A brief knowledge about bio fertilizers and their types .

2. INTRODUCTION
• Bio’ means ‘life’. Therefore, by definition bio fertilizers are
living organisms that enrich the nutrient quality of the soil.
It refers to the use of microbes instead of chemicals to
enhance the nutrition of the soil. As a result, it is also less
harmful and does not cause pollution.
• Biofertilizers increase the nutrients of host plants when
applied to their seeds, plant surface or soil by colonizing
the rhizosphere of the plant. Biofertilizers are more cost-
effective as compared to chemical fertilizers.
• This is what makes them so important to organic farming
because they are completely environment-friendly.

3. Types of Biofertilizers:
• Types of bio fertilisers are listed below:-
• 1.Bacteria
• 2.Fungi
• 3.Cyanobacteria
• 4. Earthworm

4. BACTERIA
• The live cells of bacteria are used as a bio fertilizers.
• These microbes contains unique gene called as Nif-Gene
which makes them capable of fixing nitrogen.
• The nitrogen fixing bacteria works under two conditions,
• 1.Symbiotically
• 2.Free living bacteria(non-symbiotic).
• The symbiotic bacteria makes an association with crop
plants through forming nodules in the roots.
• The free living bacteria do not form any association but
lives freely and fix atmospheric nitrogen.

5. Some of the bacteria's are:-
Rhizobium bacteria in
nitrogen fixation
Azospirillum
Azotobacter

6. FUNGI
• Symbiotic associations exist between plants and fungi too.
These associations are called ‘Mycorrhizae’.
• The fungus in this association absorbs phosphorus from the
soil and provides it to the plant. Plants that grow with these
associations also show other advantageous characteristics
such as:
• 1.Tolerance to drought conditions and salinity.
• 2.Resistance to root-borne pathogens.
• 3.An overall increase in plant growth and development.
• In return plants provides it shelter to live.

8. Cyanobacteria
• These are blue-green bacteria found in water and on land.
They also help fix atmospheric nitrogen. Examples
are Oscillatoria, Nostoc, Anabaena etc. The symbiotic
association between the aquatic fern Azolla and Anabaena is
very important for rice fields.
• In this association, Anabaena receives carbon and nitrogen
from the plant in exchange for fixed nitrogen. This adds
organic matter to the soil enhancing the fertility of rice
fields.
• Diazotrophes are cyanobacteria useful for the generation of
eco-friendly biofertilizers which are easily available and less
costly. They can control the nitrogen deficiency in plants,
improve the aeration of soil, water holding capacity and add
vitamin B12.

9. 1.Different types of cyanobacteria's
2.Cyanobacterial bloom

10. EARTHWORMS
• Earthworm has traditionally been known
as friends of farmers due to there basic functions :-
• 1.Turnover of the soil
• 2.production of manure by eating away the organic waste.
• Recently there potentiality to produce manure is
commercially exploited.Growing earthworms on
commercial scale to produce the manure is called as
vermiculture and manure produced by it is called
vermicompost.
• Such manure contains all major nutrients like nitrogen ,
phosphorous, and potassium beside many micronutrients.

11. ADVANTAGES OF BIOFERTILIZERS

12. DISADVANTAGES OF BIOFERTILIZERS