The mosquito fern or Azolla is one of the most important bio fertilizers. In association with which among the following Azolla acts as a biofertilizer?
Bio-fertilizers such as Rhizobium, Azotobacter, Azospirillum and blue green algae (BGA) have been in use a long time. Anabaena, a blue green alga in association with water fern Azolla contributes nitrogen and also enriches soils with organic matter.
This question is a part of GKToday's Integrated IAS General Studies Module