BIOFERTILIZERSPresented by,

M.Uma Maheshwari,

M.Phil Botany

ORGANIC FARMING Organic agriculture excludes the use of

synthetic compounds It mainly rely on usage of organic

substances Organic farming is thus considered as

the movement directed towards the philosophy of “Back to nature”

It emerged as a priority area for growing demand, long term sustainability and concerns on environmental pollution.

Bio fertilizers Bio fertilizers or microbial inoculants are

carrier based ready to use live bacterial or fungal formulations, which on application to plants, soil or composting pits, help in mobilization of various nutrients by their biological activity.

They are the best modern tool for agriculture.

Bio fertilizers contain living micro organisms which promote adequate supply of nutrients

Essential component of organic faming Preparation consists of efficient strains

of Nitrogen fixing, phosphate solubilizing or cellulolytic micro organisms used for application to seed, soil or composting areas

Play a significant role in improving soil fertility by fixing atmospheric nitrogen, with or without plant roots.

Solubilizes insoluble phosphates and promote plant growth.

Need for bio fertilizers Use of chemical fertilizers leads to the

pollution and contamination of soil Demand is much higher than the

availability Energy crisis and increasing cost of

fertilizers Bio fertilizers are economical, eco-

friendly, more efficient, productive and accessible to marginal and small farmers

Characteristic features of some bio fertilizers

Nitrogen fixers› Rhizobium› Azospirillum› Azotobacter› Blue Green Algae (BGA)

Phosphate solubilizers Phosphate absorbers Zinc solubilizers

Rhizobium Rhizobium belongs to the

family Rhizobiaceae Useful for pulse legumes Fix nitrogen 50-100

kg/ha in association with legumes only

Nodulation depends on availability of compatible strain for a particular legume.

Rhizobium Rhizobium has the ability to

fix nitrogen in symbiotic association with legumes and non-legume like Parasponia

It coloniizes the root and produces the nodules, which acts as a factories of ammonia production

Artificial seed inoculation is needed to restore the population of effective strains of Rhizobium near the rhizosphere to hasten N-fixation

Each legume requires a specific species of Rhizobium to form effective nodules

Azospirillum It belongs to Spirilinaceae,

heterophytic and associative in nature

Fix nitrogen about 20 – 40 kg/ha

Many species› A. amazonense› A. halopraeferens› A. brasilense

But A. lipoferum, A. brasilense are worldwide distribution

It has symbiotic association with plants having C4-dicarboxylic acid cycle

They grow and fix nitrogen on salts of organic acids

Mainly recommended for maize, sugarcane, pearl millet, Sorghum, etc.,

They colonize the roots not only on root surface but also penetrates into the root tissues

They do not produce any visible nodules

Azotobacter Belongs to the family

Azotobacetriaceae, aerobic, living and heterotrophic in nature

Many species A. vinelandii, A. baijerinckii, A. insignis and A. macrocytogenes.

A. chroococcum is the most commonly occurring spp.

The number of Azotobacter exceeds 105/g soil due to lack of organic matter and presence of antagonistic organisms

The bacterium produces anti-fungal antibiotics- inhibits pathogenic fungus

Preventing seedling mortality The population is very low in

rhizosphere and uncultivated lands Mainly reported in crop plants like rice,

maize, sugarcane, bajra, vegetables and plantation crops

Blue Green Algae Belongs to eight different families Phototrophic in nature and produces

auxin, gibberllic acid and Indole Acetic Acid

Fix 20-30 kg/ha nitrogen Abundant in paddy fields so called

‘paddy organisms’ Forms symbotic association with fungi,

liverworts, ferns and flowering plants

The most common association had been found between floating aquatic fern Azolla, Anabaena azollae (BGA).

Important character is that it decomposes quickly

The most common species found in India is Azolla pinnata

The fern forms a green mat with a branched stem, deeply bilobed leaves and roots

India has recently introduced some species of Azolla for their large biomass production› A. caroliniana› A. microphylla› A. filiculoides› A. mexicana

Phosphate solubilzers Several reports have reported

that bacterial spp. Can solubilize insoluble inorganic phosphates

Genera like Bacillus, Burkholderia, Achromobacter, Agrobacterium, Microccous, Aerobacter, Flavobacterium and Erwinia

Only considerable populations are seen on the rhizosphere

The soil bacteria belonging to Bacillus and Pseudomonas are common

Phosphate absorbers Mycorrhiza – fungus root Symbiotic association between

host plants and certain group of fungi

The fungal partner is benefited by obtaining carbon requirements

Host is benefited by getting nutrients

They are mainly associated with agricultural crops excepts members of Polygalaceae, Cyperaceae, Amaranthaceae, Caryophyllaceae, Chenopodiaceae, Juncaceae and Brassicaceae

Zinc solubilizers Nitrogen fixers like Rhizobium,

Azospirillum, Azotobacter, BGA and phosphate solubilizing bateria like Bacillus magaterium, Pseudomonas striata and phosphate mobilizing Mycorrhiza can only supply major nutrients to host plants.

Zinc can be solubilized by Bacillus subtilis, Thiobacillus thioxidans and Saccharomyces spp.

Bacillus subtilis can be used as a biofertilizer in soil where native zinc is in higher concentration

Uses 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

Conclusion Biofertilizers are essential components

in maintaining long term fertility and sustainablity by fixing atmospheric nitrogen, mobilizing fixed macro and micro nutrients thereby increasing their efficiency and availability

Organic manures would be a viable option for farmers to increase productivity per unit area.

Therefore reducing pollution and increasing sustainability.

Thank you