How much does crop productivity increase with the use of biofertilizers?

Which of the following is a biofertilizer reported to increase rice production by more than $50\%$?

Which one of the following is $NOT$ a bacterial biofertilizer?

The aquatic fern which is an excellent biofertilizer is

Azolla is used as a biofertilizer because it

$S$ - Statement: Organic fertilizers can lead to effective and pollution-free agriculture.
$R$ - Reason: Chemical fertilizers cause pollution.