• Symbiotic Relationship: Azolla is a free-floating aquatic fern that harbors the nitrogen-fixing blue-green algae (cyanobacterium) Anabaena azollae within its leaf cavities.

• Nitrogen Fixation: The Anabaena converts atmospheric nitrogen into a form that the fern can use. When the Azolla plants die and decompose in the paddy fields, they release this fixed nitrogen into the soil.

• Yield Increase: This process acts as a natural biofertilizer, significantly increasing the fertility of the soil and the yield of paddy (rice) crops, sometimes by up to 50%.