In which fields are $Cyanobacteria$ used as biofertilizers?

Which of the following is not useful as a biofertilizer?

Identify the correct statements regarding mycorrhiza:
$(1)$ Many members of the genus $Glomus$ form mycorrhiza.
$(2)$ It is responsible for all mineral absorption from the soil.
$(3)$ Such associations show benefits against drought and salinity in plants.
$(4)$ Mycorrhiza is a symbiotic association between fungi and roots of higher plants.

How do mycorrhizal fungi help the plants harbouring them?

Which aquatic fern is considered a very good biofertilizer?

In paddy fields, . . . . . . serves as an important biofertiliser.