Biofertilizers: types, production
and application
By- Dr. Ekta Khare
, Biofertilizers
• Biofertilizers is a substance which contains living
microorganisms, which when applied to seed, plant
surface, or soil, colonizes the rhizosphere or interior of the
plant and promotes growth by increasing the supply or
availability of primary nutrients to the host plant.
OR
• Biofertilizers are carrier-based microbial inoculants
containing sufficient cells of efficient strains of specific
microoranisms, that help in enhancing the soil fertility by
fixing atmospheric nitrogen, solubilization/ mineralization
of phosphorus or decomposing organic wastes, by
augmenting plant growth promoting substances with their
biological activities.
, Characteristics of Biofertilizers
• They are reasonable and nature friendly fertilizers which
contain microbial inoculants of algae, fungi and bacteria
either alone or in combination.
• Highly suggested for improving soil fertility and health.
• They are easily applicable and do not require any extra
proficiency.
• They require in less quantity in comparison to synthetic
fertilizers.
• They help in enrichment of soil through micro- flora build up.
, Types of biofertilizers (on the bases of
nature and function)
1. Nitrogen fixing: Nitrogen is most abundant and ubiquitous in the air, yet becomes
a limiting nutrient due to difficulty of its fixation and uptake by the plants. However,
certain microorganisms, some of which can form various associations with plants as
well, are capable of considerable nitrogen fixation. These microbes can be:
– Bacteria
• Free living: Free-living in the soil eg. Azotobacter
• Associative: Living in rhizosphere (associative/associated) without
endophytic symbioses. Eg. Azospirillum
• Symbiotic: Having symbiotic and other endophytic associations with plants.
Eg. Rhizobia, Frankia
– Blue grean algae (Cyanobacteria): have been reported to be helpful in enhancing
rice-field fertility for the cultivation of rice in many parts of the world. BGA can
further provide natural growth hormones, 172 proteins, vitamins, and minerals
to the soil. Eg. Anabaena, Nostoc, Tolypothrix, Cylindrospermum etc.
– Azolla: is a floating pteridophyte, which contains as endosymbiont the nitrogen-
fixing cyanobacterium Anabaena azollae. Azolla is either incorporated into the
soil before rice transplanting or grown as a dual crop along with rice.
, 2. Phosphate solubilizing:
The phosphorus-solubilizing bacteria (PSB) can increase phosphorus availability to
plants by dissolution of bound phosphates in soil by secreting organic acids
characterized by lower pH in their vicinity. Eg. Bacillus spp., Paenibacillus spp.,
Pseudomonas spp. etc.
3. Phosphate mobilizing:
The mycorrhizal fungi form obligate or facultative functional mutualistic symbioses
with more than 80% of all land plants, in which the fungus is dependent on host
for photosynthates and energy and in return provides a plethora of benefits to its
host. The mycelium of the fungus extends from host plant root surfaces into soil,
thereby increasing the surface area for more efficient nutrient access and
acquisition for the plant, especially from insoluble phosphorus sources and others
like calcium, copper, zinc, etc, eg. ectomycorrhiza (Laccaria spp., Pisolithus spp.,
Boletus spp., Amanita spp.), endomycorrhiza (eg. arbuscular mycorrhiza- Glomus
sp., Gigaspora sp., Acaulospora sp., Scutellospora sp., and Sclerocystis sp.)
and application
By- Dr. Ekta Khare
, Biofertilizers
• Biofertilizers is a substance which contains living
microorganisms, which when applied to seed, plant
surface, or soil, colonizes the rhizosphere or interior of the
plant and promotes growth by increasing the supply or
availability of primary nutrients to the host plant.
OR
• Biofertilizers are carrier-based microbial inoculants
containing sufficient cells of efficient strains of specific
microoranisms, that help in enhancing the soil fertility by
fixing atmospheric nitrogen, solubilization/ mineralization
of phosphorus or decomposing organic wastes, by
augmenting plant growth promoting substances with their
biological activities.
, Characteristics of Biofertilizers
• They are reasonable and nature friendly fertilizers which
contain microbial inoculants of algae, fungi and bacteria
either alone or in combination.
• Highly suggested for improving soil fertility and health.
• They are easily applicable and do not require any extra
proficiency.
• They require in less quantity in comparison to synthetic
fertilizers.
• They help in enrichment of soil through micro- flora build up.
, Types of biofertilizers (on the bases of
nature and function)
1. Nitrogen fixing: Nitrogen is most abundant and ubiquitous in the air, yet becomes
a limiting nutrient due to difficulty of its fixation and uptake by the plants. However,
certain microorganisms, some of which can form various associations with plants as
well, are capable of considerable nitrogen fixation. These microbes can be:
– Bacteria
• Free living: Free-living in the soil eg. Azotobacter
• Associative: Living in rhizosphere (associative/associated) without
endophytic symbioses. Eg. Azospirillum
• Symbiotic: Having symbiotic and other endophytic associations with plants.
Eg. Rhizobia, Frankia
– Blue grean algae (Cyanobacteria): have been reported to be helpful in enhancing
rice-field fertility for the cultivation of rice in many parts of the world. BGA can
further provide natural growth hormones, 172 proteins, vitamins, and minerals
to the soil. Eg. Anabaena, Nostoc, Tolypothrix, Cylindrospermum etc.
– Azolla: is a floating pteridophyte, which contains as endosymbiont the nitrogen-
fixing cyanobacterium Anabaena azollae. Azolla is either incorporated into the
soil before rice transplanting or grown as a dual crop along with rice.
, 2. Phosphate solubilizing:
The phosphorus-solubilizing bacteria (PSB) can increase phosphorus availability to
plants by dissolution of bound phosphates in soil by secreting organic acids
characterized by lower pH in their vicinity. Eg. Bacillus spp., Paenibacillus spp.,
Pseudomonas spp. etc.
3. Phosphate mobilizing:
The mycorrhizal fungi form obligate or facultative functional mutualistic symbioses
with more than 80% of all land plants, in which the fungus is dependent on host
for photosynthates and energy and in return provides a plethora of benefits to its
host. The mycelium of the fungus extends from host plant root surfaces into soil,
thereby increasing the surface area for more efficient nutrient access and
acquisition for the plant, especially from insoluble phosphorus sources and others
like calcium, copper, zinc, etc, eg. ectomycorrhiza (Laccaria spp., Pisolithus spp.,
Boletus spp., Amanita spp.), endomycorrhiza (eg. arbuscular mycorrhiza- Glomus
sp., Gigaspora sp., Acaulospora sp., Scutellospora sp., and Sclerocystis sp.)
