Biofertilizers are living organisms that enhance plant nutrient availability, serving as an eco-friendly alternative to chemical fertilizers. They include various types such as rhizobium, azotobactor, and blue-green algae, each with distinct roles in nitrogen fixation and nutrient solubilization. The document also outlines application methods, storage precautions, and the importance of integrating biofertilizers with conventional fertilizers for optimal agricultural benefits.

1. Biofertilizers
seema prajapat

2. Biofertilizers
Biofertilizers refers to living organisms which augement plant
nutrient supplies in one way or the other.
They are environment friendly and cost effective supplement
to chemical fertilizers and organic manures.They play a
significant role in improving nutrient avalibility to crop plants.

3. Classification of biofertilizers:
● Rhizobium
● Azotobactor
● Azospirillum
● Frankia
● Azolla
● Blue green algae(BGA)
● Vasicular arbuscular mycorrhiza(VAM).

4. Biofertilizers
Nitrogen fixing
Phosphate
solubilizing
Organic matter
decomposer
Symbiotic Non-symbiotic
Phosohate
solubilizer
Phosphate
mobilizers
Celluloytic Lignolytic
Tricoderma
Cytophaga
Agaricus
Fomes
Bacillus
Aspergillus
Penicilium
VAM
Glomus
Azotobactor
Azospirllium
Clostridium
Anabaena
Cynobactria
Beijerinckia
Nodule
s
Non-
nodule
s
StemRoot
Sesbania
Legumes-
Rhizobium
Bradyrhizobium
Non-legumes
Frankia

5. Rhizobium:
● Among biofertilizers,Rhizobium inoculants are of greatest
importance because of their ability to fix atmosphere N2 in
association with certain legumes.
● Some species- Rhizobium trifoli - clover.
Rhizobium meliloti -medicago.
Rhizobium species.

6. Azotobactor:
● Azotobactor fixes atmospheric N2 non-symbiotically,an
aerobic,chemo-heterotropic and free living organism.
● They are very effective in enhancing yield of crops like
wheat,rice,sorgham etc. and vegetables crops like
onion,brinjal,tomato,cabbage etc.

7. Azospirillum:
● Azospirillum is a chemo-heterotrophic bacteria associated
to live within the roots of sorgham,pearl millet,rice,
maize,wheat and sugarcane crops.
● They can fix atmospheric N2 to the extent of about 15-
30kgN/hac.

8. Frankia:
● It shows symbiotic association with certain non-
legumes,mainly with trees and shrubs.
● It has modest agricultural importance because its potential
in fixing N from atmosphere is not widely known.
● However,its potential could be haressed in agroforestry.

9. Azolla:
● Azolla is known as free floating water fern.
● Azolla fixes atmospheric N2 in symbiotic association with
blue green algae(Anabaena azollae) in rice fields.
● Azolla supplies N to rice after its decomposition just like
any other organic matter.
● It takes about 8-10 days to decompose and release about
67 percentage of its N within 35 days.

10. Blue green algae:
● Blue green algae are also known as cynobacteria.
● The first account of agronomic potential of BGA in rice was
presented by P.K.De, who attributed the natural fertility of
tropical rice field to these N2 fixing organisms.
● The N2 fixing potential of BGA can be estimated by
evaluating its biomass,N-content and N2 fixing activity.
● BGA can contribute about 20-30 kg N/ha.

11. Phosphate solubilizing microorganism(PSM
● A group of heterotrophic microorganisms possesses the
ability to solubilize inorganic P from insoluble sources to
soluble forms i.e.-Bacillus magatherium phosphobactrium
b.polymyxa,penicilium etc.
● Acid phosphates play a major role in the mineralizationof
organic P in soil.

12. Vesicular-arbuscular mycorrhiza(VAM):
● The symbiotic association between plant roots and fungi is
termed as mycorrhizal association,which is known to
improve the growth and yield of crops in nutrient-deficient
conditions(increase uptake of K,S,Cu and Zn).
● VAM infections have shown benificial effects are
sorgham,barley,wheat,rice(upland),tobacco,cotton,soyaben
,graps,citrus,apple etc.

13. Organic matter decomposer:
● Composting is a key technology to use a wide varity of
organic wastes,including crop residues and rural and urban
wastes.
● The effecient cellulolytic and lignolytic cultures used for
rapid decomposition are Tricoderma viride,Trichurus
spiralis,Aspergillus niger etc.

14. Plant growth promoting rhizobacteria(PGPR)
● Plant growth promoting rhizobacteria are also known as
rhizosphere bacteria that exert benificial effect on plant
growth,belong to several
genera,viz.,Agrobacterium,Bacillus,Pseudomonas,Rhizob
ium,Azotobactor,Zantomonas etc.
● Siderophores are Fe-chelating compound produced by
certain soil microorganisms.

15. Methods of application of biofertilizers

16. Seed treatment:
● For treating seeds,200g of biofertilizer is suspended in 300-
400 mL of water and mixed gently with the seeds(10kg)
using an adhesive like gum acacia,jaggery solution etc.
● Care should be taken to avoid any damage to seed coat.
● The seeds are then spread on a clean sheet/cloth under
shade to dry and used immediatly for sowing.

17. Seedling root tip:
● For rice crop,a bed is made in the field and filled with water.
● Recommended biofertilizers are mixed in this water and
the roots of seedling are dipped for 8-10 h and
transplanted.

18. Soil tratment:
● Four kilogram each of the recommended biofertilizers is
mixed in 200kg of compost and kept overnight.
● The mixture is incorporated in the soil at the time of sowing
or planting.

19. Precautions for using biofertilizers:
● Biofertilizer packets need to be stored in a cool and dry
place,away from direct sunlight and heat.
● The packet has to be used before its expiry date,only for
the specific crop and by the specified crop and by the
recommended method of application.
● While purchasing one should ensure that each packet is
provided with necessary information like name of the
product,name of the crop,date and batch number etc.

20. ● It is important to use biofertilizers along with chemical
fertilizers and organic manures.
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