Introduction:
Biofertilisers are the organic substances containing living microorganisms, which helps to improve the fertility of soil, plant growth, and yield. Cyanobacteria are the photosynthetic aquatic microorganisms, also called blue-green algae.

Anabaena:
Anabaena is a genus of cyanobacteria, which acts as a biofertiliser. It is a phototrophic bacterium, which can fix atmospheric nitrogen into the soil. Anabaena has the ability to form a symbiotic relationship with the roots of some plants, which helps in the absorption of nutrients from the soil. It is a free-living bacterium, which can colonize the soil and enhance the fertility of soil.

Benefits:
Anabaena has several benefits as a biofertiliser, which are as follows:

1. Nitrogen fixation: Anabaena can fix atmospheric nitrogen into the soil, which helps in the growth of plants.

2. Soil fertility: Anabaena can enhance the fertility of soil by releasing essential nutrients such as phosphorus, potassium, and magnesium.

3. Plant growth: Anabaena can promote the growth of plants by providing essential nutrients and improving the soil structure.

4. Environmental benefits: Anabaena can reduce the use of chemical fertilisers, which can reduce the environmental pollution caused by the chemical fertilisers.

Conclusion:
Anabaena is a cyanobacterial group, which acts as a biofertiliser. It has the ability to fix atmospheric nitrogen into the soil, enhance the fertility of soil, promote the growth of plants, and provide environmental benefits. Therefore, Anabaena can be a potential biofertiliser for sustainable agriculture.