Biofertilzers are biologically active products containing live microorganisms on a suitable carrier used to inoculate seed or soil or both for1) improving plant nutrition,2) stimulating plant growth and 3) accelerating decomposition of plant residues.Use of biofertilizers helps in mobilizing plant nutrients through the activity of organisms contained in it. There are mainly two types of Biofertilizers: 1) Rhizobium used for inoculating legumes 2) Plant growth promoting bacteria (PGPR) which include phosphatic biofertilzers used for inoculating all crops.

Blue green Algae have been reported to fix about 20 kg N per ha. Some of the important genera dominant in rice fields are Anabena, Nostoc, Phormidium,Syctonema, Aulosira, Tolypothrix, etc. They

fix nitrogen in specialized cellular structures called " heterocysts ", which are thick walled and have low oxygen concentration that allows the enzyme nitrogenase to function optimally.

Yes, biofertilizers enrich the soil with nutrients by fixing the atmospheric nitrogen; they solubilize the phosphorous thus, making it available to the plants. They stimulate the growth and development of plants by enhancing the secretion of growth-promoting substances. These are introduced to seeds, roots, or soil to mobilize the availability of nutrients by their biological activity. Thus, they are extremely beneficial in enriching the soil with organic nutrients. Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen. A biofertilizer is a fertilizer made up of living microorganisms. When applied to the field it promotes plant growth by increasing the supply or availability of primary nutrients to the host plant. This helps in increasing the fertility of the soil. Biofertilizers enrich the soil with nutrients by fixing the atmospheric nitrogen, they solubilize the phosphorous thus, making it available to the plants. They stimulate the growth and development of plants by enhancing the secretion of growth-promoting substances. Biofertilizer or biological fertilizer is a material that contains living or dormant microorganisms that colonize the rhizosphere or present inside the plants and directly or indirectly promotes the growth of plants by supplying nutrition. Biofertilizers are microbial formulations constituted of indigenous plant growth-promoting rhizobacteria (PGPR) that directly or indirectly promote plant growth through the solubilization of soil nutrients, and the production of plant growth-stimulating hormones and iron-sequestering metabolites as siderophores. Two kinds of nitrogen-fixing bacteria are recognized. The first kind, the free-living (nonsymbiotic) bacteria, includes the cyanobacteria (or blue-green algae) Anabaena and Nostoc and genera such as Azotobacter, Beijerinckia, and Clostridium. Bacteria such as Rhizobium, Azotobacter, and certain blue-green algae present in the soil fix atmospheric nitrogen in the soil. But Rhizobium plays a vital role in nitrogen fixation. Anabaenas are known for their nitrogen fixing abilities. It is a genus of filamentous cyanobacteria that exist as plankton and forms a nitrogen fixing symbiosis with Azolla to fix nitrogen in the presence of good amount of oxygen. Some bacteria and blue green algae are able to fix nitrogen from the atmosphere to enrich soil and increase its fertility. These microbes are commonly called biological nitrogen fixers. Nitrogen is fixed by the physical method by lightning and biologically by biological nitrogen fixers such as blue-green algae and bacteria e.g. Azotobacter, Rhizobium, Anabaena. Nitrogen is converted to ammonia which is utilised by plants. Blue green algae fix the atmospheric nitrogen which increase the amount of nitrogen in soil hence fertility. bacteria digest the waste material which act as manure. Blue green algae fix nitrogen directly from air to enhance soil fertility. Cyanobacteria which is also called blue green algae is a perfect example of a bio-fertilizer. They work as both nitrogen fixing bacteria and photosynthetic bacteria. Carbon and nitrogen sources are essential for the soil because they help to enhance the soil productivity. Cyanobacteria which is also called blue green algae is a perfect example of a bio-fertilizer. They work as both nitrogen fixing bacteria and photosynthetic bacteria. Carbon and nitrogen sources are essential for the soil because they help to enhance the soil productivity.

Dr Rana Hamza Shakil thank you for your contribution to the discussion

Two kinds of nitrogen-fixing bacteria are recognized. The first kind, the free-living (nonsymbiotic) bacteria, includes the cyanobacteria (or blue-green algae) Anabaena and Nostoc and genera such as Azotobacter, Beijerinckia, and Clostridium. Bacteria such as Rhizobium, Azotobacter, and certain blue-green algae present in the soil fix atmospheric nitrogen in the soil. But Rhizobium plays a vital role in nitrogen fixation. Anabaenas are known for their nitrogen fixing abilities. It is a genus of filamentous cyanobacteria that exist as plankton and forms a nitrogen fixing symbiosis with Azolla to fix nitrogen in the presence of good amount of oxygen. Rhizobia are nitrogen-fixing bacteria that exist in symbiotic relationships with the root nodules of leguminous plants. Some bacteria and blue green algae are able to fix nitrogen from the atmosphere to enrich soil and increase its fertility. These microbes are commonly called biological nitrogen fixers. The organisms like blue-green algae and bacteria are extensively used to fix nitrogen in the soil for agriculture. This will improve the fertility of the soil. Cyanobacteria are key organisms in the colonization of soils and rocks during primary succession in terrestrial communities. Rhizobium is a nitrogen-fixing bacteria found in the root nodules of pulses like peas, green gram etc. The bacteria fix atmospheric nitrogen and provide it to the plants to absorb. In return, the plants provide shelter and nutrition to the bacteria. Cyanobacteria which is also called blue green algae is a perfect example of a bio-fertilizer. They work as both nitrogen fixing bacteria and photosynthetic bacteria. Carbon and nitrogen sources are essential for the soil because they help to enhance the soil productivity. Both free-living and symbiotic species of cyanobacteria are known to fix nitrogen from the air eg: Anabaena, Nostoc, Aulosira, Tolypothrix, etc. Aulosira - It is the most active nitrogen-fixing blue-green alga. These are introduced to seeds, roots, or soil to mobilize the availability of nutrients by their biological activity. Thus, they are extremely beneficial in enriching the soil with organic nutrients. Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen. Biofertilizer or biological fertilizer is a material that contains living or dormant microorganisms that colonize the rhizosphere or present inside the plants and directly or indirectly promotes the growth of plants by supplying nutrition. A biofertilizer is a fertiliser made up of living microorganisms. When applied to the field it promotes plant growth by increasing the supply or availability of primary nutrients to the host plant. This helps in increasing the fertility of the soil. They are efficient in fixing nitrogen, solubilizing phosphate, and decomposing cellulose. They are designed to improve soil fertility, plant growth, and also the number and biological activity of beneficial microorganisms in the soil. Bio-fertilisers are living microorganisms of bacterial, fungal and algal origin. Their mode of action differs and can be applied alone or in combination. Biofertilizers fix atmospheric nitrogen in the soil and root nodules of legume crops and make it available to the plant.

Biofertilizers are organic fertilizers that enrich soil fertility through the act of microorganisms found in the soil. The living microorganisms are crop specific that form a symbiotic association.

Furthermore, I like the discussion and I have learned more things.

Dr Aklil Gebremedhn thank you for your contribution to the discussion

I agree with Gajjela Indira that nitrogen fixing blue green algae is? Anabaenas are known for their nitrogen fixing abilities. It is a genus of filamentous cyanobacteria that exist as plankton and forms a nitrogen fixing symbiosis with Azolla to fix nitrogen in the presence of good amount of oxygen. Biofertilizers are microbial formulations constituted of indigenous plant growth-promoting rhizobacteria (PGPR) that directly or indirectly promote plant growth through the solubilization of soil nutrients, and the production of plant growth-stimulating hormones and iron-sequestering metabolites as siderophores. Biofertilizers play a key role in increasing crop yield and maintaining long-term soil fertility, which is essential for meeting global food demand. Microbes can interact with the crop plants and augment their immunity, growth, and development. Biofertilizers enrich the soil with nutrients by fixing the atmospheric nitrogen, they solubilize the phosphorous thus, making it available to the plants. They stimulate the growth and development of plants by enhancing the secretion of growth-promoting substances. These are introduced to seeds, roots, or soil to mobilize the availability of nutrients by their biological activity. Thus, they are extremely beneficial in enriching the soil with organic nutrients. Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen. It is preferred over chemical fertilizers because it causes very less pollution. Also, it does not allow pathogens to flourish. Various biofertilizers are Rhizobium, Azotobacter, blue-green algae (BGA). Application of Biofertilizers results in increased mineral and water uptake, root development, vegetative growth and nitrogen fixation. Some Biofertilizers stimulate production of growth promoting substance like vitamin-B complex, Indole acetic acid (IAA) and Gibberellic acids etc. They improve plant growth directly by producing plant growth regulators such as auxins, gibberellins and cytokinins; by eliciting root metabolic activities and/or by supplying biologically fixed nitrogen. Consequently, germination, root development, nutrient and water uptake are improved. With respect to plant growth and development, the application of biofertilizers helps to provide sufficient nutrients to the crop during growth enhance root proliferation, safeguard the plant from soil-borne disease attacks, subsequently enhancing the plant growth and development. Two kinds of nitrogen-fixing bacteria are recognized. The first kind, the free-living (nonsymbiotic) bacteria, includes the cyanobacteria (or blue-green algae) Anabaena and Nostoc and genera such as Azotobacter, Beijerinckia, and Clostridium. The Rhizobium or Bradyrhizobium bacteria colonize the host plant's root system and cause the roots to form nodules to house the bacteria. The bacteria then begin to fix the nitrogen required by the plant.