Biofertilizers are microbial preparations that enhance soil fertility by fixing nitrogen, solubilizing phosphorus, and promoting plant growth through their biological activities, serving as a sustainable alternative to chemical fertilizers. They can replace 25-30% of chemical fertilizers and improve soil health while also stimulating plant growth. The production and effectiveness of biofertilizers depend on factors such as microbial strain selection, quality control, and methods of application, with liquid formulations offering advantages over traditional carrier-based systems.

2. The term biofertilizer refers to preparation containing live
microbes which helps in enhancing the soil fertility either by
fixing atmospheric nitrogen, solubilization of phosphorus or
decomposing organic wastes or by augmenting plant growth by
producing growth hormones with their biological activities.
BiofertilizersBiofertilizers
Bacteria in root surfaceBacteria in root surface Bacteria in root surfaceBacteria in root surface Legume inoculationLegume inoculationRhizobium BacteriaRhizobium Bacteria

3. The role of biofertilizers assumes special
significance due to increased cost of
chemical fertilizers and their ill effects on
soil health
Legume root nodulesLegume root nodules
Rhizobium bacteria
inside nodule
Rhizobium bacteria
inside nodule
Biofertilizer concept goes back as early
as 300 BC when our ancestors realized
the importance of legume crops bearing
nodules.
The perspective of biofertilizer came into
existence through discovery of many
organisms capable of nitrogen fixation, P-
solubilization, P. mobilization, potash
solubilization and micronutrient
transformation in the soil.
Concept

4. Advantages of Biofertilizers
Renewable source of nutrients
Sustain soil health
Supplement chemical fertilizers.
Replace 25-30% chemical fertilizers
Increase the grain yields by 10-40%.
Decompose plant residues, and stabilize C:N ratio of soil
Improve texture, structure and water holding capacity of soil
No adverse effect on plant growth and soil fertility.
Stimulates plant growth by secreting growth hormones.
Secrete fungistatic and antibiotic like substances
Solubilize and mobilize nutrients
Eco-friendly, non-pollutants and cost effective method

5. Types of Biofertilizer Organisms
RHIZOBIUM
AZOSPIRILLUM
VA-MYCORRHIZA
BLUE GREEN ALGAE
AZOTOBACTER
PSB

6. Biofertilizers
covered under FCO
Other Biofertilizers not covered
in FCO
Rhizobium
Azotobacter
Azospirillum
PSB
Mycorrhiza
Acetobacter
Fraturia aurantia
Pseudomonas as PGPR
Mixed cultures
Effective microorganisms

7. AZOSPIRILLUM BIO-FERTILIZER

8. AZOTOBACTER BIO-FERTILIZER

9. PHOSPHATE SOLUBILIZING
BIO-FERTILIZER

15. Biofertilizer
Carrier based Liquid based
Advantages
•Cheap
•Easier to produce
•Less investment
Disadvantages
•Low shelf life
•Temperature sensitive
•Contamination prone
•Low cell count
•Less effective
•Automation difficult
Advantages
•Longer shelf life
•Easier to produce
•Temperature tolerant
•High cell count
•Contamination free
•More effective
Disadvantages
•High cost
•Higher investment for
production unit

16. • The production technology of bacterial biofertilizers
can be summarized in the following steps
 Selection of strain
 Preparation of Broth culture
 Preparation and sterilization of liquid
medium in conical flasks
 Preparation of primary inoculum (Mother
culture)
 Quality test of primary inoculum
 Inoculation of broth with primary inoculum
(Mother inoculum)
 Shaking with incubation
 Quality test of broth culture

17.  Blending of broth culture with carrier and curing
 Blending of broth culture with carrier material
 Curing of blended formulation at 28-30ºC
 Packing and storage of inoculants
 Packing of final product
 Storage at low temperature
 Sampling and quality test of final product
 pH
 Moisture percentage
 Total viable cell count per gram of carrier
 Percentage of contamination

21. Rhizobium
Azotobacter
Azospirillum
PSB

22.  N-Biofertilizers can provide 25-30% of chemical fertilizer
equivalent N
 PSB biofertilizer can provide 12-20 kg P2O5/ha/season
 Mycorrhiza can provide adequate, P, other micro
nutrients and help in increased water absorption
 Mixed biofertilizer give better impact
 Keep soils biologically active
 Help in soil health maintenance

23. Biofertilizer/ crop Quantity
required
lit/ha
Cost of
application
(Rs/ha)
Amount of nutrient
mobilized kg/ha
Rhizobium in legumes 0.2-1.0 lit 40 - 200 25 – 35 kg N
Azotobacter/
Azospirillum in non-
legumes
0.5 – 2.0 lit 80 - 400 20 - 25 kg N
Azoto+Azosp+PSB 0.5 – 2.0 lit 80 - 400 20 kg N + 12 kg P
Mixed inoculants 0.5 – 2.0 lit 80 - 400 25 kg N +15 kg P
Mycorrhiza 2.00 – 5.00
kg
200-500 20-25 kg P +
micronutrients+
moisture

24. (i) Base Carrier based* in form of moist/dry
powder or granules, or liquid based
(ii) Viable cell count CFU minimum 5x107
cell/g of powder,
granules or carrier material or 1x108
cell/ml of liquid.
(iii) Contamination level No contamination at 105
dilution
(iv) pH 6.5-7.5
(v) Particles size in case of carrier
based material.
All material shall pass through 0.15-
0.212mm IS sieve
(vi) Moisture percent by weight,
maximum in case of carrier
based.
30-40%

25. S.
No.
Parameter Specification requirement
(vii) Efficiency character
a.For Rhizobium
b.For Azotobacter
c.For Azospirillum
a.For PSB
Should show effective nodulation on all the species
listed on the packet.
The strain should be capable of fixing at least 10 mg
of nitrogen per g of sucrose consumed
Formation of white pellicle in semisolid N-free
bromothymol blue media
The strain should have phosphate solubilizing
capacity in the range of minimum 30%, when tested
spectrophotometrically. In terms of zone formation,
minimum 5mm solubilization zone in prescribed
media having at least 3mm thickness
Sources : NCOF (2011)Sources : NCOF (2011)

26. i. Form/base Fine Powder/ tablets/ granules/ root
biomass mixed with growing
substrate
ii. Particle size for carrier
based powder formulations
90% should pass through 250
micron IS sieve (60 BSS)
iii. Moisture content percent
maximum
8 -12
iv. pH 6.0 to 7.5
v. Total viable propagules/ gm
of product, minimum
100 /gm of finished product
V. Infectivity potential 80 infection points in test roots/gm
of mycorrhizal inoculum used

27. Above Six states account for 86% of total
Biofertilizer production in the country
Sources : NCOF (2011)Sources : NCOF (2011)

28. Poor Acceptability among farmers may be attributed to:
1. Inconsistent responses
2. Poor quality of carrier based products
3. Sensitivity to temperature and short shelf
life
4. Non-compatibility with chemical seed
dressers/ fertilizers
5. Poor organic carbon in soils
6. Dependence for supply on Government
system

29. Poor quality unsterile carrier is biggest
constraint
 Replace lignite/ charcoal with other carriers having high
moisture potential
 Such as Exfoliated vermiculite, ppt grade silica, Quartz or inert
mineral powder enriched with synthetic water holding gels.
 All carriers must be sterilized and
 Product handling process must be automatic
 Product must be free from contamination

30. Efforts needed to replace existing carrier based
system to liquid system as it is:
a. Easier to produce
b. 100% automation possible
c. Product can be 100% sterile
d. Offer higher shelf life, higher cell count
e. Temperature tolerant
f. Easy to apply through mechanical means
Sources : NCOF (2011)Sources : NCOF (2011)

31. Efficiency of biofertilizers depend on organic carbon in soil
a. Use both as seed treatment and soil
treatment
b. For soil treatment mix with compost
c. PSB to be used as soil treatment with
compost
d. Mixed application of biofertilizers to be
promoted

32.  Use of multiple inoculants have proved
beneficial over single inoculants
 Many producers have launched mixed liquid
inoculants having Azotobacter, Azospirillum
and PSB.
 States can promote use of mixed inoculants

33. Use Biofertilizers
For Healthy and living soil