cultivation of azolla, a biofertiliser : A Method demonstration

The Azolla-Anabaena symbiosis has been called a superorganism that combines the individual talents of two very different organisms. The cyanobacterium Anabaena evolved during the early history of the Earth more than three billion years ago when the planet’s atmosphere was devoid of oxygen. The other organism is the fern Azolla.
Azolla’s floating leaves contain cavities filled with nitrogen that replicate the Earth’s ancient atmosphere. These provide a microenvironment for Anabaena which draws down up to 1000 kg of atmospheric nitrogen per acre per year. The nitrogen provides a natural fertilizer for Azolla’s growth, freeing the plant from its reliance on soil and enabling it to grow free floating on freshwater bodies.