedomonas Pseudomonas , Azatobacter, BGA

13. MAIN ROLES OF BIOFERTILIZERS
Make nutrients available.
 Make the root rhizosphere
livelier.
 Growth-promoting substances
are produced.
 More root proliferation.
 Better germination
Make the system more
sustainable.

14. Residual effect.
Improve the quality and
quantity of produce.
Improve the fertilizer use
efficiency.
Higher biotic and abiotic
stress tolerance.
Improve soil health.

15. Factors affecting Performance of Bio-fertilizers
Host plant Soil fertility Cropping practices
Environmental factors

16. BGA are photosynthetic, unicellular
Cyanobacteria
They also produce auxin, gibberellic acid and
vitamin B12
Also called paddy organisms.
Fix
atmospheric
nitrogen
Contribute
25- 30 kg N
/ha /seasonBGA
Increase
rice yield by
10-15 %
Secrete
Vitamins &
hormones

17. Fixes 40-60 kg N/ha in rice crop, supplement
nitrogen by 50 % to rice crop
Yield increase upto 25 %
Controls 50 % weeds in rice field.
Azolla pinnata: Important species, thrive 20-30 C
A. microphylla: It is heat tolerant but cold sensitive.
A. filiculoides: It is cold tolerant and heat sensitive.
Azolla fern is “Live Nitrogen Manufacturing Factory”
Azolla can accumulate 30 to 40 kg K2O ha-1 from irrigation water in
the paddy field.

18. RHIZOBIUM
 Establish efficient symbiotic association with
pulses, leguminous oil-seed and fodder crops.
 Can fix 25-50 kg N/ha.
 Also leave sizeable nitrogen in soil which can
meet a part of N requirement of succeeding crop
in rotation.
 Increases the yields of crop owing to inoculation
varies from 10 – 70 % over uninoculated control.
 Specific to each legumes, so should be used for
recommended leguminous crop only.

19.  Rhizobiun meliloti:- for Melilotus
(Sweet Clover), Medicago (Alfalfa),
Trigonella (Fenugreek)
 R. leguminosarum:- for Pes, Lentil,
Sweet Pea (Lathyrus sp.)
 R. japonicum:- for Soyabean,
Groundnut, Cowpea
 R. phaseoli:- for Phaseolus (bean)

20. Contribute
15-20 kg
N / ha
Enhance
Seed
germination
Produce
Antibiotics
Produce
PGPR
Stimulate
soil micro
organisms
Phosphate
solubilization
Yield
increase up
to 50 %
N2
Fixation
 Heterotrophic free-living and non-symbiotic N fixing
organism present in neutral and alkaline soils.
produce
antifungal and antibiotics
compounds against
Helminthosporium, fusarium
and Alternaria

21. Associative symbiotic nitrogen fixing bacteria
Increase mineral & water uptake, root development,
vegetative growth & crop yield.
Produce growth promoting substances like IAA, IBA, GA.
It is used for rice, sorghum, maize, castor, sunflower, wheat,
millets, corn etc.
Benefits:
Increased yield - 14 to 20 %
 Fix 20-25 kg N/ ha/season

22.  Aerobic nitrogen fixing bacteria which is capable for nitrogen fixing
in roots, stems and leaves of sugar plants.
 Associate with sugarcane, sweet potato plants.
 Longer Shelf-life (1 to 2 year)
 It can fixe 30 kg N/ha/year.
 Increase yield by 10-20 t/acre
 Increase Sugar content by 10-15 %
 It can also solubilize insoluble forms of P
Acetobacter

23. PLANT GROWTH PROMOTING
RHIZOBACTERIA
 Enhances plant growth and yield via various
plant growth promoting substances (IAA,
Gibberellic acid, etc. ).
 Improves seed germination, seedling growth
and yield of different crops .
 Protects the plant roots from the attack by
soil-borne pathogens.
 Reduce the harmful effect of heavy metals.

24.  PSMOs lower the pH and bring about the
dissolution of bound forms of phosphates.
 Produce plant growth promoting substances like
IAA, IBA & GA
 This helps in root formation, plant growth and
seed formation.
 Increase the yield up to 20%.
 Bacillus, Pseudomonas, Flavobacterium,
Micrococcus sp. are example of PSB (Phosphate
Solubilizing Bacteria) and Penicillium, Aspergillus
are example of PSF (Phosphate Solubilizing
Fungus)
Phosphate solubilizing Micro-Organisms

25.  Out of added phosphorus fertilizer only 10-20% is available
for the plants.
 PSMOs significantly helps in the release of this insoluble
inorganic phosphate and makes it available to the plants.
 Addition of these organisms saves almost 50% of phosphorus
fertilizers applied to the fields and optimizes the intake of
phosphorus by the plants.

26. AM Spores
 The term Mycorrhiza denotes “fungus roots” .
 Symbiotic association between host plants and
certain group of fungi at root system,
 Imparts tolerance to drought, transplantation
shock, salinity and plant pathogens.
 Increased plant uptake especially P, Ca, Zn, S.
 We can save 50% Phosphatic fertilizer without
affecting the yield .
 Glomus sp., Gigaspora sp., Laccaria sp., etc.
Phosphate absorbers)

27. Broadcasting soil mixed with
PSMOs
Root dip
fertigation
Application of PSMOs
Seed inoculation

28. K-Solubilizing Bacteria
Zinc solubilizers
Frateuria aurantia are capable of mobilizing mixture of K
into a usable form to the plants
The zinc can be solubilized by microorganisms viz.,
B. subtilis, Thiobacillus thioxidans and Saccharomyces sp.

29. Application of Bio-fertilizers
Seed treatment
or seed
inoculation
Seedling
root dip
Main field
application

30. 1. Seed treatment:
• 10-20g of Bio-fertilizers per kg seeds.
• Bio-fertilizer is mixed with water and adhesive
material.
• Dried for half an hour before sowing.
2. Seedling treatment:
• This is mainly done in transplanted crops.
• A slurry of bio-fertilizer is prepared.
• Seedlings are dipped in the slurry for about
15 minutes,
• Then transplanted to main field.
3. Soil application:
• 2 kg of bio-fertilizers are mixed with 40-50 kg
of decomposed FYM.
• Broadcast at the time of sowing/prior to sowing.
METHOD OF APPLICATION OF BIOFERTILIZER

31. Methods of application
(1) Seed treatment
Rate of application :
1. Nitrogenous bio-fertilizers
- 20 gm/kg seeds
2. Phosphatic bio-fertilizers
- 20 gm/kg seeds
3. Liquid bio-fertilizer
- 10 ml/kg seed

32. (2) seedling dip:
Add 50 ml Biofertilizer in 10 liters. of water
Mix thoroughly
Dip seedlings for 15-30 minutes
Transplant the seedling in field

33. (3) Soil treatment:
2 kg of biofertilizers are mixed
with 40-50 kg of compost or soil
and keep overnight.
(4) Sett treatment:
 50 ml of biofertilizers are mixed
in 10 liter of water
 Setts are dipped for 30 minute

34. Carrier based
 Cheaper
 Less investment
 Low shelf – life
 Temperature sensitive
 Contamination prone
 Less effective
Liquid based
 High cost
 Higher investment for
production unit
 Longer shelf – life
 Temperature tolerant
 Contamination free
 More effective

35. Liquid Biofertilizers Benefits
Longer shelf-life (12–24 months)
No loss of properties due to storage up to 45º C
(more temperature tolerant)
Greater potential to fight with native population
Better survival on seeds and soil
Very easy to use by the farmer
Traditionally liquid biofertilizers reduces the
chemical fertilisers usage by 15 – 40%.

36.  Bio-fertilizer packets need to be stored in cool and dry place.
 Keep away from direct sunlight and heat.
 Right combinations of bio-fertilizers have to be used.
 Some bio-fertilizer are crop specific, it should be use for the
specified crop only.
 Other chemicals should not be mixed with the bio-fertilizers.
 The packet has to be used before its expiry.
Precaution for using bio-fertilizer

37. PROS OF BIOFERTILIZER
 It improves the soil chemical and physical properties.
 Replace chemical fertilizers by 20-25%.
 Increase crop yield by 20-30%.
 B:C ratio of bio-fertilizers is always higher.
 Bio-fertilizers are eco-friendly.
 Cheap and have easy application methods.

38.  Stimulate plant growth.
 Reduce the pressure on non-renewable nutrient
sources/fertilizer
 Biofertilizers can act as a renewable supplement to chemical
fertilizers and organic manures.
 Restore natural soil fertility.
 Increase germination percentage.

39. Constraints in Bio-fertilizer Technology
Technological constraints
Infrastructural constraints
Financial constraints
Environmental constraints
Awareness on the technology
Marketing constraints

40. Technological constraints
Infrastructural constraints
Financial constraints
 Use of improper less efficient strains
 Unavailability of good quality carrier material
 Short shelf life of inoculant
 Crop specific
 There is no technology available for using as dry inoculum
 Lack of essential equipment
 Power supply
 Cold storage of inoculants.
 Non-availability of sufficient funds
 Less return by sale of products in smaller production units.

41. Marketing constraints
Awareness on the technology
Environmental constraints
 Seasonal demand for bio fertilizers
 Soil characteristics like salinity, acidity, drought, water logging, etc.
 Multiplication is a problem for BGA in non-traditional rice growing areas
due to high temperature (34 + 100 )
 Azolla cannot withstand desiccation (removal of moisture)and cannot be
used in upland rice.
 Unawareness on the benefits of the technology
 Problem in the adoption due to different methods of inoculation
 No immediate visual difference in the crop growth like that of inorganic
fertilizers.
 Non-availability of quality specifications and quick quality control methods
 Non availability of right inoculant at the right place in right time
 Lack of retain outlets or the market network for the producers due to short
shelf life

42. FUTURE NEEDS
 It is necessary to develop strains suitable for different crops
in different agro climatic conditions to fully harness the benefit
from the biofertilizers.
Poor quality of inoculants is a serious constraint for large scale
use. Hence, there is need to put greater effort in this direction
to achieve better quality of inoculants
The effect of biofertilizers on crop growth and yield is not as
striking as that of chemical fertilizers. However on long term
sustainability basis, biofertilizers has an important role to
play.

43. CONCLUSION
Bio-fertilizers being essential components of nutrient management can play
pivotal role in maintaining soil fertility but they cannot totally replace chemical
fertilizers . The changing scenario of agricultural practices and environmental
hazards associated with chemical fertilizers demand a more significant role of
biofertilizers in coming years.
From the foregoing discussion it can be concluded that biofertilizers
 Significantly reduce the chemical fertilizer requirements (especially N
and P)
 Improve soil fertility and productivities
 Ensure food and nutritional security