questions: asking about the azolla benefits in paddy field 
 answers: suggetion=
it provides nitrogen to the field
it acts as a natural biofertilizer to the crop field
  azolla is rich in proteins, essential amino acids, vitamins and minerals.
it may also be used for the production of hydrogen fuel the production of biogas the control of mosquitoes and the reduction of ammonia volatilization which accompanies the application of chemical nitrogen fertilizer.
it acts as a water purifier.