Azolla is used as a biofertilizer because it contains:

The main source of biofertilizers is:

Farmers have reported over $50\%$ higher yields of rice by using which of the following biofertilizer?

$A$ water fern, which is used as a green manure in rice fields is

How do mycorrhizal fungi help the plants harbouring them?

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.